Building regulations- cavity closures

trex227

Does anyone know what the building regulations are for cavity closing on windows? The wall itself has insulation in

- is it required to use those rigid cavity closures

- or is Celotex sufficient? If so, do you need a DPM on the outer bricks?

Thanks in advance

stuart45

You can get insulated DPC and return the blockwork,  although I always use closers now. Years ago the inner skin was returned with a strip of 6 inch DPC in the jambs. 
I have heard of people making their own closers with a roll of 6 inch DPC and gluing some Celotex to use.

theonlywayisup

Is it a timber frame or block?

stuart45

Is it full or partial fill?

trex227

Full fill and block.

stuart45

Even with full fill I still use cavity closers. I'm pretty sure, but not 100%, that the cavity has to be closed for regs. I've always just done it though without really knowing for sure. Years ago cavities were left open when box frame sliding sash windows were used, but it was returned for other types. 
You could check with your BCO if you don't want to use them.