What is a Fire cavity barrier?

[Tyrone Thompson]

So I’m doing a loft conversion and extension on my 2 bed bungalow, the building regs notes asks for “fire resistant cavity barriers to be installed at tops of wall and gable end walls”

anyone know what these look like? And can provide me with a link to the ones I need? It’s a full fill cavity insulation job

 

[Deleted member 174758]

Whilst I'm not a brickie, I've installed Tenmat fire cavity barriers on a few jobs in recent years where we needed to provide fire breaks in the cavity formed between the building outer skin and cedar or Corian cladding. They look like this and are often (in our case) installed vertically, although bigger jobs sometimes call for horizontal installations:

They're often some form of mineral wool or mineral wool batting encased in an intumescent "skin"

 

[Tyrone Thompson]

Thanks for the response, can’t really see how it’s needed for my house, maybe apart from the adjoining gable wall, I have a rear dormer with cladding but the fire wouldn’t be spreading to another premises.

 

[Deleted member 174758]

Across the tops of the clad wall(s) between the cladding and the wall in order to stop fire spreading up the cavity and into the roof space?