Cavity closures - around windows and tops of walls?

[shabbaranks]

Hi

Had Billy building control here the other day and one of his comments was cavity closures. He didn't stipulate if he meant around the windows and doors cavity or this as well as on the top of the cavity wall.

Do you need to do the lot? The reason I ask is Im sure my bungalow doesn't have any closures on the cavity walls (not that I can see anyway). Im not a builder just a labourer and someone thats interested in learning

Thanks guys

 

[denso13]

Ask Billy? It's hard to second guess what he was meaning but he may be happy to explain further?

 

[shabbaranks]

Looked through the plans and that shows all cavity closures are required on the walls and windows so thats what I'll do.

Are they are requirement though? Like I say when we built in the current external wall of our place the cavities didn't look closed to me (1986 build)

 

[SpecialK]

I asked my BC this question a week ago. He doesn't require me to close the cavity at the top of the walls only around the door and window openings... Perhaps your building design is different?

 

[tony1851]

He doesn't require me to close the cavity at the top of the walls

The main reason the fire at Grenfell spread so quickly across the facade was the poorly-fitting cavity closers in the external cladding.

Under Building Regs, cavities are supposed to be closed at window- and door reveals, and at the tops of cavity walls. Your inspector needs to read up his Approved Doc. B.

 

[SpecialK]

5.19 Close cavity at top of wall (unless cavity is totally filled with insulation)

Seems I don't need them at the top as its a fully filled cavity...

He doesn't require me to close the cavity at the top of the walls

The main reason the fire at Grenfell spread so quickly across the facade was the poorly-fitting cavity closers in the external cladding.

Under Building Regs, cavities are supposed to be closed at window- and door reveals, and at the tops of cavity walls. Your inspector needs to read up his Approved Doc. B.

 

[^woody^]

Insulation at the top of a cavity should run continuous with the roof insulation.

At reveals, cavities should be closed but that does not mean that cavity closers must be used.