Glass-clad high-rises are the signature of modern architecture. But aluminum composite panels (ACM) behind the glass can spread fire rapidly up the facade. The 2017 Grenfell (London) and 2009 Mumbai Taj are two extreme examples. NFPA 285 defines a full-scale fire test for facade composite systems. Here we cover the test procedure, risk analysis and emerging regulation in Turkey.
Curtain Wall Anatomy
A typical curtain wall system:
- Outer skin: Tempered glass or ACM (aluminum composite material)
- Air cavity: 25-100 mm (capillary drainage)
- Insulation: PIR, PUR, MW (mineral wool) or EPS
- Inner wall: Concrete or light steel framing
Critical question: can these layers spread fire faster than the building can evacuate?
NFPA 285 Test Procedure
Full-scale fire test conducted on a two-story mock-up:
- Lower level burn room — 35 MW fire simulation
- Upper level has window opening — flames exit here
- 30-minute test duration
- Pass criteria: flames do not spread >4 m above the lower window; interior surface temperature stays below 500 C; facade does not detach
ACM Risk Assessment
Two core types in aluminum composite panels:
- PE (polyethylene) core: Cheap, combustible, rapidly spreading. Used at Grenfell. Fails NFPA 285.
- FR (fire-retardant) or MW core: Non-combustible, slow spread. Passes NFPA 285.
Cost difference is 15-30% per m2 — critical for fire safety.
Post-Grenfell Changes
The June 2017 Grenfell Tower fire (72 dead) triggered bans on PE-core ACM across the US, UK and EU:
- UK: combustible cladding banned on 18m+ buildings from 2018
- EU: CPR A2/B-s1,d0 minimum
- USA: IBC 2021 mandates NFPA 285; many states add restrictions
- Australia: ACM removal programs initiated
Turkey Status
Turkey's BYKHY regulation Article 27 addresses facade fire safety indirectly. No NFPA 285-style full-scale test mandate yet. TSE EN 13501-1 Class A1/A2 is the practical baseline. Bare PE ACM is still seen on projects; insurers flag such buildings as 'high risk' with elevated premiums.
For the Mechanical Engineer
- Request insulation certification (A2/B-s1,d0 class) when facade documents arrive
- Watch sprinkler proximity to outer facade — no protrusion through windows
- Smoke exhaust must work during facade fires (positive pressure)
- Firestops between floors inside the facade are architect's responsibility — verify anyway
Facade sprinkler analysis with SprinkCalc
Exterior sprinkler layout, deluge curtain design and fire-rated system integration.
Learn MorePrimary reference: NFPA 285 - Standard Fire Test Method. Grenfell Tower Inquiry reports are also critical. NFPA official: NFPA 285.