building regulations j: combustion appliances and fuel storage systems 2013

8/10/2019 Building Regulations J: Combustion Appliances and Fuel Storage Systems 2013

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MAIN CHANGES MADE BY THE

2010 AMENDMENTS

This 2010 edition, incorporating the further 2010amendments reflects the changes made as a resultof the Building Regulations 2010 and Building(Approved inspector etc) Regulations 2010. Thechanges mainly reflect regulation number changesas a result of re-ordering. There have been noamendments to the substantive requirementsin Schedule 1 (i.e. Parts A to P) of the BuildingRegulations.

Please note the simplification of the definition ofroom for residential purposes in regulation 2 ofthe Building Regulations 2010. Please also notethat L1(c) has now become regulation 40.

MAIN CHANGES IN THE

2004 EDITION

Section 1

New guidance has been included for access forvisual inspection of concealed flues. This shouldensure that flues can be properly inspected both

when an appliance is first commissioned andsubsequently serviced.

Section 2

Guidance has been included in support of a newrequirement J3 Warning of release of carbonmonoxide on the provision of carbon monoxidealarms where solid fuel appliances are installed.

The provisions for flue outlet clearances relativeto adjacent pitched roofs have been clarified inDiagram 17.

The guidance on the provision of hearths and

wall clearances for solid fuel appliances havebeen made more flexible to take account of theavailability of modern appliances.

Section 2, 3 & 4

The guidance for permanent ventilation openingsfor open flued appliances in very airtight houses(those with a design air permeability less than orequal to 5.0 m3/(h.m2)) have been increased tocounteract the decrease in adventitious ventilationrelative to older houses. Appendix F gives adviceon assessing the air permeability of older housesin relation to this guidance.

Section 4

This section now explicitly includes liquid biofueland blends on mineral oil and liquid biofuelwithin the scope of combustion installationsdesigned to burn oil.

Section 5

The guidance on identifying where secondarycontainment for oil tanks is necessary has beenexpanded to include locations in inner protectionzone as shown on the Environment Agencysgroundwater sources map.

Appendix G

This informative appendix provides and explanationof the European designation system for certain flueand chimney products.


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Approved Document J Combustion appliances and fuel storage systems

Contents

PAGE

What is an Approved Document? 3

How to use this Approved Document 3

Where you can get further help 3Responsibility for compliance 4

The requirements 5

Limitation on requirements 5

Types of building work covered by thisApproved Document 5

Notification of work 6

Exemptions 6

Materials and workmanship 7

Supplementary guidance 7Technical Specifications 7

Independent schemes of certificationand accreditation 7

Interaction with other legislation 7

Maintenance 8

The Requirements J1, J2, J3, J4, J5,J6 and J7 9

Section 0: General guidance 10

Introduction to the provisions 10Explanation of terms used 10

Measuring the size of flues and ducts 16

Section 1: Provisions which applygenerally to combustion installations 17

Performance 17

Air supply for combustion appliances 17

Permanently open ventilation of rooms 17

Permanent ventilation of appliancecompartments 17

Ventilation of other rooms or spaces 17

Permanently open air vents 19

Provisions complying with both Part Fand Part J 20

Interaction of mechanical extractventilation and open-flued combustionappliances 21

Provision of flues 22

Condensates in flues 22

Construction of masonry chimneys 22

Construction of flueblock chimneys 22

Material change of use 23

PAGE

Connecting flue pipes 23

Repair of flues 23

Re-Use of existing flues 24

Use of flexible metal flue liners for therelining of chimneys 24

Use of plastic fluepipe systems 24

Factory-made metal chimneys 24

Concealed flues 25

Configuration of natural draught fluesserving open-flued appliances 26

Inspection and cleaning openings in flues 27

Flues discharging at low level nearboundaries 27

Dry lining around fireplace openings 27

Condition of combustion installationsat completion 27

Notice Plates for hearths and flues 28

Access to combustion appliances formaintenance 28

Section 2: Additional provisions forappliances burning solid fuel (includingsolid biofuel) with a rated output upto 50kW 29

Air supply to appliances 29

Size of flues 29

Height of flues 30

Outlets from flues 30

Connecting fluepipes 32

Location and shielding of connectingfluepipes 32

Debris collecting space 33

Masonry and flueblock chimneys 33

Separation of combustible material fromfireplaces and flues 34


Lining and relining of flues in chimneys 34

Formation of gathers 35

Hearths 37

Fireplace recesses and prefabricatedappliance chambers 38

Fireplace lining components 40

Walls adjacent to hearths 40

Alternative approach 40

Carbon monoxide alarms 41

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Combustion appliances and fuel storage systems Approved Document J

PAGE

Section 3: Additional provisions, for gasburning appliances 43

Gas safety (Installation and Use)Regulations 43

Gas fires (other than flueless gas fires) 45

Flueless gas appliances 45

Air supply to gas fires and otherappliances 45

Flued decorative fuel effect (DFE) fires 45

Flued appliances other than decorativefuel effect fires 45

Air supply to flueless appliances 45

Size of natural draught flues for openflued appliances 47

Height of natural draught flues for open

flued appliances 48Outlets from flues 48

Provision of flues 51

Connecting fluepipe components 52

Masonry chimneys 52

Flueblock chimneys 52


Location and shielding of flues 52

Relining of flues in chimneys 52

Debris collection space for chimneys 53Bases for back boilers 53

Hearths 54

Shielding of appliances 54


Section 4: Additional provisions for oilburning appliances 56

Scope 56

Appliances fitted in bathrooms andshower rooms 56

Air supply to appliances 56

Size of flues (other than balanced fluesand flues designed to discharge throughor adjacent to walls) 56

Outlets from flues and flue heights 56

Flues for oil-fired appliances: flue gastemperature 59

Provisions for flue gas temperatures inexcess of 250C 59

Provisions for flue gas temperatures not

exceeding 250C 59Connecting fluepipe components 59

PAGE

Masonry chimneys 60

Flueblock chimneys 60


Location and shielding of flues 60

Relining of flues in chimneys 60Flues for appliances burning Class D oil 61

Hearths for oil-fired appliances 61

Shielding of oil-fired appliances 61


Section 5: Provisions for liquid fuelstorage and supply 63

Performance 63

Heating oil storage installations 63

Protective measures against fire 63Oil supply pipe systems: means ofautomatic isolation 64

Provisions where there is a risk ofoil pollution 64

LPG storage installations 64

Tank location and protective measures 65

Location and support of cylinders 65

LPG pipework (Informative) 67

APPENDICES

Appendix A:Checklist for checkingand testing of hearths, fireplaces, fluesand chimneys 68

Appendix B:Opening areas of large orunusual fireplaces 70

Appendix C:Example calculation of theventilation requirements of a gas firedappliance 71

Appendix D:Example calculation of theventilation requirements of an oil fired

appliance 72

Appendix E:Methods of checkingcompliance with requirement J2 73

Appendix F:Assessing air permeability ofolder dwellings in relation to permanentventilation requirements 76

Appendix G:European chimney designations 77

Appendix H:Addressees 79

Standards referred to 80

Other publications referred to 82

Index 83

J CONTENTS


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This document has been approved and issuedby the Secretary of State to provide practicalguidance on ways of complying with RequirementsJ1 to J7 and regulations 7 of the BuildingRegulations 2010 (SI 2010/2214) for Englandand Wales. The Building Regulations 2010 arereferred to throughout the remainder of thisDocument as the Building Regulations. Whereappropriate the Approved Document also givesguidance on relevant requirements in the Building(Approved Inspectors etc) Regulations 2010(SI 2010/2215).

The intention of issuing Approved Documentsis to provide guidance about compliance withspecific aspects of building regulations in someof the more common building situations. Theyset out what, in ordinary circumstances, may bereasonable provision for compliance with therelevant requirement(s) of building regulations towhich they refer.

If guidance in an Approved Document is followedthere will be a presumption of compliance withthe requirement(s) covered by the guidance.However, this presumption can be overturned,so simply following guidance does not guaranteecompliance. For example, if one particular caseis unusual in some way, then normal guidancemay not be applicable. It is also important to notethat there may well be other ways of achievingcompliance with the requirements. There istherefore no obligation to adopt any particularsolution contained in this Approved Documentif you would prefer to meet the relevantrequirement in some other way. However,persons intending to carry out building workshould always check with their BuildingControl Body, either the local authority oran approved inspector, that their proposalscomply with building regulations.

The guidance contained in this ApprovedDocument relates only to the particularrequirements of building regulations that thedocument addresses (see Requirements below).However, building work may be subject to morethan one requirement of building regulations. Insuch cases the work will also have to complywith any other applicable requirements ofbuilding regulations.

This document is one of a series that has beenapproved and issued by the Secretary of Statefor the purpose of providing practical guidancewith respect to the requirements of Schedule 1and Regulation 7 of the Building Regulations2010 (SI 2010/2215) for England and Wales.

At the back of this document is a list of all thedocuments that have been approved and issuedby the Secretary of State for this purpose.

How to use this Approved

Document

In this document the following conventions havebeen adopted to assist understanding and

interpretation:a. Text shown against a green background are

extracts from the Building Regulations orBuilding (Approved Inspectors etc) Regulations,and set out the legal requirements that relateto compliance with the sanitation, hot watersafety and water efficiency requirements ofbuilding regulations. It should be rememberedhowever that, as noted above, building worksmust comply with all the other applicableprovisions of building regulations.

b. Key terms are defined in Section 0 and areprinted initalic text.

c. Details of technical publications referred to inthe text of this Document will be given infootnotes and repeated as end notes. Areference to a publication is likely to be madefor one of two main reasons. The publicationmay contain additional or more comprehensivetechnical detail, which it would be impracticalto include in full in the Document but which isneeded to fully explain ways of meeting therequirements; or it is a source of more generalinformation. The reason for the reference willbe indicated in each case. The reference willbe to a specified edition of the document.

The Approved Document may be amendedfrom time to time to include new referencesor to refer to revised editions where this aidscompliance.

Where you can get further help

If you do not understand the technical guidanceor other information set out in this ApprovedDocument and the additional detailed technicalreferences to which it directs you, there are anumber of routes through which you can seekfurther assistance:

The Communities and Local Governmentwebsite: www.communities.gov.uk

The Planning Portal website:www.planningportal.gov.uk

If you are the person undertaking the buildingwork you can seek assistance either fromyour local authority building control service orfrom your approved inspector (depending onwhich building control service you are using,or intend to use, to certify compliance of yourwork with the requirements of the BuildingRegulations).

What is an Approved Document? J


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J WHAT IS AN APPROVED DOCUMENT?

Persons registered with a competent personself-certification scheme may be able to gettechnical advice from their scheme operator.

If your query is of a highly technical nature youmay wish to seek the advice of a specialist, orindustry technical body, for the relevant subject.

Responsibility for compliance

It is important to remember that if you are theperson (e.g. designer, builder, installer) carryingout building work to which any requirement ofbuilding regulations applies you have aresponsibility to ensure that the work complieswith any such requirement. The building ownermay also have a responsibility for ensuringcompliance with building regulation requirementsand could be served with an enforcement noticein cases of non-compliance.


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This Approved Document, which takes effecton 1 October 2010, deals with combustionappliances and fuel storage systems in theBuilding Regulations 2010 (as amended).

Limitation on requirementsIn accordance with regulation 8 of the BuildingRegulations, the requirements in Parts A to D, Fto K and N and P (except for paragraphs G2, H2and J6) of Schedule 1 to the Building Regulationsdo not require anything to be done except for thepurpose of securing reasonable standards ofhealth and safety for persons in or aboutbuildings (and any others who may be affectedby buildings or matters connected with buildings).

Paragraph G2 is excluded from regulation 8 as itdeals with the conservation of water. ParagraphsH2 and J6 are excluded from regulation 8

because they deal directly with prevention of thecontamination of water and of oil pollution. PartsE and M (which deal, respectively, with resistanceto the passage of sound and access to and useof buildings) are excluded from regulation 8because they address the welfare andconvenience of building users. Part L is excludedfrom regulation 8 because it addresses theconservation of fuel and power. All these mattersare amongst the purposes, other than health andsafety that may be addressed by BuildingRegulations.

Types of work covered by thisApproved Document

Building work

Building work, as defined in regulation 3 of theBuilding Regulations 2010, includes the erectionand extension of a building, the provision orextension of a controlled service or fitting, andthe material alteration of a building or a controlledservice or fitting. In addition, Building Regulationsmay apply in cases where the purposes for whichor the manner or circumstances in which abuilding or part of a building is used change in

the way that constitutes a material change ofuse. Under regulation 4 of the BuildingRegulations 2010 (as amended), building workshould be carried out in such a way that, oncompletion of work,

i. the building complies with the applicableParts of Schedule 1 to the BuildingRegulations,

ii. in the case of an extension or materialalteration of a building, or the provision,extension or material alteration of a controlledservice or fitting, where it did not comply withany such requirement, it is no moreunsatisfactory in relation to that requirementthan before the work was carried out.

Work described in Part J concerns the provisionor extension of controlled services or fittings.Work associated with installations covered inthese sections may be subject to other relevantParts of the Building Regulations.

Material change of use

A material change of use occurs in specifiedcircumstances in which a building or part of abuilding that was previously used for onepurpose will be used in future for another. Wherethere is a material change of use the BuildingRegulations set requirements that must be metbefore the building can be used for its newpurpose.

Regulation 5 of the Building Regulations specifiesthe following circumstances as material changesof use:

a building is used as a dwelling wherepreviously it was not.

a building contains a flat where previously itdid not.

a building is used as an hotel or boardinghouse where previously it was not.

a building is used as an institution wherepreviously it was not.

a building is used as a public building wherepreviously it was not.

a building no longer comes within the

exemptions in Schedule 2 to the BuildingRegulations where previously it did.

a building which contains at least onedwelling contains a greater or lesser numberof dwellings than it did previously.

a building contains a room for residentialpurposes where previously it did not.

a building which contains at least one room forresidential puposes contains a greater or lessernumber of such rooms than it did previously.

a building is used as a shop where previously

it was not.Parts J1 to J4 will apply to all the materialchanges of use mentioned above which meansthat whenever such changes occur the buildingmust be brought up to the standards required byParts J1 to J4.

Historic buildings

Buildings included in the schedule of monumentsmaintained under section 1 of the AncientMonuments and Archaeological Areas Act 1979are exempt from compliance with the requirementsof the Building Regulations.

The requirements


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J THE REQUIREMENTS

There are other classes of buildings where specialconsideration may be needed in deciding what isadequate provision for compliance with Part J:

a. listed buildings;

b. buildings situated in designatedconservation areas;

c. buildings which are of architectural orhistoric interest and which are referredto as a material consideration in a localauthoritys development plan; and

d. buildings of architectural and historicalinterest within national parks, areas ofoutstanding or natural beauty and worldheritage sites.

It would not normally be considered appropriateto relax the requirements of Part J since theyrelate to health and safety. However, it may benecessary to seek alternative technical solutionsto those set out in this approved document in

order to achieve reasonable standards of safetywithout prejudicing the character of the hostbuilding or increasing the risk of long-termdeterioration of the buildings fabric or fittings.

In determining what is appropriate in thecircumstances, the advice of the local authoritysconservation officer should be sought. Theviews of the conservation officer are particularlyimportant where building work requires planningpermission and/or listed building consent.

Notification of work

In almost all cases of new building work itwill be necessary to notify a Building ControlBody (BCB) in advance of any work starting.There are two exceptions to this: where workis carried out under a self-certification schemelisted in Schedule 3, and where work is listedin Schedule 4 to the Building Regulations asbeing not notifiable.

Competent person self-certification schemesunder Schedule 3

Under regulation 12(6) of the BuildingRegulations it is not necessary to notify a BCBin advance of work which is covered by this

Approved Document if that work is of a typeset out in column 1 of Schedule 3 to theRegulations and is carried out by a personregistered with a relevant self-certification(competent persons) scheme as set out incolumn 2 of that Schedule. In order to joinsuch a scheme a person must demonstratecompetence to carry out the type of work thescheme covers, and also the ability to complywith all relevant requirements in the BuildingRegulations.

There are a number of schemes authorisedfor the installation of combustion appliances.

Details of current schemes including those

relating to combustion appliances canbe found from www.communities.gov.uk/planningandbuildingregulations/competentpersonsschemes. Full details ofthe schemes can be found on the individualscheme websites.

Where work is carried out by a person registeredwith a competent person scheme, regulation20 of the Building Regulations and regulation20(1) of the Building (Approved Inspectors etc.)Regulations 2010 require that the occupier ofthe building be given, within 30 days of thecompletion of the work, a certificate confirmingthat the work complies with all applicableBuilding Regulation requirements. There is a alsorequirement that the BCB be given a notice thatthis has been done, or a copy of the certificate,again within 30 days of the completion of thework. These certificates and notices are usuallymade available through the scheme operator.

BCBs are authorised to accept these certificatesas evidence of compliance with the requirementsof the Building Regulations. However, localauthority inspection and enforcement powersremain unaffected, although they are normallyused only in response to a complaint that workdoes not comply.

Work which is not notifiable underSchedule 4

Schedule 4 to the Building Regulations sets outtypes of work where there is no requirementto notify a BCB that work is to be carried out.These types of work are mainly of a minor nature

where there is no significant risk to health, safety,water efficiency or energy efficiency. Health,safety, and energy efficiency requirementscontinue to apply to these types of work; onlythe need to notify a BCB has been removed.

Where only non-notifiable work as set out inSchedule 4 is carried out, there is no requirementfor a certificate confirming that the workcomplies with Building Regulation requirementsto be given to the occupier or the BCB.

In general, all work on a combustion appliancewhich is not a repair or maintenance will be

notifiable work and Schedule 4 will not apply.However, it might be possible to add a controldevice to the appliance or to alter its electricalconnection under the allowance in this schedule.Local authority building control departments cangive advice in cases of doubt.

Exemptions

Schedule 2 to the Building Regulations setsout a number of classes of buildings whichare exempt from all Building Regulationsrequirements, including those in Part J.


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THE REQUIREMENTS J

Please note that the Gas Safety (Installationand Use) Regulations apply to buildings exemptunder the Building Regulations.

Materials and workmanship

Any building work which is subject to therequirements imposed by Schedule 1 to theBuilding Regulations shall be carried out inaccordance with regulation 7. Guidance onmeeting these requirements on materials andworkmanship is contained in ApprovedDocument 7.

Building Regulations are made for specific purposes,primarily the health and safety, welfare andconvenience of people and for energyconservation. Standards and other technicalspecifications may provide relevant guidance tothe extent that they relate to these considerations.However, they may also address other aspectsof performance or matters which, although theyrelate to health and safety etc., are not coveredby the Building Regulations.

When an Approved Document makes referenceto a named standard, the relevant version of thestandard to which it refers is the one listed at theend of the publication. However, if this versionhas been revised or updated by the issuingstandards body, the new version may be usedas a source of guidance provided it continuesto address the relevant requirements of theRegulations.

Supplementary guidance

The Department of Communities and LocalGovernment occasionally issues additionalmaterial to aid interpretation of the guidancein Approved Documents. This material may beconveyed in official letters to chief executives oflocal authorities and Approved Inspectors and/or posted on the websites accessed through:www.communities.gov.uk/planningandbuilding/buildingregulations/.

Interaction with other legislation

The Workplace (Health, Safety and Welfare)Regulations 1992

The Workplace (Health, Safety and Welfare)Regulations 1992 contain some requirementswhich affect building design. The mainrequirements are now covered by the BuildingRegulations, but for further information see:Workplace health, safety and welfare. Workplace(Health, Safety and Welfare) Regulations 1992.Approved Code of Practice L24. Published byHSE Books 1992 (ISBN 0 7176 0413 6).

The Workplace (Health, Safety and Welfare)Regulations 1992 apply to the common parts offlats and similar buildings if people such ascleaners and caretakers are employed to work inthese common parts. Where the requirements ofthe Building Regulations that are covered by thisPart do not apply to dwellings, the provisionsmay still be required in the situations describedabove in order to satisfy the WorkplaceRegulations.

The Clean Air Act 1993

Under the Clean Air Act 1993 local authoritiesmay declare the whole or part of the district ofthe authority to be a smoke control area. It is anoffence to emit smoke from a chimney of abuilding, from a furnace or from any fixed boilerif located in a designated smoke control areaunless an authorised fuel was used. It is also anoffence to acquire an unauthorised fuel for usewithin a smoke control area unless it is used in an

exempt appliance (exempted from the controlswhich generally apply in the smoke control area).

Authorised fuels are fuels which are authorisedby Statutory Instruments (Regulations) madeunder the Clean Air Act 1993. These includeinherently smokeless fuels such as gas,electricity and anthracite together with specifiedbrands of manufactured solid smokeless fuels.These fuels have passed tests to confirm thatthey are capable of burning in an open fireplacewithout producing smoke.

Exempt appliances are appliances (ovens, wood

burners, boilers and stoves) which have beenexempted by Statutory Instruments (Orders)under the Clean Air Act 1993. These have passedtests to confirm that they are capable of burningan unauthorised or inherently smoky solid fuelwithout emitting smoke.

More information and details of authorised fuelsand exempt appliances can be found on theinternet at http://smokecontrol.defra.gov.uk/


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J THE REQUIREMENTS

Maintenance

The guidance in this Approved Documentprovides a way of ensuring that combustionappliances can function safely. For combustionappliances to continue to work safely andeffectively it is essential that they are adequatelyand regularly serviced and maintained.


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This Approved Document, which takes effecton 1October2010, deals with the followingRequirements which are contained in the BuildingRegulations 2010 (as amended by SI 2001/2214).

Requirement Limits on application

Part J Combustion Appliances and Fuel Storage Systems

Air supply

J1. Combustion appliances shall be so installed that there is an

adequate supply of air to them for combustion, to prevent

overheating and for the efficient working of any flue.

Discharge of products of combustion

J2. Combustion appliances shall have adequate provision for

the discharge of products of combustion to the outside air.

Warning of release of carbon monoxide

J3. Where a fixed combustion appliance is provided, appropriate

provision shall be made to detect and give warning of the

release of carbon monoxide.

Protection of building

J4. Combustion appliances and fluepipes shall be so installed,

and fireplaces and chimneys shall be so constructed and installed,

as to reduce to a reasonable level the risk of people suffering

burns or the building catching fire in consequence of their use.

Provision of information

J5. Where a hearth, fireplace, flue or chimney is provided

or extended, a durable notice containing information on the

performance capabilities of the hearth, fireplace, flue or chimneyshall be affixed in a suitable place in the building for the

purpose of enabling combustion appliances to be safely installed.

Protection of liquid fuel storage systems

J6. Liquid fuel storage systems and the pipes connecting them

to combustion appliances shall be so constructed and separated

from buildings and the boundary of the premises as to reduce

to a reasonable level the risk of the fuel igniting in the event of

fire in adjacent buildings or premises.

Protection against pollution

J7. Oil storage tanks and the pipes connecting them to

combustion appliances shall:(a) be so constructed and protected as to reduce to a reasonable

level the risk of the oil escaping and causing pollution; and

(b) have affixed in a prominent position a durable notice

containing information on how to respond to an oil escape so as

to reduce to a reasonable level the risk of pollution.

Requirements J1 and J2 apply only to fixed combustion

appliances (including incinerators).

Requirement J3 applies only to fixed combustion appliances

located in dwellings.

Requirement J6 applies only to:

(a) fixed oil storage tanks with capacities greater than 90 litres

and connecting pipes; and

(b) fixed liquefied petroleum gas storage installations with

capacities greater than 150 litres and connecting pipes, which

are located outside the building and which serve fixed

combustion appliances (including incinerators) in the building.

Requirement J7 applies only to fixed oil storage tanks with

capacities of 3500 litres or less, and connecting pipes, which:

(a) are located outside the building; and

(b) serve fixed combustion appliances (including incinerators)

in a building used wholly or mainly as a private dwelling, but

does not apply to buried systems.

Particular reference should be made to:

Approved Document Bfor guidance oncompartmentation of buildings for fire safetypurposes and for appropriate degrees of fireresistance for compartment boundaries.

Approved Document Ffor guidance on ventilationfor health, and provision of extract ventilationusing open flued combustion appliances.

The Requirements J1/J2/J3/J4/J5/J6COMBUSTION APPLIANCES AND FUEL STORAGE SYSTEMS J


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Introduction to the provisions

0.1 This Approved Document gives guidanceon how to satisfy the requirements of Part J.Although Part J applies to the accommodationof any combustion installation and liquid fuel

storage system within the Limits on Application,the guidance in this Approved Document hasbeen prepared mainly with domestic installationsin mind, such as those comprising space andwater heating systems and cookers and theirflues, and their attendant oil and liquefiedpetroleum gas (LPG) fuel storage systems. Part Jdoes not include specific provisions relating tothe storage of solid fuel (including solid biofuel)but the relevant guidance in Approved DocumentB should be followed.

0.2 The guidance applies to combustioninstallations having power ratings and fuel

storage capacities up to the limits shown in a) toc) below. Guidance which applies generally isgiven in this section and Section 1. More specificguidance is then given in:

a. Section 2 for solid fuel installations of up to45kWrated output;

b. Section 3 for gas installations of up to 70kWnet (77.7kW gross)rated input;

c. Section 4 for oil installations of up to 45kWrated heat output.

Section 5 gives guidance on requirement J5 for

heating oil storage installations with capacitiesup to 3500 litres and LPG storage installationswith capacities up to 1.1 tonne, although there isno size limit on the application of requirement J5.Section 5 also gives guidance on requirement J6,which is limited to installations where the capacityof the oil storage tank is 3500 litres or less, servingbuildings used wholly or mainly as private dwellings.

0.3 For installations subject to the requirementsof part J but outside the scope of this ApprovedDocument, such as incinerators or installationswith higher ratings than those mentioned above,specialist guidance may be necessary. However,

some larger installations may be shown to complyby adopting the relevant recommendations tobe found in the CIBSE Guide Band practicestandards produced by BSI and IGEM.

Explanation of terms used

0.4 The following definitions have beenadopted solely for the purposes of providingclarity in this Approved Document.

1. An appliance compartmentis an enclosurespecifically constructed or adapted toaccommodate one or more combustionappliances.

2. A balanced compartmentis a method ofinstalling an open-flued appliance into acompartment which is sealed from theremainder of the building and whose ventilationis so arranged in conjunction with the applianceflue as to achieve a balanced flue effect.

3. A balanced flueappliance is a type of room-sealed appliance which draws its combustionair from a point outside the building adjacentto the point at which the combustion productsare discharged, the inlet and outlet being sodisposed that wind effects are substantiallybalanced. Balanced flues may run vertically,but in the most common configuration theydischarge horizontally through the externalwall against which the appliance is situated.

4. The boundaryis the boundary of the land orbuildings belonging to and under the control

of the building owner. Depending upon theparagraphs of this Approved Document towhich it applies, it may be drawn only aroundthe perimeter of the land in question orextended to the centreline of adjacent routesor waterways as shown in Diagram 1.

5. A Building Control Bodyis a body thatcarries out checks for compliance with theBuilding Regulations on plans of building workand on the building work itself. The BuildingControl Body may be either the local authorityor an Approved Inspector. For further details,see the manual to the Building Regulations.

6. The capacityof an oil tank is its nominalcapacity as stated by the manufacturer. It isusually 95 per cent of the volume of liquidrequired to fill it to the brim.

Section 0: General guidance

Diagram 1 Boundaries in thisApproved Document


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7. A chimneyis a structure consisting of a wallor walls enclosing one or more flues (seeDiagram 2). In the gas industry, the chimneyfor a gas appliance is commonly calledthe flue.

8. A combustion appliance(or appliance) is anapparatus where fuel is burned to generateheat for space heating, water heating, cookingor other similar purpose. The appliance doesnot include systems to deliver fuel to it or forthe distribution of heat. Typical combustionappliances are boilers, warm air heaters,water heaters, fires, stoves and cookers.

9. The designationsystem in BS EN 1443:2003expresses the performance characteristics ofa chimney or its components, as assessed inaccordance with an appropriate Europeanproduct standard, by means of a code suchas EN 1234 T400N1 D1 Gxx. Furtherinformation is given in Appendix G.

Sleeve

Diagram 2 Chimneys and flues

GENERAL GUIDANCE J


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10. A draught breakis an opening formed by afactory-made component into any part of theflue serving an open-flued appliance. Suchopenings may be provided to allow dilutionair to be drawn into a flue or to lessen theeffects of down-draught on combustion inthe appliance.

11. A draught diverteris a form of draught breakintended to prevent conditions in the main lengthof flue from interfering with the combustionperformance of an open-flued appliance (seeDiagram 3(a)). It allows the appliance tooperate without interference from down-draughts that may occur in adverse windconditions and excessive draught.

12. A draught stabiliseris a factory-madecounter-balanced flap device admitting airto the flue, from the same space as thecombustion air, to prevent excessive variationsin the draught (see Diagram 3(b)). It is usual

for these to be in the fluepipe or chimney, butthey may be located on the appliance.

13. Equivalent areais defined in BS EN 13141-1:2004 as the area of a sharp-edged circularorifice which would pass the same air flowrate at the same applied pressure differenceas the product or device being tested. Theequivalent area of a simple ventilator will beless than the geometrical free area and forcomplex products may be significantly less.

14. Factory-made metal chimneys(also knownas system chimneys) are prefabricated

chimneys that are commonly manufacturedas sets of components for assembly on site(although they can be supplied as one unit),having the performance appropriate for the

intended appliance. They are available invarious materials and types ranging fromsingle-walled metal chimneys suitable forsome gas appliances to twin-walled chimneyswith insulation sandwiched between an innerliner and an outer metal wall which aredesigned for oil or solid fuel use.

15. In a fanned draughtinstallation, the properdischarge of the flue gases depends upon theoperation of a fan, which may be separatelyinstalled in the flue or may be an integralpart of the combustion appliance. Fans incombustion appliances either may extractflue gases from the combustion chamber ormay cause the flue gases to be displacedfrom the combustion chamber if the fanis supplying it with air for combustion.Appliances with fans providing the combustionair (including most oil-fired and many gas-fired boilers) are also commonly referred toas forced draught appliances (see Diagram

4). Flues in fanned draught installations runhorizontally or vertically and can be at higheror lower pressures than their surroundings,dependent upon the location of the fan.

16. A fire compartmentis a building or part ofa building comprising one or more rooms,spaces or storeys constructed to preventthe spread of fire to or from another part ofthe same building or an adjoining building.(A roof-space above the top storey of afire compartment is included in that firecompartment.) A separated partof a buildingis a form of compartmentation in which part

of a building is separated from another part ofthe same building by a compartment wall.Such walls run the full height of the part andare in one vertical plane. Further informationon this is given in Approved Document B Vol2 (see Section 8 Compartmentation andAppendix C Methods of Measurement).

17. A fireplace recessis a structural opening(sometimes called a builders opening) formedin a wall or in a chimney breast, from which achimney leads and which has a hearth at itsbase. Simple structural openings (Diagram5(a)) are suitable for closed appliances such

as stoves, cookers or boilers, but gathers(Diagram 5(b)) are necessary for accommodatingopen fires. Fireplace recesses are often linedwith firebacks to accommodate inset openfires (Diagram 5(c)). Lining components anddecorative treatments fitted around openingsreduce the opening area. It is the finishedfireplace opening area which determines thesize of flue required for an open fire in sucha recess.

18. The fire resistanceof a component orconstruction is a measure of its ability towithstand the effects of fire in one or more

ways for a stated period of time. Guidance ondetermination of performance in terms of fireresistance is given in Approved Document B(Fire Safety).

J GENERAL GUIDANCE

Diagram 3 Draught diverter anddraught stabiliser


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19. A fire wallis a means of shielding a fuel tankfrom the thermal radiation from a fire. ForLPG tanks, it also ensures that gas accidentallyleaking from the tank or fittings must travel bya longer path and therefore disperse safely,before reaching a hazard such as an openingin a building, a boundary or other potentialignition source.

20. A flue is a passage that conveys the productsof combustion from an appliance to theoutside air (see Diagram 2).

21. Flueblock chimneysystems consist of a setof factory-made components, made fromprecast concrete, clay or other masonry units,that are designed for assembly on site toprovide a complete chimney having theperformance appropriate for the intendedappliance. There are two types of commonsystems, one being solely for use with gas-

burning appliances and the other, often calledchimney block systems, being primarilydesigned for solid fuel-burning appliances.

GENERAL GUIDANCE J

Diagram 4 Types of installation


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22. A flue box is a factory made unit, usually madeof metal, which is similar to a prefabricatedappliance chamber except that it is designedto accommodate a gas burning appliance inconjunction with a factory-made chimney.

23. A flueless applianceis one which is designedto be used without connection to a flue. Itsproducts of combustion mix with thesurrounding room air and are eventuallytransported to the outside as stale air leavesthe room (see Diagram 4(g)).

24. A flue lineris the wall of the chimney that is in

contact with the products of combustion (seeDiagram 2), such as a concrete flue liner, theinner liner of a factory-made chimney system ora flexible liner fitted into an existing chimney.

25. A flue outletis the point at which the productsof combustion are discharged from the flue tothe outside atmosphere, such as the top of achimney pot or flue terminal.

26. A fluepipeis a pipe, either single walled (bareor insulated) or double walled, which connectsa combustion appliance to a flue in a chimney.For clarity, when used in this way, it may be

called a connecting fluepipe. (Fluepipe is alsoused to describe the tubular componentsfrom which some factory made chimneys forgas and oil appliances are made or fromwhich plastic flue systems are made).

27. A hearthis a base intended to safely isolate acombustion appliance from people, combustibleparts of the building fabric and soft furnishings.The exposed surface of the hearth provides aregion around the appliance which can be keptclear of anything at risk of fire. The body ofthe hearth may be thin insulating board, asubstantial thickness of material such asconcrete or some intermediate provisiondependent upon the weight and downwardheat emission characteristics of the appliance(s)upon it (see Diagram 6).

28. The heat input rateis the maximum rate ofenergy flow into an appliance. It is calculatedas the rate of fuel flow to the appliancemultiplied by either the fuels gross or netcalorific value.

Note:Traditionally, the UK has used Grossvalues, most European standards use Net values.Thus for gas appliances it is now the norm toexpress this rating as a net value (kW (net)).

29. Installation instructionsare those instructionsproduced by manufacturers to enable installersto correctly install and test appliances andflues and to commission them into service.

30. In a natural draughtflue, the combustionproducts flow into the flue as a result of thedraught produced due to the differencebetween the temperature of the gases within

J GENERAL GUIDANCE

Diagram 5 Fireplace recesses


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the flue and the temperature of the ambientair. Taller flues produce a greater draught attheir base. Except for those balanced flueappliances which are designed to dischargedirectly through the wall adjacent to theappliance, a satisfactory natural draughtrequires an essentially vertical run of flue(see Diagram 4 (a) and (b)).

31. Non-combustible material. This is thehighest level of reaction to fire performance.

Non-combustible materials include:

a. any material which when tested toBS 476-11:1982 (2007) does not flamenor cause any rise in temperature oneither the centre (specimen) or furnacethermocouples; and

b. products classified as non-combustiblein tests following the procedures inBS 476-4:1970 (2007);

c. any material classified as class A1 inaccordance with BS EN 13501-1:2002 Fireclassification of construction products

and building elements. Classificationusing data from reaction to fire tests.

Typical examples of such materials to befound in buildings include totally inorganicmaterials such as concrete, fired clay,ceramics, metals, plaster and masonrycontaining not more than 1 per cent byweight or volume of organic material. (Usein buildings of combustible metals such asmagnesiumaluminium alloys should beassessed in each individual case.)

More detailed information is given in

Approved Document B (Fire Safety).32. ANotified Body, for the purposes of the Gas

Appliances (Safety) Regulations (1995), means:

a. a body which is approved by the Secretary ofState for Trade and Industry as beingcompetent to carry out the required Attestationprocedures for gas appliances and whosename and identification number has beennotified by him/her to the Commission of theEuropean Community and to other memberStates in accordance with the Gas Appliances(Safety) Regulations (1995);

b. a body which has been similarly approved for

the purposes of the Gas Appliances Directiveby another member State and whose nameand identification number has been notified tothe Commission and to other member Statespursuant to the Gas Appliances Directive.

33. An open-flued applianceis one which drawsits combustion air from the room or spacewithin which it is installed and which requiresa flue to discharge its products of combustionto the outside air (see Diagram 4 (a), (c) and (e)).

34. A prefabricated appliance chamberis a setof factory-made precast concrete components

designed to provide a fireplace recess toaccommodate an appliance such as a stove,and incorporates a gather when used with anopen fire. The chamber is normally positionedagainst a wall and may be designed tosupport a chimney. The chamber andchimney are often enclosed to create a falsechimney breast (see also flue box).

35. The rated heat input(sometimes shortenedto rated input) for a gas appliance is themaximum heat input rate at which it can beoperated, as declared on the appliance dataplate. (See also heat input rate.)

36. The rated heat outputfor an oil appliance isthe maximum declared energy output rate(kW) as declared on the appliance data plate.

Diagram 6 The functions of hearths

GENERAL GUIDANCE J


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37. The rated heat outputfor a solid fuel applianceis the manufacturers declared nominal energyoutput rate (kW) for the appliance. This may bedifferent for different fuels.

38. A room-sealed appliancemeans anappliance whose combustion system issealed from the room in which the applianceis located and which obtains air forcombustion from a ventilated uninhabitedspace within the building or directly from theopen air outside the building and which ventsthe products of combustion directly to openair outside the building (see Diagram 4 (b), (d)and (f)).

39. Solid biofuel means, for the purpose of thisApproved Document, a solid fuel derivedfrom plants and trees. It can include logs,wood chips, wood pellets and otherprocessed plant material.

40. A throatis a contracted part of the flue

between a fireplace recess and its chimney(see Diagram 22). Throats are usually formedfrom prefabricated components as shown inDiagram 29.

Measuring the size of flues

and ducts

0.5 The size a flueor duct (area, diameter etc)should be measured at right angles to thedirection in which gases flow. Where offsetcomponents are used, they should not reducethe fluearea to less than the minimum requiredfor the combustion appliance(see Diagram 7).

Diagram 7 Measurement of flues and ducts

J GENERAL GUIDANCE


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Performance

1.1 In the Secretary of States viewrequirements J1 to J5 will be met if the buildingprovisions for the safe accommodation ofcombustion appliances:

a. enable the admission of sufficient air for:

i. the proper combustion of fuel and theoperation of flues; and

ii. the cooling of appliances wherenecessary;

b. enable normal operation of applianceswithout the products of combustionbecoming a hazard to health.

c. incorporate an appropriate means of warningof a release of Carbon Monoxide for fixedappliances that burn solid fuels;

d. enable normal operation of applianceswithout their causing danger through damageby heat or fire to the fabric of the building;

e. have been inspected and tested to establishsuitability for the purpose intended;

f. have been labelled to indicate performancecapabilities.

Note:Whilst, for the purposes of requirementJ2A, it is considered appropriate to require

carbon monoxide alarms only with solid fuelappliances, such alarms can still reduce the riskof poisoning from other types of appliance.

Air supply for combustion

appliances

1.2 Combustion appliancesrequire ventilationto supply them with air for combustion. Ventilationis also required to ensure the proper operationof fluesor, in the case of flueless appliances, toensure that the products of combustion aresafely dispersed to the outside air. Installation ofroom-sealed appliancesor those with a directlyconnected ducted external air supply will minimiseventilation energy losses from the room and therisk of cold draughts. In some cases, combustionappliancesmay also require air for cooling controlsystems and/or to ensure that casings remainsafe to touch (see Diagram 8). General guidanceon where it may be necessary to install air ventsfor these purposes is given below.

1.3 Air vent sizes, which are dependent uponthe type of fuel burned, are given in Sections 2, 3and 4 and are for one combustion applianceonly.The air supply provisions will usually need to beincreased where a room contains more than oneappliance (such as a kitchen containing anopen-flued boiler and an open-flued cooker).

Permanently open ventilation

of rooms

1.4 A room containing an open-flued appliancemay need permanently open air vents. An open-flued appliance must receive a certain amount ofair from outside (combustion air in Diagram 8)dependent upon its type and rating. Infiltrationthrough the building fabric may be sufficientbut for certain appliance ratings and forms ofconstruction, permanent openings are necessary(see Diagram 8).

Permanent ventilation of appliance

compartments

1.5 Appliance compartmentsthat encloseopen-flued combustion appliancesshould beprovided with vents large enough to admit all ofthe air required by the appliance for combustionand proper flue operation, whether the compartmentdraws its air from a room or directly from outside(see Diagram 8 (b) and (c)).

1.6 Where appliances require cooling air,appliance compartmentsshould be large enoughto enable air to circulate and high- and low-levelvents should be provided (see Diagram 8 (d), (e),(f) and (g)).

1.7 Where appliances are to be installed within

balanced compartments(see paragraph 0.4(2)),special provisions will be necessary and theappliance and ventilation system manufacturersinstructions should be followed.

Ventilation of other rooms

or spaces

1.8 If an appliance isroom-sealedbut takes itscombustion air from another space in the building(such as the roof void) or if a fluehas a permanentopening to another space in the building (such aswhere it feeds a secondary fluein the roof void),

that space should have ventilation openingsdirectly to outside. Where the roof-space is tobe used as a source of air for a combustioninstallation serving a dwelling, the dwelling roofventilation provisions suggested in ApprovedDocument C would normally be satisfactory.

1.9 Where flued appliances are supplied withcombustion air through air vents which open intoadjoining rooms or spaces, the adjoining roomsor spaces should have air vent openings of atleast the same size direct to the outside. Airvents for flueless appliances, however, shouldopen directly to the outside air.

Section 1: Provisions which apply generallyto combustion installations


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PROVISIONS WHICH APPLY GENERALLY TOJ COMBUSTION INSTALLATIONS

Diagram 8 General air supply to a combustion appliance(for sizes see Sections 2, 3 and 4)


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Permanently open air vents

1.10 Permanently open air vents should benon-adjustable, sized to admit sufficient air forthe purpose intended and positioned where theyare unlikely to become blocked. Ventilators shouldbe installed so that building occupants are notprovoked into sealing them against draughts ornoise. Ventilation openings should not be madein fire-resistingwalls other than external walls(although they should not penetrate those partsof external walls shielding LPG tanks). Air ventsshould not be located within a fireplace recessexcept on the basis of specialist advice.

1.11 A way of meeting the requirement would beto size permanently open air vents so that theirequivalent areais sufficient for the appliance(s) tobe installed (taking account where necessary ofobstructions such as grilles and anti-verminmesh), and to site them:

a. outside fireplace recessesand beyond thehearthsof open fires so that dust or ash will

not be disturbed by draughts; andb. in a location unlikely to cause discomfort from

cold draughts.

1.12 Where ventilation is to be provided via asingle proprietary assembly, for example whenit is proposed to use a proprietary ventilator withintegral grilles to bridge a cavity wall, the equivalentareaof the ventilator should be taken as thatdeclared by the manufacturer having beenmeasured by the method in BS EN 13141-1:2004.

1.13 Where two or more components are to beused to provide a non-proprietary assembly, the

assembly should be kept as simple and smooth aspossible. The assembly should be taken to havean equivalent areaequal to that of the componentwith the smallest equivalent areain the assembly.

1.14 The equivalent areastated in the ventilatormanufacturers literature or marked on the air ventshould be used whenever it is available, as this candiffer considerably from the free area measured atone end of the air vent. When this is not availablethe equivalent areaof a simple ventilator with nointernal baffles can be taken as the totalunobstructed cross-sectional area, measured inthe plane where this area is at a minimum and at

right angles to the direction of air flow. For anairbrick, grille or louvre with apertures no smallerthan 5mm, it will be the aggregate free area ofthe individual apertures as shown Diagram 9.

PROVISIONS WHICH APPLY GENERALLY TOCOMBUSTION INSTALLATIONS J

Equivalent

or Free area 1

(a) Ventilator assembled on site from

components

The ventilator area is the smaller of

equivalent area (1 or 2) (as declared

by manufacturer), free area (1 or 2)

(as measured in (b)) or the duct area.

Equivalent

or Free area 2

Diagram 9 Ventilator free areas


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1.15 Grilles or meshes protecting air vents fromthe entry of animals or birds should have aperturedimensions no smaller than 5mm.

1.16 Discomfort from cold draughts can beavoided by supplying air directly to appliances,locating vents close to appliances (for exampleby using floor vents), by drawing air fromintermediate spaces such as hallways or byensuring good mixing of incoming cold air byplacing external air vents close to ceilings (seeDiagrams 10 and 11). In noisy areas it may benecessary to install noise-attenuated ventilatorsto limit the entry of noise into the building.Transfer or connecting ventilation should be atlow level to reduce the transfer of smoke in theevent of a fire and otherwise meet the guidancegiven in Approved Document B.

1.17 Buildings may have air-tight membranes intheir floors to isolate them from the ground below.Ventilation ducts or vents installed to supply airto combustion appliancesshould not penetratethese membranes in a way that will render themineffective. Such membranes (including radon-proof membranes) are described in BRE ReportBR 414 (2001) and BRE Report BR 211 (2007),which give guidance when service penetrationsare necessary.

Provisions complying with both

Part F and Part J

1.18 Rooms or spaces intended to containopen-flued combustion appliancesmay needpermanent ventilation to comply with Part J andadjustable ventilation to comply with Part F.Permanently open air vents for combustion

appliancescan be accepted in place of some orall of the adjustable background ventilation forhealth, dependent upon opening area andlocation. However adjustable vents installed tomeet the requirements of Part F cannot be usedas substitutes for the ventilation openingsneeded to comply with Part J unless they arefixed permanently open.

1.19 Rooms or spaces intended to containflueless appliancesmay need: permanentventilation and purge ventilation (such as openablewindows) to comply with Part J; and adjustableventilation and rapid ventilation to comply with

Part F. Permanent ventilation provisions tocomply with Part J may be acceptable in place ofadjustable ventilation provisions for Part Fsubject to the limitations described in Paragraph1.18. Openable elements installed for the rapidventilation of rooms and other provisions madefor the rapid ventilation of kitchens, in order tocomply with Part F, may be acceptable in placeof openable elements for the rapid ventilation ofrooms or spaces containing flueless appliances.


Well-

Well-

Diagram 10 Location of permanent air vent openings, some examples


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Interaction of mechanical extract

ventilation and open-flued

combustion appliances

1.20 Extract fans lower the pressure in a building,which can cause the spillage of combustionproducts from open-flued appliances. This canoccur even if the appliance and the fan are indifferent rooms. Ceiling fans produce air currents

and hence local depressurisation, which can alsocause the spillage of flue gases from open-fluedappliancesor from solid fuel open fires. In buildingswhere it is intended to install open-flued combustionappliancesand extract fans, the combustionappliancesshould be able to operate safely whetheror not the fans are running. A way of showingcompliance in these circumstances would be tofollow the installation guidance below, and toshow by tests that combustion appliancesoperate safely whether or not fans are running.

a. For gas appliances: where a kitchen containsan open-flued appliance, the extract rate of

the kitchen extract fan should not exceed20 litres/second (72m/hour).

b. For oil appliances: where a room contains anopen-flued appliancethe extract rate shouldbe limited to 40 litres/second for an appliancewith a pressure jet burner and 20 litres/secondfor an appliance with a vaporising burner.

c. For solid fuel appliances: avoid installingextract ventilation in the same room. Anopen-flued appliancein a kitchen may satisfythe requirements of Part F through passivestack ventilation. Refer to Approved

Document F. If mechanical extraction isunavoidable then seek specialist advice toensure safe operation of the appliance.

d. For commercial and industrial installations,specialist advice may be necessary regardingthe possible need for the interlocking of gasheaters and any mechanical ventilationsystems.

e. When fans are used to extract radon frombelow a building follow the guidance in BREGood Building Guide GBG 25.

1.21 A suitable test would be to check forspillage when appliances are subjected to thegreatest possible depressurisation. A prerequisitefor this condition is that all external doors,windows and other adjustable ventilators tooutside are closed. The depressurisation at theappliance will depend on the particular combinationof fans in operation (fans in the room containingthe appliance and fans elsewhere in the building)and the pattern of open internal doors, hatchesetc. which is established at the time of the test(when fans should be on their maximum useablesetting), and the specific combination causingthe greatest depressurisation at the appliance

depends upon the circumstances in each case.Several tests (which should include a test withthe door leading into the room of installationclosed and all fans in that room switched on) maytherefore be necessary to demonstrate the safeoperation of the appliance with reasonablecertainty. The effect of ceiling fans should bechecked during the tests.

1.22 The presence of some fans may be obvious,such as those on view in kitchens, but othersmay be less obvious: fans installed in domesticappliances such as tumble dryers and fans fittedto other open-fluedcombustion appliancescan

also contribute to depressurisation. In addition,fans may also be provided to draw radon gasfrom the ground below a building (see Paragraph1.17).


Diagram 11 Provision of permanent air vent openings in a solid floor


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1.23 The appliance manufacturersinstallationinstructionsmay describe a suitable spillagetest for gas appliances but the procedure inBS 5440-1:2008 can be used. For oil-firedappliances the effects of fans can be checkedand, where spillage or flue draught interference isidentified, it may be necessary to add additionalventilation to the room or space. A flue draught

interference test for oil-fired appliances isdescribed in OFTEC Technical Books 2, 4 and 5.

Provision of flues

1.24 Appliances other than flueless appliancesshould incorporate or be connected to suitableflueswhich discharge to the outside air.

1.25 This Approved Document providesguidance on how to meet the requirements interms of constructing a flueor chimney, whereeach flueserves one appliance only. Fluesdesigned to serve more than one appliance canmeet the requirements by following the guidancein BS 5410-1:1997 for oil- and BS 5440-1:2008for gas-fired systems. However, each solid fuelappliance should have its own flue.

Condensates in flues

1.26 Chimneysand fluesshould providesatisfactory control of water condensation.Ways of providing satisfactory control include:

a. for chimneysthat do not serve condensingappliances, by insulating fluesso that fluegases do not condense in normal operation

b. for chimneysthat do serve condensingappliances:

i. by using lining components that areimpervious to condensates and suitablyresistant to corrosion (BS EN 1443:2003W designation) and by makingappropriate provisions for draining,avoiding ledges, crevices, etc

ii. making provisions for the disposal ofcondensate from condensing appliances.

Construction of masonry

chimneys1.27 New masonry chimneysshould beconstructed with flue linersand masonry suitablefor the intended application. Ways of meeting therequirement would be to use bricks, medium-weight concrete blocks or stone (with wallthicknesses as given in Section 2, 3 or 4according to the intended fuel) with suitablemortar joints for the masonry and suitablysupported and caulked liners. Liners suitable forsolid fuel appliances (and generally suitable forother fuels) could be:

a. liners whose performance is at least equal to

that corresponding to the designationT400N2 D 3 G, as described in BS EN 1443:2003,such as:

i. clay flue linerswith rebates or sockets forjointing meeting the requirements forClass A1 N2 or Class A1 N1 as describedin BS EN 1457:2009; or

ii. concrete flue linersmeeting therequirements for the classification TypeA1, Type A2, Type B1 or Type B2 asdescribed in BS EN 1857:2003; or

iii. other products that meet the criteria in a).

1.28 Liners should be installed in accordancewith their manufacturers instructions. Appropriatecomponents should be selected to form the fluewithout cutting and to keep joints to a minimum.Bends and offsets should be formed only withmatching factory-made components. Liners needto be placed with the sockets or rebate endsuppermost to contain moisture and othercondensates in the flue. Joints should be sealedwith fire cement, refractory mortar or installed inaccordance with their manufacturers instructions.

Spaces between the lining and the surroundingmasonry should not be filled with ordinary mortar.In the absence of liner manufacturers instructions,the space could be filled with a weak insulatingconcrete such as mixtures of:

a. one part ordinary Portland cement to 20 partssuitable lightweight expanded clay aggregate,minimally wetted; or

b. one part ordinary Portland cement to 6 partsVermiculite; or

c. one part ordinary Portland cement to 10 partsPerlite.

Construction of flueblock

chimneys

1.29 Flueblock chimneysshould be constructedof factory-made components suitable for theintended application installed in accordance withthe manufacturers instructions. Ways of meetingthe requirement for solid fuel appliances (andgenerally suitable for other fuels) include using:

a. flueblocks whose performance is at leastequal to that corresponding to thedesignationT400 N2 D 3 G, as described

in BS EN 1443:2003, such as:i. clay flueblocks at least meeting the

requirements for Class FB1 N2 asdescribed in BS EN 1806:2006

ii. other products that meet the criteria in a).

b. blocks suitable for the purpose lined inaccordance with Paragraph 1.27.

1.30 Joints should be sealed in accordancewith the flueblock manufacturers instructions.Bends and offsets should be formed only withmatching factory-made components.



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Material change of use

1.31 Where a building is to be altered fordifferent use (e.g. it is being converted into flats)the fire resistanceof walls of existing masonrychimneysmay need to be improved as shown inDiagram 12.

Connecting fluepipes1.32 Satisfactory components for constructingconnecting fluepipesinclude:

a. cast iron fluepipescomplying with BS41:1973 (1998)

b. metal flue pipes appropriately designated inaccordance with BS EN1856-2:2004 to suitthe appliance and types of fuels to be burnt refer to detailed guidance in Sections 2, 3and 4.

c. vitreous enamelled steel pipe complying withBS 6999:1989 (1996)

d. other fluepipeshaving the necessaryperformance designationfor use with theintended appliance.

1.33 Fluepipeswith spigot and socket jointsshould be fitted with the socket facing upwardsto contain moisture and other condensates inthe flue. Joints should be made gas-tight. A

satisfactory way of achieving this would be touse proprietary jointing accessories or, whereappropriate, by packing joints with non-combustible rope and fire cement.

Repair of flues

1.34 It is important to the health and safetyof building occupants that renovations,refurbishments or repairs to flue linersshouldresult in fluesthat comply with the requirementsof J2 to J5. The test procedures referred to inparagraph 1.55 and in Appendix E can be usedto check this.

1.35 Fluesare controlled services as defined inRegulation 2 of the Building Regulations, that isto say they are services in relation to which Part Jof Schedule 1 imposes requirements. If renovation,refurbishment or repair amounts to or involvesthe provision of a new or replacement flue liner, itis building work within the meaning of Regulation3 of the Building Regulations. Building work andmust not be undertaken without prior notificationto the local authority. Examples of work thatwould need to be notified include:

a. relining work comprising the creation of newflue walls by the insertion of new linings suchas rigid or flexible prefabricated components

Diagram 12 Material change of use: fire protection of chimneys passingthrough other dwellings



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b. a cast in situ liner that significantly alters thefluesinternal dimensions.

Anyone in doubt about whether or not anyrenovation, refurbishment or repair work involvinga flueis notifiable building work, could consultthe building control department of their localauthority, or an approved inspector.

Re-use of existing flues1.36 Where it is proposed to bring a fluein anexisting chimneyback into use or to re-use a fluewith a different type or rating of appliance, theflueand the chimneyshould be checked and, ifnecessary, altered to ensure that they satisfy therequirements for the proposed use. A way ofchecking before and/or after remedial workwould be to test the flueusing the proceduresin Appendix E.

1.37 A way of refurbishing defective flueswould be to line them using the materials and

components described in Sections 2, 3, and 4dependent upon the type of combustionapplianceproposed. Before relining flues, theyshould be swept to remove deposits.

1.38 A fluemay also need to be lined to reducethe flue area to suit the intended appliance.Oversize fluescan be unsafe.

1.39 If a chimneyhas been relined in the pastusing a metal lining system and the appliance isbeing replaced, the metal liner should also bereplaced unless the metal liner can be proven tobe recently installed and can be seen to be ingood condition.

Use of flexible metal flue liners for

the relining of chimneys

1.40 A way of relining a chimneywould be to usea flexible metal flue liner, appropriately designatedin accordance with BS EN1856-2:2004 to suit theappliance, fuel and flue gas characteristics.Flexible flue linersshould be used only to reline achimneyand should not be used as the primaryliner of a new chimney. They can be used toconnect gas back boilers to chimneyswhere theappliance is located in a fireplace recess.

Use of plastic fluepipe systems

1.41 A way of using plastic flue systems andliners would be to use a plastic flue, appropriatelydesignated in accordance with BS EN 14471:2005to suite the appliance, fuel and fluecharacteristics.Plastic fluepipe systems can be acceptable insome cases, for example with condensing boilerinstallations, where the fluepipesare supplied byor specified by the appliance manufacturer asbeing suitable for purpose.

Factory-made metal chimneys

1.42 Ways of meeting the requirements whenproposing factory-made metal chimneysinclude:

a. using component systems appropriatelydesignated in accordance with BS EN1856-1:2003 to suit the appliance and types of fuelsto be burnt and installing them in accordancewith the relevant recommendations ofBS EN 15287-1:2007;

b. for gas and for oil appliances where fluetemperatures will not normally exceed 250C,using twin-walled component systems (and,for gas, single-walled component systems)appropriately designated in accordance withBS EN1856-1:2003 to suit the appliance andtypes of fuels to be burnt and installing gasappliances in accordance with BS 5440-1:2008;

c. using any other chimneysystem that issuitable for the intended purpose andinstalled in accordance with the relevantrecommendations in BS EN 15287-1:2007 orBS 5440-1:2008, as appropriate to the typeof appliance being installed.

1.43 Where a factory-made metal chimneypasses through a wall, sleeves should be providedto prevent damage to the flueor building throughthermal expansion. To facilitate the checking ofgas-tightness, joints between chimneysectionsshould not be concealed within ceiling joistspaces or within the thicknesses of walls withoutproper access being provided (see paragraph 1.47).

1.44 When providing a factory-made metalchimney, provision should be made to withdrawthe appliance without the need to dismantle thechimney.

1.45 Factory-made metal chimneysshould bekept a suitable distance away from combustiblematerials. Ways of meeting the requirement forchimneysdesignated to BS EN 1856-1:2003comprise:

a. locating the chimneynot less than distancexx from combustible material, where xx isdefined in BS EN 1856-1:2003 as shown inDiagram 13;

b. where a chimneypasses through a cupboard,storage space or roof space, providing aguard placed no closer to the outer wall of

the chimneythan the distance in a) above.1.46 Where a factory-made metal chimneypenetrates a fire compartmentwall or floor, itmust not breach the fire separation requirementsof Part B. See Approved Document B for moreguidance but the requirements may be met by:

a. using a factory-made metal chimneyof theappropriate level of fire resistanceinstalled inaccordance with BS EN 1856-1:2003 AnnexNA; or

b. casing the chimneyinnon-combustiblematerialgiving at least half the fire resistance

recommended for the fire compartmentwallor floor.



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Concealed flues

1.47 Where a flueis routed within a void,appropriate means of access at strategiclocations should be provided to allow the

following aspects to be visually checked andconfirmed. This is necessary both when anappliance is first installed and subsequentlywhen the appliance is serviced:

the flueis continuous throughout its length

all joints appear correctly assembled and areappropriately sealed

the flueis adequately supported throughoutits length

any required gradient of fall back to the boiler(required to recover the condensate producedas part of the combustion process) and any

other required drain points have beenprovided.

Means of access for fluesneeds to be sufficientlysized and positioned to allow a visual inspectionto be undertaken of the flue, particularly at anyjoints in the flue. It is not intended that the meansof access should be sized to allow full physical

access to the flue system. Diagram 14 shows anacceptable approach for a fluein an ceiling void.

Fluesshould not pass through another dwellingsince access for inspection may not always beavailable to that dwelling and chimneysystemrunning through it. Fluesmay pass throughcommunal areas including purpose-designedducts where inspection access is provided.

Any means of access should not impair anyfire, thermal or acoustic requirements of theBuilding Regulations. Refer to the relevantguidance in Approved Documents B, L and E.Where necessary, inspection panels or hatchesshould be fitted with resilient seals and providethe similar standards of fire, thermal and acousticisolation to the surrounding structure.

Access hatches should be at least 300mm x300mm or larger where necessary to allowsufficient access to the void to look along thelength of the flue. Digram 14 shows anacceptable approach to providing access to ahorizontal fluelocated within a ceiling void.


Distance xx

distance (xxmm) asdesignated to BS EN 1856-1

xx

xx

Diagram 13 The separation of combustible material from a factory-made metalchimney designated to BS EN 1856-1:2003


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Configuration of natural draught

flues serving open-flued

appliances

1.48 Flue systems should offer least resistanceto the passage of flue gases by minimisingchanges in direction or horizontal length. A wayof meeting the requirement would be to buildfluesso that they are straight and vertical exceptfor the connections to combustion applianceswith rear outlets where the horizontal sectionshould not exceed 150mm. Where bends areessential, they should be angled at no more than45 to the vertical.

1.49 Provisions should be made to enable fluesto be swept and inspected. A way of makingreasonable provision would be to limit thenumber of changes of direction between thecombustion applianceoutlet and the flue outletto not more than four (each up to 45), with notmore than two of these being between an

intended point of access for sweeping and eitheranother point of access for sweeping or the flueoutlet. (90 factory-made bends, elbows or Teepieces in fluepipesmay be treated as being equalto two 45 bends (see Diagram 15)).


Flue terminal Flue terminal

External wall

Internalwall

Inspection hatch

x

x

x

Inspection hatch

Concealedflue connection

All voids containing concealed flues should have at least one inspection hatchmeasuring at least 300mm square.

No flue joint within the void should be more than 1.5m distant from the edge of

the nearest inspection hatch, i.e. dimension x in the diagram should be less than 1.5m.

Where possible inspection hatches should be located at changes of direction.Where this is not possible then bends should be viewable from both directions.

Accessibleflue connection

Boiler A

Boiler B

Any intervening jointsto be visible within1.5m of an inspectionhatch

Any intervening jointsto be visible within1.5m of an inspectionhatch

Inspection hatch

Inspection hatch

+

x

x

Diagram 14 Example locations of access panels for concealed horizontal flues


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Inspection and cleaning openings

in flues

1.50 A flueshould not have openings into morethan one room or space except for the purposes of:

a. inspection or cleaning; or

b. fitting an explosion door, draught break,draught stabiliseror draught diverter.

1.51 Openings for inspection and cleaningshould be formed using purpose factory-madecomponents compatible with the flue system,having an access cover that has the same levelof gas-tightness as the flue system and an equallevel of thermal insulation. Openings for cleaningthe flueshould allow easy passage of thesweeping brush. Covers should also be non-combustible except where fitted to a combustible

fluepipe(such as a plastic fluepipe). After theappliance has been installed, it should bepossible to sweep the whole flue.

Flues discharging at low level

near boundaries

1.52 Fluesdischarging at low level nearboundaries should do so at positions where thebuilding owner will always be able to ensure safeflue gas dispersal. A way of achieving this whereowners of adjacent land could build up to theboundarywould be to adopt the suggestions in

Diagram 34 or 41, as relevant.

Dry lining around fireplace

openings

1.53 Where a decorative treatment, such asa fireplace surround, masonry cladding or dry

lining, is provided around a fireplace opening,any gaps that could allow flue gases to escapefrom the fireplace opening into the void behindthe decorative treatment should be sealed toprevent such leakage. The sealing materialshould be capable of remaining in place despiteany relative movement between the decorativetreatment and the fireplace recess.

Condition of combustion

installations at completion

1.54 Responsibility for achieving compliance

with the requirements of Part J rests with theperson carrying out the work. That person maybe, e.g., a specialist firm directly engaged by aprivate client or it may be a developer or maincontractor who has carried out work subject toPart J or engaged a sub-contractor to carry it out.In order to document the steps taken to achievecompliance with the requirements, a reportshould be drawn up showing that materials andcomponents appropriate to the intendedapplication have been used and that flueshavepassed appropriate tests. A suggested checklistfor such a report is given at Appendix A andguidance on testing is given at Appendix E. Other

forms of report may be acceptable. Specialistfirms should provide the report to the client,developer or main contractor, who may be askedfor documentation by the Building Control Body.


Diagram 15 Bends in flues


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1.55 Fluesshould be checked at completionto show that they are free from obstructions,satisfactorily gas-tight and constructed withmaterials and components of sizes which suitthe intended application. Where the buildingwork includes the installation of a combustionappliance, tests should cover fluepipesand [thegas-tightness of] joints between fluepipesand

combustion applianceoutlets. A spillage test tocheck for compliance with J2 should be carriedout with the appliance under fire, as part ofthe process of commissioning to check forcompliance with Part L, and (in relevant cases)as required by the Gas Safety (Installation andUse) Regulations.

1.56 Hearthsshould be constructed withmaterials and components of sizes to suit theintended application and should show the areawhere combustible materials should not intrude.

Notice plates for hearths and flues

(Requirement J5)1.57 Where ahearth, fireplace (including a fluebox), flueor chimneyis provided or extended(including cases where a flueis provided as partof the refurbishment work), information essentialto the correct application and use of thesefacilities should be permanently posted in thebuilding. A way of meeting this requirementwould be to provide a notice plate as shown inDiagram 16 conveying the following information:

a. the location of thehearth, fireplace(or flue box) or the location of the beginningof the flue;

b. the category of the flueand generic types ofappliances that can be safely accommodated;

c. the type and size of the flue(or its liner if ithas been relined) and the manufacturers

name;d. the installation date.

1.58 Notice plates should be robust, indeliblymarked and securely fixed in an unobtrusive butobvious position within the building such as:

a. next to the electricity consumer unit; or

b. next to the chimneyorhearthdescribed; or

c. next to the water supply stop-cock.

1.59 For chimneyproducts whose performancecharacteristics have been assessed inaccordance with a European Standard (EN) andwhich are supplied or marked with a designation,the installer may optionally include thisdesignationon the label as shown in Diagram 16.

Access to combustion appliances

for maintenance

1.60 There should be a permanent means ofsafe access to appliances for maintenance. Roofspace installations of gas-fired appliances shouldcomply with the requirements of BS 6798:2009.

Diagram 16 Example notice plate for hearths and flues



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Air supply to appliances

2.1 A way of meeting the requirement wouldbe to adopt the general guidance given inSection 1, beginning at Paragraph 1.2, inconjunction with the guidance below.