bricky wants a bit of advice on an exterior wall

[bricky]

ok lads
i,m a bricky have been for a while,just like to pick a few brains as to a proven method of what i want to do


ok i,m building an extension its going up in cavity,brick and thermalite..2 skin of 4 inch..the flank wall what i want to build has to be 4 inch because of a space issue and i really dont want to do outa brickwork,coz its a major chunk....this is all about speed...far as i can see i dont have alot of options,,4 inch concretes or thermalites...i know cavity is the best as regards to moisture and damp...
has anyone built a inch liviing area wall and sealed it without a prob... i was thinking batton the wall render with a water proofer.. pitch black it then insolating or waterproof plasterboard......any comments are welcome

cheers

 

[noseall]

condensation and the subsequent mildew will be just as much of a problem as the penetrating damp. on very cold days condensation will become prevalent.

you will need to fend off rainwater to a certain degree with a waterproof render, but insulating the wall is what counts.

I'm not sure whether the foam backed boards will give you the 'u' value number that is required by b'regs but at least it will make a difference.

what has the b.c. officer/designer/architect recommended?

 

[^woody^]

You can do a timber frame to the side wall with 100mm celotex and this will be as good as the cavity wall. Plastic shiplap to the outer face.

Or you can return the outer skin, butt up the inner wall to the return (insert vDPC and 25mm polystyrene to prevent cold bridge and then dryline the inner wlll with celotex and plasterboard.

You don't need to worry about external waterproofing render, if you fix a vapour barrier/DPM to the inside of the external wall before fixing the celotex