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Stephanie Norris Architects
BROWNE’S HOSPITAL: STAINED GLASS CONSERVATION
For the Trustees of Browne’s Hospital
SPECIFICATION & SCHEDULE OF WORKS July 2020
Browne’s Hospital: Stained Glass Conservation: Specification & Schedule of Works
1924-SPEC-020720 Page 2 of 49
STEPHANIE NORRIS
BA(Hons) BArch DipAM RIBA AABC
Stephanie Norris Architects Ltd
8 The Coppice
Impington
Cambridge CB24 9PP
Tel: 07786 360552
All rights in this work are reserved. No part of this work may be reproduced, stored or
transmitted in any form or by any means (including without limitation by photocopying or
placing on a website) without the prior permission in writing of Stephanie Norris Architects Ltd
except in accordance with the provisions of the Copyright, Designs and Patents Act 1988.
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CONTENTS
1.0 Preliminaries 4
2.0 General Obligations 8
3.0 Specification: Trade Clauses 16
4.0 Schedule of Works 28
5.0 Collection Page 36
Appendix 1: Photographs 37
Appendix 2: The CVMA Numbering System 46
Appendix 3: List of abbreviations to be used on stained glass diagrams 47
Appendix 4: Form of Tender 48
Appendix 5: The York Glaziers Trust Report and Condition Advice 2017 (separate doc)
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PRELIMINARIES
A1 NAMES AND ADDRESSES
Employer:
The Trustees of Browne’s Hospital, Stamford
c/o Mr David Wallington (Trustee) 67a Casterton Road
Stamford
PE9 2UB
07721 343618
Architect:
Stephanie Norris
Stephanie Norris Architects Ltd
8 The Coppice
Impington
Cambridge CB24 9PP
07786 360552
Principal Designer:
Philip Waller
Philip Waller Consulting
Meadow House
Longmeadow
Brundall
Norwich NR13 5LY
01603 959788 | 07471 655642
A2 DESCRIPTION OF SITE
Location of site: Browne’s Hospital, Broad Street, Stamford PE9 1PF
Access and confines of working area for Contractor, to be agreed at Pre-contract site
meeting.
The Contractor is deemed to have visited the site, to have taken into consideration all
local and existing conditions and to have made himself thoroughly acquainted with the
position and accessibility of the proposed works and the conditions under which they will
have to be carried out. Arrangements for visiting the site shall be by appointment only.
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A3 DESCRIPTION OF THE WORKS
The work is to include the necessary conservation glazing repairs and fabrication and
installation of an environmental protective glazing (EPG) system to Chapel windows sII
and sIII, Audit Room windows sII, sIII and sIV and nII, and the small Entrance passage
window (un-numbered – ‘EPW’). See locations on dwgs 1924/101 and 102.
The work to also include a few, relatively minor, stonework repairs needed to some
mullions, tracery and stone surrounds.
A4 CONTRACT DOCUMENTS
The Contract Documents will be the same as the tender documents, incorporating the
main contractors priced schedule of work, and will be as follows:
1. The Specification & Schedule of Work (hereafter called the Specification).
2. The JCT Minor Works Contract 2016 Edition, as described in specification item A5.
3. The following drawings: 1924/101, 102, 103, 104
A5 CONTRACT PARTICULARS
The form of contract will be the JCT Minor Works Building Contract, 2016 Edition. The
following is operative:
Attestation The agreement will be executed under hand.
4th Recital &
Schedule 2
Base date 3 working days prior to the
date for tender return
4th Recital &
Clause 4.2
Construction Industry Scheme (CIS) Employer at Base Date is
not a contractor for the
purposes of the CIS
5th Recital CDM Regulations The project is not
notifiable
6th Recital Framework Agreement N/A
7th Recital &
Schedule 3
Supplemental Provisions
Collaborative working Supplemental Provision 1
applies
Health and safety Supplemental Provision 2
applies
Cost savings and value improvements Supplemental Provision 3
does not apply
Sustainable development and environmental
considerations
Supplemental Provision 4
does not apply
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Performance indicators and monitoring Supplemental Provision 5
does not apply
Notification and negotiation of disputes
Supplemental Provision 6
does not apply
Article 7 Arbitration Article 7 and Schedule 1
(Arbitration) apply
2.2 Works commencement date To be agreed
2.2 Date for Completion To be agreed
2.8 Liquidated damages At £100 per week
2.10 Rectification Period 12 months from the date
of Practical Completion
4.3 Interim payments: Interim Valuation Dates The first Interim Valuation
Date is TBC and
thereafter at intervals of
1 month
Payments due prior to practical completion –
percentage of the total value of work etc.
95%
Payments becoming due on or after practical
completion – percentage of the total amount
to be paid to the Contractor
97.5%
4.3 & 4.8 Fluctuations provision no fluctuations provision
applies
Percentage addition for Schedule 2 N/A
4.8.1 Supply of documentation for computation of
amount to be finally certified
3 months from the date
of Practical Completion
5.3 Contractor’s Public Liability Insurance: injury
to persons or property (for any one
occurrence or series of occurrences arising
out of one event)
£5M for each and every
claim
5.4A, 5.4B & 5.4C Insurance of the Works etc. – alternative
provisions
Clause 5.4B applies
(Works & existing
structure insurance by
Employer in Joint Names)
5.4A.1, 5.4B.1 &
5.4C.1
Percentage to cover professional fees 15%
9.4.1 Adjudication The Arbitrator is the
President or Vice-
President of the Royal
Institute of British
Architects
The Conditions Contract Guarantee Bond Not required
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A6 TENDERING
Tendering procedure
In accordance with the principles of: JCT Practice Note 6 (Series 2) 'Main Contract
Tendering'.
Arithmetical errors: Alternative 1 is to apply.
General: Tenders must include for all work shown or described in the tender documents
as a whole or clearly apparent as being necessary for the complete and proper
execution of the Works.
Exclusions
Inability to tender: Immediately inform if any parts of the work as defined in the tender
documents cannot be tendered.
Relevant parts of the work: Define those parts, stating reasons for the inability to tender.
Acceptance of tender
No guarantee is offered that any tender will be recommended for acceptance or be
accepted, or that reasons for non-acceptance will be given.
Costs: No liability is accepted for any cost incurred in the preparation of any tender.
Period of validity
After submission, keep tender open for consideration for not less than 12 weeks.
Priced documents
Alterations: Do not alter or qualify the priced documents without written consent. Tenders
containing unauthorised alterations or qualifications may be rejected.
Measurements: Where not stated, ascertain from the drawings.
Deemed included: Costs relating to items which are not priced, will be deemed to have
been included elsewhere in the tender.
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GENERAL OBLIGATIONS
Statutory
Obligations
Comply with statutory obligations and regulations, give all notices, pay all
fees and charges required by any Local Authority, Public Service or Statutory
Undertaker, Police, Safety, Health and Welfare.
Give notice to the Local Authority for inspections at all necessary stages
required under the Building Regulations. Ensure a Notice of Completion is
issued by the Local Authority to the Employer as soon after Practical
Completion as possible.
Prevention of
Accident/
Nuisance
Take all reasonable precautions necessary to prevent accidents or nuisance
due to fire, noise, dust, smoke, water, rubbish etc.
No radios to be used on site.
Prevention of
Damage/Loss
a) Public and Private Services
Notify all service authorities of proposed works before commencing site
operations. So far as reasonable ascertain location of services or confirm that
none exist in the vicinity of the works.
b) Maintenance of Roads etc.
Make good any damage beyond fair wear and tear caused by site traffic or
site operations to Employer’s private roads and footpaths.
Keep approaches to the site clear of mud and debris.
c) Trees and Shrubs
Protect and preserve all trees and shrubs except those to be removed, in
accordance with BS 5837 Trees in relation to design, demolition &
construction. Large shrubs growing on the walls are to be pulled back
carefully and given temporary support wherever possible.
d) Existing Features
Protect existing buildings, fences, gates, walls, paved areas and other site
features that are to remain in position during execution of the works.
Asbestos
Containing
Materials
Report immediately any suspected materials discovered during execution of
the Works.
Do not disturb.
Agree methods for safe removal or encapsulation.
Progress a) Programme
Prepare in an approved form a programme chart for the works, including
work of all domestic and nominated subcontractors and other work
concurrent with the Contract.
Submit three copies of programme to the Architect at least one week prior
to contract commencement and keep one copy in the site office.
Record progress on the site office copy and update/redraft as circumstances
arise and submit all revisions to the Architect.
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b) Site Meetings
Hold monthly progress site meetings and attend weekly site visits.
Resources,
Temporary
Works & Services
a) General
Maintain, alter, adapt and move temporary works and services as necessary.
Clear away when no longer required and make good.
b) Buildings
Provide as necessary temporary facilities for offices, mess rooms, sanitary
accommodation, secure stores for materials etc as required for your own use.
c) General Scaffolding
Provide as necessary general scaffolding for the execution of the works.
d) Name Board
Obtain approval for and provide a suitable temporary name board
displaying consultants and contractors name plates.
e) Telephone
Provide temporary telephone facilities for your own use.
f) Water, Lighting & Power
Provide clean, fresh water, electricity and all equipment for lighting and
power for the works, make temporary arrangements for storage (water) and
distribution about the site. Provide lighting for any temporary hoardings and
the like.
g) Plant Costs
Provide all plant, tools and vehicles for the execution of the works.
h) Labour Costs
Allow for all labour on costs.
Commodities & Workmanship
Quality, Testing
& Approvals
a) Commodities
To be new unless otherwise specified. Handle, store and fix commodities with
care to ensure that they are in perfect condition when incorporated into the
work.
b) Manufacturers’ Recommendations
Handle, store and fix each commodity in accordance with manufacturers’
recommendations. Inform Architect if this conflicts with any other specified
requirement. Submit copies of manufacturers’ recommendations to
Architect when requested.
c) British Standards
For commodities specified to a British Standard obtain certificates of
compliance from manufacturers when requested by Architect.
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d) Samples: Commodities
Where approval of commodities is specified submit samples. Do not confirm
orders for commodities until approval has been obtained. Retain approved
samples on site for comparison with commodities used in the Works. Remove
when no longer required.
e) Samples: Finished Work
Where samples of finished work are specified obtain approval before
proceeding with the works. Retain approved samples on site for comparison
with the works. Remove when no longer required.
f) Building Regulations
Main Contractor to ensure regular site visits by Building Inspector as required
under Building Regulations and obtain the Completion Certificate at the end
of works.
Accuracy a) Setting Out
Set out the works accurately from information provided by the Architect.
Inform the Architect when overall setting out is complete and before
commencing construction.
b) Dimensions
Check all dimensions both on drawings and site, particularly the correlation
between components and the work in place. Drawings must not be scaled,
work only to figured dimensions.
c) Discrepancies
The Architect must be notified of any discrepancies in the drawings or
specification immediately.
Protection a) The Site
Safeguard the site, works, materials and plant from damage and theft. Take
all reasonable precautions to prevent unauthorised access to the site, works
and adjoining property.
b) Cleanliness
Keep the site and works clean and tidy. Clear away debris and surplus
material as it accumulates.
Drying Allow for drying the works.
Completion Leave the works clean and tidy at completion.
Nominated Firms/Public Bodies
Prime Cost or
Provisional Sums
For all work to be executed or commodities to be supplied by nominated
subcontractors, nominated suppliers or public bodies have been included
elsewhere in the contract documents.
Warranties Forms of Warranty will be sought by the Employer from all nominated firms.
You should not enter into subcontracts until you are satisfied that Forms of
Warranty exist.
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General
Attendance
Provide general attendance on nominated firms and public bodies
including:
a) Use of standing scaffolding.
b) Use of general facilities.
c) Space for office accommodation, storage of plant and of materials.
d) Light, power and water.
e) Clearing away rubbish.
Supervision &
Administration
Accept responsibility for the supervision, administration, co-ordination and
integration of work of all subcontractors, suppliers and public bodies.
A complete set of legible contract drawings must be kept on site at all times.
Update as necessary and make available for Architect’s use as required.
Daywork No additional work is to be carried out the value of which cannot be
ascertained from the priced specification without the prior agreement of the
Architect except where this would prevent the Contractor fulfilling his
obligation under the Contract.
Maintenance
Instructions
Copies of maintenance instructions and guarantees shall be obtained from
subcontractors and manufacturers as required and given to the Architect
within 14 days of Practical Completion.
Fire Precautions Take all necessary precautions to prevent personal injury, death and
damage to property and the fabric from fire. This care is to include:
a) No smoking on site.
b) No burning of rubbish on site. All rubbish must be removed from site.
c) Inflammable materials must not be stored on site.
d) Hot Work
The general rule is that hot work is prohibited on site. In certain circumstances
permission may be given where there is no practical alternative. If the
Contractor wishes to carry out hot work he should make a prior application
to the Architect for written consent.
Hot work is defined as operations involving:
Flame, hot air or arc welding and cutting equipment brazing and soldering,
blowlamps, bitumen boilers, electrical element burners and other equipment
producing naked flame and heat (e.g. high-speed drilling of any hard
material which may be combustible or near combustible material).
Where the Architect’s written permission has been received the contractor is
to take all precautions to minimise fire risks.
Where prefabrication and Hot Work e.g. lead burning can be carried out at
a minimum distance of 6 metres outside the building, on the ground and with
no combustible materials within 6 metres of the Hot Work operation, it should
be. Only as a last resort should hot work be carried out from the scaffolding
or in the building.
Precautions to minimise fire risks should include:
i) Removal of combustible materials as agreed with Architect. Cleaning the
area to remove dust and rubbish.
ii) Ventilation of enclosed spaces.
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iii) Prior saturation with water of combustible materials that cannot be
removed as agreed with Architect.
iv) Temporary covering of immovable combustible surfaces with a 50-75mm
thickness of damp sand as agreed with Architect.
v) Removal of containers of inflammable gases or compressed gases.
vi) Protection of surrounding areas with flame retardant boards or other
suitable fire-resistant material.
vii) The use of butane and not paraffin lamps where appropriate.
viii) Confining the Hot Work to mornings only.
The Contractor is to provide firefighting equipment including:
i) Two portable extinguishers, buckets of water or sand to be immediately to
hand.
ii) Fire hoses to hand (where appropriate and practical).
iii) Adequacy of water supply, and water pressure.
iv) Knowing the location of the nearest telephone. Builder’s tools for opening
up roofs, walls, telephone floors, etc.
v) Alerting the fire brigade of the time and location of the Hot Work.
Where the building has automatic fire detection systems the Contractor
should make themselves aware of the Fire Instructions and procedures to be
followed in the event of a fire.
The operatives to carry out the Hot Work are to be suitably qualified and
experienced.
Numbers to be involved never to be less than 3 (i.e. 2 in addition to the
experienced operative for standby surveillance).
Following Hot Work the contractor shall remain at the location for at least 1
hour after completion of the task (except for any essential minimum break, in
which event alternative cover must be provided), during which time
continuous inspections of the work shall be made with particular reference to
the surrounding area to ascertain that there is no ignition.
A further inspection shall be made approximately 2 hours after the cessation
of the Hot Work by the Contractor in conjunction with one of the standby
operatives.
A record shall be made of the Hot Work by the Contractor and shall be sent
to the Architect for filing with original written consent. This record is to include
times, locations and subsequent checking information.
Fire extinguishers and appropriate fire-fighting equipment must be to hand
during the whole of the attendance time.
NOTE: It may be prudent to advise Insurers in advance of the Hot Work
operation so that they can inspect and, if necessary, approve procedures to
be adopted.
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Policy Note
(Fire) 4/92
Use of Portable Halogen Lamps
The use of portable halogen lamps for building and conservation works is
barred. This does not affect the use of halogen lamps that are permanently
secured, for such uses as floodlighting security lighting or emergency lighting.
In these instances:
i) The angle of the lamp must be secured.
ii) The lamp must be fitted with a metal guard to avoid contact with any form
of material.
iii) No combustible material or fitting which may be used for attaching
combustible material shall be within two metres.
Hand held battery operated halogen lamps for conservation inspection work
are not affected by this instruction.
Fluorescent, single or multi tube fittings are a low heat producing source and
is one acceptable alternative.
Bats The Wildlife and Country Act 1981 gives full protection to bats. It is illegal to kill,
injure or handle bats and to intentionally damage or destroy a place used by
bats for shelter or protection, or to obstruct access to such a place.
Information on looking for bats etc in buildings is available from Natural
England. Ensure employees and visitors to the site receive suitable instruction
and awareness training.
During the works, if the Contractor finds evidence of bats in the building he is
to immediately:
i) Stop work.
ii) Contact Natural England.
iii) Inform the Architect.
The Contractor is not to proceed with work until instructed by the Architect in
writing.
Timber Treatment
Under no circumstances shall organochlorine woodwork killers (eg lindane)
and fungicides be used. Synthetic pyrethroid insecticide, such as permethrin
and cypermethrin can be used by an approved timber specialist.
Antiquities and
Excavations
Any fossils and other objects of interest or value which may be found on site
or within the fabric of the building or during excavations are the property of
the Employer. On discovery of such objects the Contractor must immediately:
a) Cease work. Keep objects in the exact position and condition in which
they were found.
b) Advise the Architect immediately. It may be necessary to call in an
Archaeological Advisor to inspect.
The Contractor is not to proceed with work in the area until instructed by the
Architect in writing.
Health & Safety CDM Regulations 2015
The Contractor must take all reasonable steps to ensure the Health & Safety
of those working on and visiting the construction site in accordance with all
relevant Codes of Practice.
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The Contractor must allow for full compliance with the current CDM
Regulations and, where required, give notice of the project to the Health &
Safety Executive prior to construction work commencing (normally for work
lasting more than 30 days and involving 20 or more workers at any one time).
Where projects are notifiable or where more than one contractor is involved
in the works or the Contractor is to employ one or more subcontractors, then
the Contractor, unless otherwise stated, must allow for providing the role of
Principal Contractor (PC) within the meaning of the CDM Regulations. This will
involve liaising with the separate contractors on all matters concerning health
and safety on the site and ensuring proper coordination of all the work on
site.
Where more than one contractor is involved in the works or the Contractor is
to employ one or more subcontractors, the Employer will ensure that a
Principal Designer (PD) is appointed for the project and they will be
responsible for issuing Pre-Construction Information and ensure that a Health
and Safety File for the project is prepared on completion.
At the time of tender, Contractors must allow for full compliance and Health
and Safety obligations.
The PC when appointed must:
a) Prepare a Construction Phase Plan (CPP) prior to starting work. The CPP
must be acceptable to the PD and submitted in good time.
b) Discuss and advise all subcontractors with regard to the requirements of
the CPP.
c) Demand the full co-operation of all subcontractors.
d) Ensure that all subcontractors employees are informed of on-site risk and
know enough about the CPP to comply with it.
e) Perform the same function with all of his own direct employees.
f) Take reasonable steps to keep unauthorised persons off site.
g) Update the CPP throughout the duration of the job.
h) Provide the necessary information to the PD to enable him to include that
information in the Health and Safety File.
i) Provide adequate training to all site operatives.
j) Consider all site generated risks and hazards including those arising from the
design. These should be notified to the PD.
k) The Health & Safety Executive no longer deems the use of ladders and
working on flat roofs to be safe. They recommend that no work is carried out
from a ladder over five metres high. If the ladder is over five metres it must be
secured to approved and tested fixings, it is not acceptable to have an
operative footing a ladder. Flat roofs must have parapets a minimum of 1100
mm high. If this is not the case a handrail must be erected, whatever the size
of the project. It is no longer acceptable to work overhand, for example
bedding coping stones unless a safety line exists.
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SPECIFICATION: TRADE CLAUSES
LEADED LIGHT GLAZING
To be read in conjunction with Preliminaries and Schedule of Work
Outline Scope of Work for existing stained glass leaded lights
Stained glass and leaded light glazing to only be carried out by an approved specialist glazier
with ICON accreditation to appropriate level.
Removal of stained glass and installation of protective glazing
In situ
photographic
recording
Photograph digitally all panels internally from the scaffold access in
transmitted and reflected light and externally in reflected light. These
general overall photographs must be supplemented with detail
photographs of any damage, defects or discoveries made before
removal.
a) Each photograph is to be named giving its window and panel number
and filed within folders for each window.
b) Three copies of these photographic records are to be prepared on CD
or DVD, one set for the Client, one for the Architect and one for the
contracted conservation studio.
Numbering of
glazing panels
Each glazing panel is to be numbered following the CVMA numbering
system. (See Appendix 2.) Acid free labels with each window and panel
number clearly printed on them are to be attached to the external face
of the panels. Ensure that the selected position to apply the label is free
from surface dust and has no back painting.
Inspection and
recording insitu
Inspect glazing and record existing damage, defects and support systems.
Inspect each panel and related fabric. Make written record of site specific
conditions such as saddle bar installations, noting material, profile, sizes
and location; cill, head and jamb details; damage and discoveries.
Provide 2no. hard copies of the inspection report to the Architect.
Protection of the
works area
Prior to commencing of removal works, protect the work area by dust sheet
covering the scaffold boards and the stained glass where necessary with
Correx box sheeting to prevent damage from mortar debris. Provide safe
panel racking system to store removed stained glass on the scaffolding on
removal, prior to lowering to the ground.
Removal of
mortar and putty
Remove mortar from the glazing grooves using conventional hammer and
chisel techniques aided where found helpful with a Fein oscillating tool or
equivalent. Keep work areas regularly clean by sweeping up debris and
bagging for disposal. Note: the mortar may be cement rich and hard.
Proceed carefully to avoid undue damage to the stonework.
Remove putty from saddle bars as found necessary to enable safe removal
with hand tools or Fein oscillating tool or equivalent. Keep work area
regularly clean by sweeping up debris and bagging for disposal.
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Taking of
templates
Take all required measurements and templates of window opening, jamb,
mullion and cill profiles. Consider bar positions and take measurements to
calculate parallax compensations for the protective glazing layer.
Fabrication of
protective
glazing
New clear external protective glazing:
Manufacture protective glazing panels to suit existing stone window
surrounds made from clear Glashütte Lamberts restauro glass and milled
lead. Alternative glasses may be used by agreement of client, architect and
other stakeholders. Provide new bronze saddle bars, matching sizes of
saddle bars to stained glass panels,
Design of leadwork setting out for each window to be as set out in the
Schedule of Works.
The head and tracery shapes are to be in full panes but may be divided at
critical stress points presented by the tracery shapes.
The protective glazing is to be leaded with perimeter cames in 5/8″ flat profile
with ½″ uneven & U lead divisions and 3/16″ break leads within the tracery
shapes.
Prior to leading protective glazing, allow for a bead of neutral curing silicone
to be run along the heart of the perimeter came before inserting the sheets.
The protective glazing cames to be hand sealed after the silicone has cured
with black linseed oil putty.
If lead condensate trays are scheduled to be provided, account for these
within new glazing panels.
Condensation
trays
Provide where instructed by the Schedule of Works.
Provide at each window cill bay in code 5 sand cast lead, with 35mm
upstand, dressing neatly into junctions with horizontal and vertical surfaces.
Provide 2 no. lead wedges to each light below the bottom edge came to
hold glazing panel above condensation groove.
Preparation on
site for
transportation
/Panel removal
Prepare panels for transportation by securing any fractured pieces that are
considered at risk by taping on the unpainted side with 3M Magic tape.
a) Prepare suitable identification labels and attach to the support bars
prior to removal.
b) Prior to removal, cut through the copper wire ties from around the
support bars of each panel and fold back.
c) Ease perimeter lead cames and carefully remove the glazing from the
openings.
d) Snip off the excess copper wire ties to as near to the soldered joint as
possible and ease back to avoid any damage from protruding points.
e) Set aside the removed panels in a safe and unobtrusive position on the
scaffolding on the secure racking.
f) In appropriate stages manually carry the removed panels from the
scaffolding. Store in temporary racking system ready for transportation to
the studio.
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g) Chip out around the through bar pockets and carefully remove the
saddle bars from the stonework.
A conservation record sheet is to be attached with each panel and
tracery section. Specified documentation will be listed on the sheet
covering its period of treatment. Fill in each sheet with the specified
information required prior to studio treatment.
Each panel to be transported in suitable packing cases or glass rack. The
panels are to be packed in such a way to ensure that no packing is in
contact of the glass surfaces. Use Coroplast board for packing or
equivalent non-acidic board.
Transport window and through bar to studio for treatment.
Installation of
protective
glazing (within
existing stone
grooves)
Fix code 5 lead condensation trays with 35mm up-stand to the cills of the
window openings.
Fix the new protective glazing within the existing stone grooves.
The pointing of the protective glazing to be in hydraulic lime mortar or to
the architect’s specifications. The pointing must allow for possible structural
movement.
The lead condensation tray to be filled with aquarium gravel to a level
sufficient to prevent ingress of air from the exterior.
Cleaning of
plain glazing
All diamond quarry pattern plain glazing to be cleaned to both interior and
exterior sides.
Panels to be brushed down with soft brushes to remove surface dust and
cobwebs before swabbing with deionised water on microfibre cloths.
Studio Work
Assessment In the studio and prior to any conservation work each panel is to be
thoroughly assessed using binocular microscopes to ensure that no further
damage is caused during the cleaning process.
Post removal
photographic
recording
Photograph each panel on the light box in both transmitted and reflected
light conditions.
a) Additional detailed photographs are to be taken of areas of damage
or special interest.
b) The photographs are to be taken in a high resolution digital format. Each
photograph is to be named giving its window and panel number and filed
within folders for each window.
c) Three sets per window of the digital images are to be saved on CD or
DVD. Provide one set for the Client, one for the Architect and one for the
contracted conservation studio. Two complete sets of all the images are
to be downloaded onto external hard drives.
Condition
record -
rubbings
Make two sets of pre-conservation full size rubbings of each panel on detail
paper. One set as a re-leading working sheet and another as a record,
annotated with details listed with information detailed in the list of
abbreviations to be used on stained glass diagrams. (See Appendix 3)
Browne’s Hospital: Stained Glass Conservation: Specification & Schedule of Works
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a) Mark each rubbing with the following information across the top band
of each rubbing in a clear, readable manner.
1. Window number and panel number.
2. Measured full size of the panel.
3. A ruled marking strip to indicate scale details.
b) On completion of the re-leading take a post conservation rubbing and
annotate with details listed with information detailed in the list of
abbreviations to be used on stained glass diagrams.
Leading Re-leading of the panels is not required; however allow for the renewal of
damaged perimeter cames and others removed to undertake bonding
repairs to edge pieces.
Further interventions to be discussed and agreed on a panel by panel
basis. Such interventions may include, for example:
• Repair leads inserted during the last re-leading to have their leafs either
totally removed to expose the fine line of the came heart or pared back
to reduce the visual impact. The decision made by the conservator to
undertake these procedures must ensure that the glass pieces are held
mechanically within the main leadwork.
• Pieces that are star fractured or severely disfigured by the addition of
dense mending leads are to be repaired within the panels. Allow for either
partial dismantling of the panel to expose the repair pieces or remove the
face leaf to extract the pieces from the repair section. Repair disturbed
leading as found necessary after completing and reinstating the glass
repairs. Any necessary repair leads that are required are to be as fine as
practicable (1/8″ or less).
Sections of lead work disturbed during the process of repair are to be hand-
sealed with traditional black putty to the external came leaves only.
Stained Glass
repairs and
cleaning
Fractured pieces removed from the panels for repair are to be edge-
bonded where clean break edges are exposed with CAF3 silicone
adhesive or approved alternative silicone.
Multi-fractured bonded pieces not held mechanically by the lead came
or other mechanical methods are to be supported by a kiln-moulded 1mm
backing plate. The edges of the backing plate and the bonded pieces are
to be sealed with neutral curing silicone.
Cleaning of the glass surfaces should be carried out with the aid of
binocular microscopes. The suggested cleaning method may be applied
generally but it is important that the conservator overseeing the project
inspects each piece and makes considered judgements as to whether
swabbing is safe to undertake. If it is considered that the swabbing will
remove or damage the pigment, the cleaning of these pieces should be
restricted to light dusting down only.
The glass which only has light deposits of grime on the external surface is to
be cleaned by swabbing with deionised water. Further cleaning to remove
mortar splashes, heavier deposits of grime and deposits of corrosion may
be removed by light brushing with stiff bristle brushes or scalpels as found
necessary.
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The internal painted surfaces are found with light deposits of dust and
cobwebs. The internal surface may be safely cleaned by first dusting down
with soft hair brushes to remove the light dust and cobwebs. The sooty
deposit can be removed by lightly patting the surface with cotton wool
swabs, dampened with deionised water. The addition of ethanol to
deionised water (50:50) may be employed to assist with the cleaning if
found necessary. (Note: no wiping action is permitted to clean the painted
surfaces).
Stained Glass
framing
Frame the main light stained glass panels to form unit sections in 10 x 12 x
2mm ‘U’ profile manganese bronze to the perimeters of each main light.
Tracery shapes with acute curves to be framed in 6 x 12 x 2mm ‘U’ profile
manganese bronze.
Fix flexible 1 x 10mm phosphor bronze fixing brackets with 4.5mm fixing
holes formed within them to the sides of the U section. The brackets to be
positioned at approximately 200-250mm intervals and secured to the U
section with solid copper rivets and soldered.
The division of the frames to be made in ½″ x ½″ x 1/16″ bronzed brass ‘T’
section to form a stacking method.
Cut new intermediate support bars in either ½″ x ¼″ or ⅜″ x ¼″ rectangular
section bronzed bar to match the profile and dimensions of the existing
support bars. The new bars to be soldered directly to the inner profile of the
‘U’ sections; alternatively mechanical joining methods may be employed.
Re-band the panels during assembly into the frames in tinned 3/16″ flat
copper strip.
Solder bracing plates across all joints of the framed sections; alternatively
mechanical joining methods may be employed.
Solder 1″ leaf lead light shields to the perimeters of the external face of the
framed sections.
Reinstallation of Stained glass
Transportation
from studio to
site
Each panel to be transported back to site in suitable packing cases for
glass and bronze frame. The panels are to be packed in such a way to
ensure that no packing is in contact of the glass surfaces.
Use Coroplast board for packing or equivalent non-acidic board.
Protect the components during transportation.
Reinstate
stained glass
panels
Offer the framed sections to the front face of the openings to determine
the best position whilst maintaining an equal gap to perimeter to allow
passage of airflow.
Drill the marked positions with a 6mm drill bit and insert a suitable stone
anchoring nylon plug, such as those produced by Fischer.
Screw the framed sections in position with brass, bronze, stainless steel or
other suitable non-ferrous screws.
Fold the leaf lead light shields down to the stonework to hide any side light
and ease open at appropriate positions to form small gaps to allow
adequate ventilation to top and bottom of each window opening.
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STONEMASON
Materials
Stone generally Stone is to be sandstone or limestone, free from natural defects including
hairline fractures, quarried without the use of explosives and selected by the
quarry and stonemason for the use and position in which it will be
incorporated in the finished work.
All stone is to be selected, worked and marked so that it will be laid in position
in the building on its natural bed, except for copings, string courses, hood
moulds and tracery heads, where the stone bed must be perpendicular to
the weathered face, and voussoirs or arches where the bed shall be
perpendicular to the line of thrust.
Generally provide samples of new stone to match existing surface texture,
finish or special detail.
Limestone Clipsham from Stamford Stone Co., Swaddywell Quarry, Stamford Road,
Helpston PE6 7EL.
Note: Stone to be sourced from former Clipsham Quarry Company, Clipsham
Hall, Clipsham, Oakham, Rutland LE15 7SE; contractor to provide evidence
that material has been obtained from this quarry, not 'Medwells Quarry'.
Ironstone Supplier: The Great Tew Estate, The Estate Office, New Road, Great Tew,
Chipping Norton, Oxon OX7 4AH.
Cramps &
Dowels
All new work, repairs, rebuilt work are to be properly cramped and dowelled
together and to adjoining fabric.
Cramps and dowels are to be stainless steel or phosphor bronze
(specification PB102), purpose made and recommended by the
manufacturer for the particular application and site conditions.
Allow for careful removal of all existing iron cramps etc found in existing work
where repairs are being undertaken. Replace removed cramps etc with
stainless steel or phosphor bronze where necessary.
If old cramps cannot easily be removed without damaging adjacent
stonework, wire brush and treat with 2 coats Fertan Rust converter from:
Fertan UK, King & Queen House, High Street, Hamble, SO31 4HA
Tel 02380 456600, Email [email protected]
Workmanship
General The work is to be carried out by qualified stonemasons working for an
approved stonemasonry contractor.
Identification Arrange review inspection with Architect before starting work. Confirm
type and extent of work required.
Mark identified stones clearly, but not indelibly, on face of masonry units or
parts of units to be cut out and replaced and cross-reference to drawings/
photographs.
Before starting work, use measurements and photographs as appropriate
to record bonding patterns, joint widths, special features, etc.
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No stone shall be ordered until the stone for replacement has been
identified on site by the Architect who reserves the right to substitute repairs
for replacement of selected stones.
The stonemason is responsible for taking his own site dimensions and making
his own templates and preparing stonework and shop drawings. Shop
drawings to be submitted to the Architect for approval.
Piece Repairs
Where string courses and hoodmoulds are to be piece repaired, the specialist
stonemason is to cut the existing stone back by a minimum depth of 125mm
to a square surface, and dowel and glue the new stone to the remaining
existing stone.
The Architect may give directions for complete replacement if the depth of
existing stones in the wall is less than 200mm.
All piece repairs to weathering surfaces are to be cut under existing flintwork
or stonework by a minimum of 75mm to prevent rain penetrating behind
repairs.
All adhesive used is to be acrylic resin recommended for masonry work by
the manufacturers, such as Sebralit Solid or equal approved, and used strictly
in accordance with the manufacturer’s recommendations.
In connection with stonework repairs allow for all cutting out, numbering of
stones etc, removal of glazing/louvres etc where appropriate and for refitting
same after work complete.
Resin pinning
fractured stone
Use Acrylic resin for piecing in and fixing cramps, bar reinforcement,
armatures etc. Manufacturer and reference: Sebralit Solid
Pins to be Stairib 460 Deformed Round Bar 6mm diameter in Grade 18/8
Austenitic Stainless Steel 460 Nmm². By George Clark (Sheffield) Ltd or similar
supplier approved by the CA.
Mortar Repairs
generally
The stone mixture is to be in a 3:1 mix aggregate: lime. The defective stone is
to be cut back to a firm base drilled and laced with stainless steel wire or
grade 316 pins to provide a skeleton framework for the repairs. The wire must
not come closer than 25mm (1”) to the finished stone surface. Where
necessary polyester adhesives are used to hold the armature in place.
Masonry joints are to be retained in the finished repair and the mix adjusted
to match the existing stone in colour and texture, without using cement
colourings. Where repair is too shallow for an armature, key by drilling into the
stone and wet surface before applying the lime mortars.
Mortar Repairs
application
Pre-clean all retained work to match surrounding cleaned work.
Carry out consolidation as agreed on site with the Architect.
Friable stone faces to be descaled and defrassed. Undercut top edges to
protect feather edges from weather and to vertical and bottom edges
provide slurry/mortar repair to discourage ingress of water.
The area to be repaired should be well wetted and particularly friable stone
should be treated with 3 coats of slurry mix.
Water is added to this mix to achieve a thin creamy consistency.
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Brush on the slurry coat and work well into the stone. Allow to tack dry before
applying second and third slightly thicker coats.
Repair mortar should be as dry as possible. Repair mortar to be applied using
small trowels and spatulas to a depth of no more than 12mm per application.
Repairs to be tended between applications, and each stage allowed to go
off to a leathery consistency but still green before application of the next coat
Repairs to be tapped by hand to establish any areas of failure. Each stage
must be sound before work can continue.
Repairs to be kept damp and protected from frost, wind and direct sunlight
to prevent rapid drying out and subsequent cracking, shrinking, and failure.
Use damp hessian as protection. Particular attention needs to be paid to
overnight protection.
Modelling, finish and texture of repairs: care to be taken over final tending
and finishing off. Texture repairs to match adjacent stonework by working
over with hessian, spatulas, plaster modelling and sculpture tools to the
approval of the Architect.
Redundant
fittings/fixtures
Remove all redundant fixtures and fixings and make good with lime mortar
unless otherwise specified. Minimize disturbance to surrounding surfaces.
Where identified, fill hole with lime mortar; for apertures larger than 50x50mm
piece in stone to match adjacent.
Repointing
Mortar Mixes Shall be generally 1:2.5 lime: sand or stonedust as specified. Pozzolanic
materials are to be used where specified. Other specifications of mortars
are to be used where specified.
For ashlar pointing and bedding use 1:3 mix.
Lime To be St Astier NHL 3.5 Hydraulic Lime (NHL 5 for copings or other exposed
locations and NHL 2.0 for ashlar walling and dressings or repair mortar slurry
coat).
Sand Shall be washed coarse, sharp sand from a local source approved by
Architect, complying with the relevant provisions of BS1199.
Aggregate must be added to the sand to improve match with the existing
material. Aggregate may be obtained from natural sands, gravels, brick,
shells, chalk or flint as appropriate. Existing original mortars are to be crushed
and examined to check contents of original aggregate and are to be
matched as much as possible.
Water Water must be clean, fresh and from the piped main.
Mixing Mortar must be carefully batched, gauged and mixed in accordance with
best current practice. Additives shall not be used. Whenever possible
coarse stuff must be left for minimum 24 hours before gauging with cement.
Mixing shall preferably be carried out by one man to produce consistent
results.
Lime putty should be made and stored in the traditional way and left for a
minimum of 24 hours to fatten up.
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All bricks shall be well buttered with mortar before being laid with all joints
flushed up as the work proceeds. Bricks with frogs to be laid frog up.
Facework shall be kept perfectly clean and no rubbing down will be
allowed.
Adverse
weather
Do not bed masonry units or repoint in air temperatures:
• In cement gauged mortars when at or below 3°C and falling or unless
it is at least 1°C and rising (unless mortar has a temperature of not less
than 4°C when laid and the masonry is thoroughly protected)
• In hydraulic lime:sand mortars when at or below 5°C and falling or
unless it is at least 3°C and rising
• In nonhydraulic lime:sand mortars in cold weather without approval
Temperature of the work: Maintain above freezing until mortar has fully set.
Rain and snow: Protect masonry by covering during precipitation and at all
times when work is not proceeding.
Hot conditions and drying winds: Prevent masonry from drying out too rapidly.
Newly placed or pointed work shall be protected where necessary from
damage by night frost and drying effects of sun and wind with sacking or
canvas frames applied to wall surfaces. Protect all newly repaired/erected
work from inclement weather for minimum of seven days after completion.
New mortar damaged by frost: Rake out and replace.
Trial Areas Allow for trial areas of repointing for the Architect’s approval before
general repointing work proceeds.
Biocide for
Vegetable
Growth
Brush off all loose moss and lichen growth and apply Murasol 20 by
Cementone Beaver, or equal approved, in accordance with the
manufacturer’s instructions. Allow minimum 48 hours between completion
of treatment and repointing.
Masonry joint
treatment
Carefully rake out loose and open joints to a sound surface backing (twice
the thickness of the joint but minimum depth of 35 mm), wet and repoint using
a 1:3 lime:sand or stone dust as specified. Joints to be flush but feather edging
of mortar must be avoided by recessing the joint slightly as necessary. Finish
joints flush with a rag, stick or brush.
For wide joints with coarse aggregate mortar the joints should be stippled with
a bristle brush to roughen the surface and tighten the joints.
Finish joints ensuring consistency of colour, texture, profile, and overall
appearance to match the existing surrounding mortar.
Set joint face flush with the face of stonework unless:
• this is at difference with the existing surrounding mortar, and/or
• the joints are very wide or arises are broken; and/or
• the Architect instructs otherwise.
Where masonry arises are eroded, set joint face further back, but avoiding
the creation of ledges, which may trap or hold water.
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Grouting of
Voids in Existing
Structures
Grout mixes may contain constituents from the following list and mix designs
will be agreed on site:
Water, fine sand, lime, pulverised fuel ash (PFA), polyester resin.
Minor grouting operations of surface fractures, cracks and minor voids will
usually be carried out using traditional hand/gravity methods. More detailed
guidance is available from the Architect.
Where larger scale grouting operations are specified the Contractor shall
engage a suitable specialist subcontractor experienced in the type of work
to be undertaken. The specialist subcontractor will be required to make
detailed proposals for the materials, technique and procedures to be used
in the grouting operations for the design team’s approval. The Contractor
must consult his subcontractor before submitting his tender and shall include
a statement of method of grouting, proposed to be adopted, with his tender.
The tender price for grouting must clearly show the breakdown of cost
between the specialist’s price and the main Contractor’s work in connection
with grouting, attendance etc.
In all grouting operations there will be the following general requirements:
a) Provide constant supervision and monitoring for leaks of water and grout,
structural movement etc. Provide all temporary works.
b) Keep accurate records showing volumes, mixes and pressures of water
and grout used at each injection point. Copies of these records to be
provided for the Architect and Engineer as soon as possible after each
section of grouting.
c) Allow for all building work and materials in connection with preparation for
grouting and making good wall faces after and for cleaning off all grout
stains etc. In gravity grouting operations allow for raising all materials to
suitable level above grouting injection points.
d) Flush out with clean water to remove loose material and thoroughly wet
voids.
e) Ensure that 100% grouting is being achieved by constantly checking results
and regrouting as necessary.
SCAFFOLDER
Health & Safety Contractors must comply with the Health and Safety at Work etc Act 1974,
the Management of Health and Safety at Work Regulations 1999, the Work
at Height Regulations 2005 and the Construction (Design and
Management) (CDM) Regulations 2015. Access and working scaffolds
should be designed, constructed and used in accordance with BS EN
12811-1 Temporary works equipment. Scaffolds. Performance requirements
and general design. Method statements, where required, from the
scaffolding subcontractor for the purpose of the Construction Phase Plan
should be submitted to the Principal Contractor, well in advance of the
commencement date. No change from an approved method should be
permitted without a written agreement clearly stipulating the changes. The
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Principal Contractor is responsible for safety standards during erecting and
dismantling of scaffolds.
Structural
Requirements
To comply with the Working at Height regulations 2005, all scaffolds must
be assembled to NASC Technical Guidance TG20:13 Good Practice
Guidance for Tube and Fitting Scaffolding or be designed by bespoke
calculation, by a competent person to ensure it will have adequate
strength rigidity and stability while it is erected , used and dismantled. All
scaffold designs must be engineered in accordance with the most up to
date British Standards, Codes of Practice and other guidance notes.
Temporary Roofs
& Sheeting
Temporary roofs should be designed to resist wind uplift forces. Their
supporting structure will therefore have to be held down. It is essential to
ensure that where holding force is derived from kentledge, anchors or
connections to a sufficient mass of masonry, the holding devices and
connections to them are in place and effective before roofing sheets and
site sheets, if used, are installed. Use of water filled drums for kentledge
should be avoided due to possible leakage, freezing or vandalism. Roof
coverings should generally be new galvanise steel corrugated sheeting,
fixed with special clips to avoid drilling through tops of corrugation. Include
adequate method of disposal of rainwater from temporary roofs. Sheeting
to be 2500mm high solid boarding with entrance gates as necessary,
painted in colour to be agreed with the Architect.
Fixings & Ties Fixings and ties are not allowed except with the express approval of the
Employer and the Architect. Where metal sockets are agreed and left for
future maintenance, they must be of stainless steel, grade 304 or other non-
ferrous material.
Subcontractor’s
Design
It will be the overall responsibility of the Principal Contractor to plan, manage,
monitor and co-ordinate health and safety during construction. Allow for fire
precautions, security, access, safety areas, buttressing, lighting protection etc
together with criteria common to all designs such as design wind speed and
snow loading.
The Principal Contractor will be responsible for ascertaining the requirements
of all sub-contractors including the use of each platform, the number to be
fully boarded, those to be fully boarded, those to be sheeted, location and
purpose of hoists, fans, hoardings, loading bases and the length of time it will
be in position, together with other relevant information.
The Principal Contractor be responsible for obtaining a documented design
with calculations for the erection, use and dismantling of the scaffold
structure and for the integration of these activities within the overall work
programme. It is the duty of the Principal Contractor to check the design.
The Principal Contractor is to submit details of the following, when requested
to do so:
a) design
b) full set of drawings
c) calculations
d) number and location of working levels
e) loading bays
f) manufacturer’s details for specialist equipment such as ladder beams etc.
g) method statement covering erection, use and dismantling.
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In certain cases, before work starts, there will be an independent check by a
competent person.
Control of Work
on Site
Notwithstanding the overall responsibilities of the Principal Contractor for
site activities and health and safety, adequate supervision must be
provided by the scaffolding subcontractor at all times during erection and
dismantling of scaffolding and temporary structures. All scaffolds and
structures should be inspected at least every seven days (and after
weather conditions likely to have affected their strength or stability) by a
competent person. Records of such inspections together with necessary
action must be made and signed by the person making the inspection. No
alterations must be made at any time without written authority from the
Architect. Any proposed modification or alteration that takes a scaffold
outside the scope of a generally recognised standard configuration should
be designed by a competent person and proven by calculation. At all
times during erection, dismantling or alteration to scaffold structures,
access to the working areas needs to be clearly defined by suitable barriers
and notices. Notices warning ‘incomplete scaffold’ should be secured as
necessary in an appropriate place. Stop all work on external scaffolding
during a thunderstorm.
Ensure that the scaffold is erected early enough and/or dismantled late
enough and has sufficient boards in place to suit the programmes of all
subcontractors and the Architect’s inspection programme.
Historic Buildings The Principal Contractor is to alert the scaffolding subcontractor that the
building is of historic importance and any damage whatsoever is
unacceptable. Extreme care is to be taken during erection and
dismantling and the work is to be supervised by a competent person.
Protection Tubes bearing on masonry should be provided with suitable timber bearers.
Against leadwork, felt or other material suitable packing should be used
between the timber and leadwork. Scaffold tube ends which are likely to
come into contact with the fabric of the building during erection,
dismantling or as a consequence of lateral movement should be provided
with plastic end caps. All putlogs to be kept at least 50mm away from the
building and fitted with plastic end caps. All scaffolding and temporary
structures must be adequately earthed against lightning strikes.
All scaffolding and temporary structures must be adequately earthed against
lightning strikes.
Public Access During erection, modification or dismantling, care must be taken to exclude
the public from a clearly defined area around the work. Authorised access
thoroughfares must have effective protection in the form of fans, netting,
sheetings, brickguards etc to protect persons from falling objects.
Ladders and tower scaffolds must not be left unattended when accessible
to the public.
Ladders at ground floor level and other risk areas and tower scaffolds must
be removed and securely locked away at the end of each working day.
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SCHEDULE OF WORKS
ITEM DESCRIPTION COST (£)
1.0 General Notes
1.1 Brief History
The following is an excerpt from Appendix 3, The York Glaziers Trust
Report and Condition Advice 2017:
Browne’s Hospital in Broad Street, Stamford, was founded by William
Browne, merchant of the Calais Staple, and his wife Margaret, for the
relief of 12 paupers of the town. The buildings were completed by 1475,
and extensively restored in 1870. After William and Margaret’s deaths in
1489, the management of the hospital passed to Margaret’s brother,
Thomas Stokke, canon of York and rector of nearby Easton-on-the-Hill.
New letters patent were issued, and the chapel was dedicated on 22
December 1494. Statutes for the management of the institution were
issued on 9 October 1495. Stokke gifted to the hospital its silver seal,
which bears his arms. Thomas Stokke’s rebus of a stork on its nest with
the inscription /+ me sped(e)/ appears in the stained glass of the
Chapel, the Entrance Passage and in the Audit Room.
The medieval stained glass is located in two windows in the south wall
of the Chapel (sII and sIII), in a single window in the Entrance Passage
(west window) and in three windows in the first floor Audit Room (nII, sII,
sIII). The glass has been the subject of two scholarly publications, which
have established its high historical and iconographical significance. The
chapel glazing has been dated to c.1475, with the glazing of the Audit
Room and Entrance Passage to the years after 1489.
By 1822 the glass throughout the Hospital was in a very poor state of
repair. It was restored in 1869, when some new glass was supplied (eg
chapel sII, panel 2c and Audit Room sIV). The glass was cleaned,
releaded and rearranged by G. King & Sons in 1967, with art historical
advice from Dr P A Newton and financial support from the Pilgrim Trust.
Overview of condition
The stained glass is structurally sound and in a stable condition.
However, deterioration due to environmental moisture is evident in the
form of widespread internal microcracking and discolouration of
glasses, pitting of the glass surfaces, and loss of fired paint pigment.
The stained glass in the Chapel and Audit Room is currently protected
by external wire guards, which are in good condition. The Entrance
Passage window has no external protection.
1.2 The glazier undertaking the specified works is to be ICON accredited to
the appropriate level for work on 15th-century stained glass. The glazier
is to provide with their tender a profile of the studio, which should
include details of all the team members who will be carrying out the
works including their level of experience, skills and accreditation.
1.3 Sub-contracting any part of the glazing package of works to another
specialist glazing studio is not permitted.
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1.4 All aspects of the work to the stained glass should follow the CVMA
guidelines for conservation.
1.5 The glazing contractor is to provide a perimeter pointing sample for the
Architect’s consideration and approval prior to repointing the glazing
panels. The pointing sample is to be prepared to a 1000mm long section
internally and externally and is to be carried out in the approved
hydraulic lime mortar mix. Subject to the Architect’s approval, the
pointing sample may be retained as part of the works. Allow to rake out
as necessary.
The perimeter pointing to the glazing can be carried out by either a
skilled mason or the glazing contractor. Any more extensive perimeter
pointing and flaunching required is to be carried out by a skilled mason.
1.6 The desired goals of the project are:
• The documentation and recording of the stained glass and
conservation materials and procedures
• The cleaning of both sides of the stained glass in a conservative
manner so as not to damage or lose the existing painted detail
• The stabilization of the stained glass panels, retaining the existing
lead work
• Improvements to the appearance by the reduction of mending
leads
• The environmental protection of the stained glass through the
construction of a purpose-made bronze frame with support bars
• The in-situ cleaning of the existing diamond quarry glazing
accessible during the conservation and environmental
protection works
1.7 It is crucial that the proposals are addressed on a window by window basis
to limit the impact of the EPG. Exactly how the impact of the EPG is
mitigated is for the selected glass conservators to work up during the
tender process. The overall view of the south elevation of the Hospital from
Broad Street, and internal views of the windows in the chapel and the
Audit room will also be important considerations for the glass conservator
in the details of the final proposals.
It is intended that the glass conservator will include their own thoughts and
proposals on detailing and positioning of the EPG with their tender return.
1.8 Documentation and recording required and produced should broadly
follow the Guidelines of The Churches Building Council:
https://www.churchofengland.org/sites/default/files/2018-
12/CCB_Conservation-reports.pdf
2.0 General Preliminaries
2.1 Allow for all preliminaries, access equipment, temporary works and
protection.
2.2 Protect all parts of the existing fabric of the building from damage
during the works. Minimise dust and noise during the works. Clear away
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debris and surplus materials as it accumulates. Specifically protect
adjacent windows and historic joinery.
2.3 Comply with all CDM regulations. Develop the Health & Safety plan and
compile a Health & Safety File.
2.4 Keep the site safe and secure during the works and out of hours. Stored
materials should be secured out of hours.
2.5 Electricity and water are available on site. Maintain, alter and adapt
temporary works as necessary. The contractor should provide suitable
on site welfare facilities.
The client is willing for contractors to use a wc and kitchenette within
the Hospital, to be designated for their sole use during the works.
2.6 Minimise dust and noise during the works.
2.7 The site is to be a no smoking and no radios site.
2.8 Great care must be taken to keep roads and paths safe and clean of
debris. Contractor parking, deliveries to site, plant and the storage of
materials must be carefully considered in relation to other road and
path users and suitable allowances made.
There is no onsite parking. Some parking spaces may be able to be
coned off roadside at the front of the building with agreement from the
County Council.
2.9 All proprietary products and materials to be employed in accordance
with the manufacturer’s recommendations, codes of practice, etc and
good conservation practice.
2.10 Read the architect’s specification and drawings together and allow for
all parts of the work shown and described.
2.11 Liaise with the Curator over keys, times of working, cleaning up for
services, access, location of welfare facilities etc.
2.12 Following completion of the works the contractor must ensure that road
ways and paths are returned to the condition they were in prior to the
work commencing. Leave the works clean and tidy on completion.
2.13 Prior to commencement of the works undertake dilapidation
photographs, cross referenced to the plan and issue to the Architect
and Client electronically via USB stick each.
2.14 Labour
The Contractor shall insert hourly rates and/or percentages as below
and shall include the total within the tender sum. The inserted rates and
percentages shall remain fixed for the duration of the contract.
A. Building labour (unskilled) 5 x £ _________ =
B. Building labour (skilled) 5 x £ _________ =
Note: The Contractor must complete both (A) & (B) above.
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2.15 Material & Goods
C. Include the sum of £100 for materials and goods.
D. Add % for incidental costs, overheads and profit _______%.
2.16 Rates (do not include within tender sum)
Indicate here for Main Contractor’s % rate for profit and attendance on
sub-contractors __________%.
Indicate extra over cost for lime repointing of 1m length £________ __.
2.17 Contingencies
Allow a provisional sum of £5,000 for contingencies, to be expended at
the direction of the Architect.
£5,000.00
3.0 Scaffolding
3.1 Erect and maintain access scaffolding necessary to complete the
specified works to undertake sizes and templates, removal of wire
guards, removal of panels, installation of protective glazing, cleaning of
plain glazing, reinstallation of wire guards and reinstallation of stained
glass. To be in accordance with the requirements set out within the
Project Preliminaries, current Health & Safety and British Standards.
3.2 For any areas of permanent external scaffolding where required,
provide new 3 metre high metal sheet fencing to bottom of each fixed
scaffold to enclose the working area, provided with a secure access
door which is to be locked at the end of each working day.
Contractor to supply a scaffolding alarm system for any permanent
scaffolding, with telephone call out to suit client requirements.
3.3 Indicate here weekly hire cost for scaffolding if contract period is
extended £______ ____ (do not include within tender sum).
4.0 Chapel windows sII and sIII
4.1 All works items are to be in accordance with Specification Leaded Light
Glazing trade clauses.
4.2 Issues and constraints
The majority of the stained glass is in Chapel window sII. There is limited
stained glass in the tracery only of sIII.
The clear leaded light quarries to sIII are to be left insitu. The external
wire guards are in good condition and are to be retained.
The glazing conservator is to mitigate the impact of the EPG through
considering the type of glass, leading pattern design, method of
framing and positioning of the EPG and the original window.
The EPG for the stained glass in sII needs to be considered in conjunction
with the clear leaded light window of sIII in terms of internal and external
views and positioning of the EPG. Following discussions with Historic
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England’s specialist advisor, consideration is to be given to installing the
stained glass framed panels of sII on the same line as the existing clear
glazing of sIII with the new outer protective glazing to sII to be fitted
between the stained glass line and the external window guard line. See
sketch diagram 1924/104. Careful consideration to be given to
potential fixing methods for the EPG if not using the existing glazing
groove.
Standard tender to be returned on that basis.
Alternative tender price to be submitted with tender return if glazing
conservator wishes to propose an alternative approach.
See photos 01-08.
4.3 Undertake in-situ photographic record and inspection of glazing, take
sizes and templates.
4.4 Provisionally allow to produce mock up of potential solution(s) to be set
up and viewed and agreed with all key stakeholders on site before full
fabrication – read with 4.3 below.
4.5 Fabricate new code 5 lead condensation trays and outer protective
glazing as Specification.
Following discussions with Historic England’s specialist advisor,
consideration to be given to providing outer protected glazing as
diamond quarry glazing, reflecting the largely diamond quarry glazing
to window sIII and to historic buildings on other side of Broad Street.
Standard tender to be returned on that basis.
Alternative tender price to be submitted with tender return if glazing
conservator wishes to propose an alternative approach.
4.6 Return to site to temporarily remove existing wire guards, remove
stained glass panels, install lead condensation trays and new outer
protective glazing, and reinstall wire guards externally, renewing fixings
with stainless steel clips and screws as may be necessary.
4.7 Clean diamond quarry glazing to window sIII in-situ.
4.8 Undertake studio works to stained glass: recording, leading, glass repairs
and cleaning, all as Specification.
4.9 Frame stained glass panels as Specification.
4.10 Return to site and reinstall framed stained glass.
4.11 Supply copies of all in-situ, pre and post conservation documentation
and photographic records to client and architect.
4.12 Masonry repairs
Allow provisional sum of £1000 to undertake minor areas of lime mortar
consolidation repair of window stonework. To be agreed on site once
scaffold is in place.
£1,000.00
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5.0 Audit Room windows sII, sIII, sIV
5.1 All works items are to be in accordance with Specification Leaded Light
Glazing trade clauses.
5.2 Issues and constraints
The medieval stained glass in the Audit Room is located in the upper
sections of each window.
The lower sections are modern clear leaded light diamond quarries
which are to be left insitu. There are opening casements in the lower
right plain glazed section of Audit Room windows sII and sIV.
The external wire guards are in good condition and are to be retained.
The glazing conservator is to mitigate the impact of the EPG through
considering the type of glass, leading pattern design, method of
framing and positioning of the EPG and the original window.
The EPG for the stained glass to Audit Room windows sII, sIII, sIV needs
to be considered in conjunction with Chapel windows of sII and sIII in
terms of overall external views and positioning of the EPG. Following
discussions with Historic England’s specialist advisor, consideration is to
be given to installing the stained glass framed panels on the same line
as existing, to maintain a continuous glazing line viewed internally with
the quarry glazing below, with the new outer protective glazing to be
fitted between the stained glass line and the external window guard
line. See sketch diagram 1924/104. Careful consideration to be given to
potential fixing methods for the EPG if not using the existing glazing
groove.
Standard tender to be returned on that basis.
Alternative tender price to be submitted with tender return if glazing
conservator wishes to propose an alternative approach.
See photos 09-14.
5.3 Undertake in-situ photographic record and inspection of glazing, take
sizes and templates.
5.4 Provisionally allow to produce mock up of potential solution(s) to be set
up and viewed and agreed with all key stakeholders on site before full
fabrication – read with 4.2, 4.3 and 5.3 below.
5.5 Fabricate new code 5 lead condensation trays and outer protective
glazing as Specification.
Following discussions with Historic England’s specialist advisor,
consideration to be given to providing outer protected glazing as
diamond quarry glazing, reflecting the diamond quarry glazing to the
lower window sections and to historic buildings on other side of Broad
Street.
Standard tender to be returned on that basis.
Alternative tender price to be submitted with tender return if glazing
conservator wishes to propose an alternative approach.
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5.6 Return to site to temporarily remove existing wire guards, remove
stained glass panels, install lead condensation trays and new outer
protective glazing, and reinstall wire guards externally, renewing fixings
with stainless steel clips and screws as may be necessary.
5.7 Clean diamond quarry glazing to all windows in-situ.
Ease opening lights and ensure they are left in working order.
5.8 Undertake studio works to stained glass: recording, leading, glass repairs
and cleaning, all as Specification.
5.9 Frame stained glass panels as Specification.
5.10 Return to site and reinstall framed stained glass.
5.11 Supply copies of all in-situ, pre and post conservation documentation
and photographic records to client and architect.
5.12 Masonry repairs
Allow provisional sum of £1500 to undertake minor areas of lime mortar
consolidation repair and pinning of fractured window stonework. To be
agreed on site once scaffold is in place.
£1,500.00
6.0 Audit Room window nII
6.1 All works items are to be in accordance with Specification Leaded Light
Glazing trade clauses.
6.2 Issues and constraints
The medieval stained glass in Audit Room nII is located in the tracery
section A1 only.
The remaining lower sections are modern clear leaded light diamond
quarries which are to be left insitu. There is an opening casement in the
lower right plain glazed section.
The external wire guards are in good condition and are to be retained.
The glazing conservator is to mitigate the impact of the EPG through
considering the type of glass, leading pattern design, method of
framing and positioning of the EPG and the original tracery glazing.
See photo 15.
6.3 Undertake in-situ photographic record and inspection of glazing, take
sizes and template for tracery section A1.
6.4 Fabricate new outer protective glazing for tracery section A1 as
Specification.
6.5 Return to site to temporarily remove existing wire guards, remove
tracery section A1, install new outer protective glazing, and reinstall wire
guards externally, renewing fixings with stainless steel clips and screws
as may be necessary.
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6.6 Clean diamond quarry glazing in-situ.
Ease opening light and ensure it is left in working order.
6.7 Undertake studio works: recording, leading, glass repairs and cleaning
of tracery section A1.
6.8 Frame tracery section A1 as Specification.
6.9 Return to site and reinstall framed tracery section A1.
6.10 Supply copies of all in-situ, pre and post conservation documentation
and photographic records to client and architect.
7.0 Entrance Passage window (un-numbered – EPW)
7.1 All works items are to be in accordance with Specification Leaded Light
Glazing trade clauses.
7.2 Issues and constraints
The medieval stained glass in the Entrance Passge is in the middle two
of the four main lights, and in all four tracery sections.
The sections of clear leaded light diamond quarries are to be left insitu.
The Entrance Passage window has no external protection.
The glazing conservator is to mitigate the impact of the EPG through
considering the type of glass, leading pattern design, method of
framing and positioning of the EPG and the original window.
The EPG for the Entrance Passage window needs to be considered in
conjunction with the clear leaded light glazing sections in terms of
overall external views and positioning of the EPG. Following discussions
with Historic England’s specialist advisor, consideration is to be given to
installing the stained glass framed panels on the same line as existing,
to maintain a continuous glazing line viewed internally with the quarry
glazing, with the new outer protective glazing to be fitted between the
stained glass line and the external window guard line. See sketch
diagram 1924/104. Careful consideration to be given to potential fixing
methods for the EPG if not using the existing glazing groove.
Standard tender to be returned on that basis.
Alternative tender price to be submitted with tender return if glazing
conservator wishes to propose an alternative approach.
See photos 16-19.
7.3 Undertake in-situ photographic record and inspection of glazing, take
sizes and templates.
7.4 Fabricate new code 5 lead condensation trays and outer protective
glazing as Specification.
Following discussions with Historic England’s specialist advisor,
consideration to be given to providing outer protected glazing as
diamond quarry glazing, reflecting the diamond quarry glazing to the
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lower window sections and to historic buildings on other side of Broad
Street.
Standard tender to be returned on that basis.
Alternative tender price to be submitted with tender return if glazing
conservator wishes to propose an alternative approach.
7.5 Return to site to remove stained glass panels, install lead condensation
trays and new outer protective glazing.
7.6 Provide new external window guards to all lights.
Type/material: Stainless steel wire guards (as approved by Historic
England)
Size/gauge: 12 gauge with a 75mm (vertical) x 12mm (horizontal) pitch
with a 6mm frame all round.
Finish: Powder coated black.
Fixing: Black powder coated stainless steel clips fixed into mortar joints with
black coated / Japanned stainless steel screws.
Other requirements: Protections to be located between mullions / tracery
ie. to each bay, not in front of frame.
Provide a sample panel for Architect's approval prior to works
commencing on site, if approved this may be incorporated as part of the
works.
7.7 Clean diamond quarry glazing in-situ.
7.8 Undertake studio works to stained glass: recording, leading, glass repairs
and cleaning, all as Specification.
7.9 Frame stained glass panels as Specification.
7.10 Return to site and reinstall framed stained glass.
7.11 Supply copies of all in-situ, pre and post conservation documentation
and photographic records to client and architect.
7.12 Masonry repairs
Allow provisional sum of £500 to undertake minor areas of lime mortar
consolidation repair of window stonework. To be agreed on site once
scaffold is in place.
£500.00
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COLLECTION PAGE
COST (£)
1.0 General Notes
2.0 General Preliminaries
3.0 Scaffolding
4.0 Chapel windows sII and sIII
5.0 Audit Room windows sII, sIII, sIV
6.0 Audit Room window nII
7.0 Entrance Passage window
8.0 Other Preliminaries not included in Schedule of Works
9.0 Profit and Attendance
10.0 Any works not included in items above
Total of Tender (excluding VAT)
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APPENDIX 1: PHOTOGRAPHS
Photo 1: internal view of Chapel window sII and
part of sIII
Photo 2: Chapel window sIII stained glass tracery
Photo 3: Chapel window sII upper section Photo 4: Chapel window sII lower section
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Photo 5: Chapel window sIII tracery stained glass
Photo 6: Chapel window sII external with guards Photo 7: Chapel window sII external close up
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Photo 8: internal view of Stained glass to Chapel sII
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Photo 9: overall view of Audit Room windows sII, sIII, sIV
Photo 10: Audit Room window sII – 2a, 2b and A1
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Photo 11: Audit Room window sIII – 2a, 2b and A1
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Photo 12: Audit Room window sIV – 2a, 2b and A1
Photo 13: Plastic Masonry repairs needed to Audit Room Photo 14: Pinned Masonry repairs needed to Audit Room
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Photo 15: Audit Room nII – A1
Photo 16: Entrance Passage – extent of stained glass
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Photo 17: Entrance Passage – tracery detail
Photo 18: Entrance Passage window side-on view Photo 19: Entrance Passage – detail of mullion and cill
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Photo 20: Hospital viewed along Broad St from the west Photo 21: Hospital viewed along Broad St from the east
Photo 22: Hospital viewed across Broad St from the south
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APPENDIX 2: CVMA NUMBERING SYSTEM
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APPENDIX 3: LIST OF ABBREVIATIONS TO BE USED ON STAINED GLASS DIAGRAMS
Cracks Indicate with dotted lines used in conjunction with M, Pi, Po, or Ps to denote
application
Ea Edge joined by adhesive – specify in written record
Eb Edge joined by copper foil
L Leaf lead or strap lead
F Artificial filling – specify in written record
P Previous repairs or insertions
Gr Glass installed reversed – specify in written record if previous or new
Gu Re-used glass newly inserted (state source if known)
T Pieces transferred within panel or window (state previous location)
M Modern glass newly inserted
Pi Plated on front (inside)
Po Plated on back (outside)
Ps Plated on both sides
If plating is tinted or coloured, ‘t’ may be added
A New paint pigments (fired)
New painted areas are only permitted on plating or new glass.
Pc Paint consolidation – specify in written record
Please add other symbols if necessary, for individual projects.
Note
Submitted diagrams must be printed large enough to enable them to read easily.
The purpose of this diagram is to provide factual information on work included in the current
programme of conservation, rather than an assessment of the date of every piece of glass in
the window. Art historical observations that can be gained only whilst the glass is on the
bench should nevertheless be recorded.
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APPENDIX 4: FORM OF TENDER
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FORM OF TENDER
Project: 1924 Browne’s Hospital: Stained Glass Conservation
This tender is to be delivered to the office of Stephanie Norris Architects Ltd within a sealed
envelope and must arrive by 4pm on XXXX August 2020.
Facsimile copies will not be accepted.
I/We having read the Conditions Of Contract, Specification and drawings delivered to us and
having visited the site and inspected the proposed works, do hereby offer to execute the
whole of the works in accordance with those Documents including Provisional Sums and
Contingencies for the sum of:
______________________________________________________________________________
__________________________________________ (£ p) exclusive of VAT
I/We undertake, in the event of your acceptance, to execute with your client a form of
contract embodying all the conditions and terms contained in the offer to the reasonable
satisfaction of the Architects: Stephanie Norris Architects Ltd, 8 The Coppice, Impington
Cambridge CB24 9PP
I/We agree that should obvious errors in pricing or arithmetical errors be discovered in the
specification submitted by me/us before acceptance of this offer, that these errors will be
dealt with in accordance with the Alternative 1, contained in Section 6 of the NJCC ‘Code of
Procedure for Single Stage Selective Tendering’ 1996.
I/We understand that I am/we are tendering at my/our expense and that neither the lowest,
nor any other tender will necessarily be accepted.
Alternative contract period if requested in the Specification: ______________________________
Alternative start date if requested in the Specification: ___________________________________
Date this _____________________ day of _______________________________ 20__________
Signed: ______________________________________ Role in Company: ___________________
For and on behalf of: ______________________________________________________________
Address: _______________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
Telephone No: _____________________________ Fax No: _____________________________
E-mail Address: _________________________________________________________________