Grenfell Tower facade

Cross-section of the outside of Grenfell Tower, showing the materials under investigation by police

Concrete wall

of tower

Foil coating

50mm

gap

Polyethylene

3

2

1

Aluminium sheets

1 Insulation layer

Celotex RS5000 has performed well in a number of fire tests, but it is combustible. Made from polyisocyanurate (PIR), it releases toxic fumes such as hydrogen cyanide when it burns

 

2 Air gap

The air gap ensures that condensation on the building evaporates and doesn't damage the outer walls. The gap may have helped the fire spread through a ‘chimney effect’

 

3 Cladding

Reynobond panels used on Grenfell Tower sandwich a layer of polyethylene between two aluminium sheets. The panels are flammable and official building regulations recommend that only panels with non-combustible cores are used on buildings taller than 18 metres

1 Insulation layer

Celotex RS5000 has performed well in a number of fire tests, but it is combustible. Made from polyisocyanurate (PIR), it releases toxic fumes such as hydrogen cyanide when it burns

 

2 Air gap

The air gap ensures that condensation on the building evaporates and doesn't damage the outer walls. The gap may have helped the fire spread through a ‘chimney effect’

 

3 Cladding

Reynobond panels used on Grenfell Tower sandwich a layer of polyethylene between two aluminium sheets. The panels are flammable and official building regulations recommend that only panels with non-combustible cores are used on buildings taller than 18 metres

Concrete wall

of tower

Foil coating

50mm

gap

Polyethylene

3

2

1

Aluminium sheets