Hardware Designs for High Rise Facades
BES Technical Sharing -Issue 9 (July 20) Copyright@BEShttps://www.besconsultants.net
Mumbai News publish from “Mid-day” dt. June 20
Background
Generation demand for High rise buildings andhigh living luxury residentials developments hasdriven huge demand for new breed of buildingdevelopments and New designs often have noprecedents. We focus on residential high risebuildings which face unique challenges of manydifferent types of openings as per user demands.For the last 10 years or so, high rise developmentswith multi-functional requirements have posedgreat challenges. However the solutions foroperable have not been able to tackle the fast facedrequirements. This has resulted in less time tocreate new solutions and often designs usedsomewhere else are adopted.
Unfortunately we have been witnessing failures ofoperable in high rise which poses greater safetyrisks for both occupants and the public.
How is this done - ElsewhereMany parts of Asian countries enjoy comfortableweather for considerable period of the year.Hence large openings, natural ventilations are keyrequirements of building facades. Other regionsface extreme hot or Cold climates where inoperable may not be key design features. Forexample in European region, high riseresidentials generally have sealed envelopes withlimited operable or ventilated facades. Our regionrequires new design solutions, hence importeddesign solutions from other regions may not workunless local challenges are well thought of.
Lead to failure
Failure Analysis
Big difference in hardware strength, ie,.test condition Vs actual site condition.Hence we can’t just check weight capacity alone. Reliability is non linearlyreduced due to workmanship defects as explained in the graph
FailureAnalysis
Size & typeof Opening
Oversized - Not understandinghardware limitations
Hardware not upgraded
Wind effects -ignored
Safety compromiseddue to visual
Ease of operationsignored
Design
In appropriate
Light duty used at Extreme conditions
Mixed solutions -sold by Marketing
Hardware supplier-not aware of application
No secondary checks
No allowance for tolerances
Poor integration
Extrusions not compatiblewith hardware
Rely on packings for fixing
Hardware vendor notverified application
pick and choosefor cost cutting
Workmanship
Lack of skills
Site fixed -with parts missing
Fixings not robust
Mis aligned sashes
Sash fabricationsExceed tolerances
No protection-Site damaged
FailureAnalysis - 18/07/20- Mindjet
Hardware Designs for High Rise Facades
BES Technical Sharing -Issue 9 (July 20) Copyright@BEShttps://www.besconsultants.net
Local requirements, often very different
Requirements vary within regions, for example Singapore highrises(residential / commercial) do not require openings other than FireAccess Panels,. Whereas Indian building code (NBC) recommends10% facades to have operable for smoke and fire evacuation purposes.Hence these provisions on high rise buildings which experience highwind pressures need robust operable hardware solutions. Designingopenings in highrises requires good integration all the way fromdesign to implementation. Often sizes and design requirements arenot the same, hence every building requires skills and experiences tosafely design the operable with the right hardware.
I am using the best Internationalbrand -Why should I bother ?
Hardware is generally restricted to ahandful of international brands whichhave good track records. Howeverpremium brands do not guaranteetheir designs for local challenges. Justrelying on brand value alone may notbe adequate to take care of designsafety. We have witnessed severalfailures which have used premiumbranded hardware.
Unfortunately there is no one- stopsolution for façade integrated operable,for example a brand who makes handleand locks does not necessarily haverobust reliable stay arms. Thereforejust relying on a supplier team, withtheir commercial interest to sell theirown products may not be the bestsolution.
Due to these challenging requirements,pick and choose approach may workbetter with proper integration andassembly which may yield best ofeverything. However these requiredeeper involvement of façadedesigners, good experiences, deepintegration techniques, co-ordinations,etc,.
Comparison of typical Casement application
Typical Use Medium duty Heavy Duty
Std. sash with SGU/DGUglass, for low / medium ht.
Large sash with DGUglass, medium rise
Large sash with DGU glass,high rise
Just adding more light duty hinges in place of heavy duty hinges isNOT a safe solution. Heavy duty hinges have different fixing methodswhich reduces risk for challenging applications., Likewise whole rangeof components, not just a single component is to be given adequateattentions so that overall hardware system becomes reliable and safe.
Image : Sash failure due topoor fixing of stay arms
Typical Defects lead to failures such as hardware not integrated withextrusions, not engaged with Euro grooves, rattling of sashes due topoor fixings. Extrusions are some times not compatible for all types ofhardware, as a quick fix solution hardware is fixed with packing andshims which compromises safety.
Typical Defects
Hardware Designs for High Rise Facades
BES Technical Sharing -Issue 9 (July 20) Copyright@BEShttps://www.besconsultants.net
Prevention
Some key aspects are presented here as good design and implementationapproach.
Resolved design : Design and finalise hardware at thedesign stage, don’t leave it to fabrication stage. Sample of BESdrawing of pre-construction stage shows hardware details.
Skills and dedication are essential to avoid any failures.Wide Knowledge Not Limited to any brand, ratherfamiliar with availabilityDedicate Check in details, not to rely only based onsupplier’s dataTolerances Don’t just check weight capacity, considerimperfections and tolerances.Fabrication Knowledge Familiar with fabricationand fixing methods.Check and Verify Not just rely on drawings, test anddemonstrate at shop floor
Essential Skills
Hardware- Safe use
Type of opening
Choose as per functions
Residential
Commercial
Size of Opening
Mindful of size
Large sizes - cost more + safety risk
High rises - Limit the sizes - samesizes of low rise not essential
Impact of wind
Rattling due to poor fix
Rattling lead to fatigue failure
Smashing -heavywind
Safety
Allow restricted opening - use restrictor
Hinges or stay arms
Use appropriate size and numbers
Be aware of standard Vs Heavy duty type
Lock points engage while shut
Make it child safe
IntegrationWith facades
Extrusions to suit hardware
Avoid rely on packings for fixing
Careful with screws - use Pan Head
Local stiffening needed - min.Frame thickness use 2.5 mm
Capacity -not just weight of sashConsider tolerances
- Safe use - 19/07/20- Mindjet
Web version (with Videos) of thiswrite-up available here
Highrise facades hardware design