We are just about to put in a large door and window in extension and have a question regarding cavity closers. Its a 75mm cavity with full fill Dritherm 32 insulation.
I got some cavity closers from local builder's merchant. It basically looks crap - its a thin bit of polystyrene wedged inside two bits of plastic frame which keep falling apart. I can push back the insulation and stick it in anyway but reality is that the bit of polystyrene inside is actually a worse insulator than the dritherm slab I am pushing back.
So the question is what should I do? Stick the bit of plastic in with polystyrene knowing that I am doing the right thing? Leave çavity insulation in place and just board over?
Another option I am thinking of is putting in a length of 70mm celotex insulation with length of DPC against each wall. To me, that sounds a far better job than anything else but obviously I've never done it before so what do I know.
I got some cavity closers from local builder's merchant. It basically looks crap - its a thin bit of polystyrene wedged inside two bits of plastic frame which keep falling apart. I can push back the insulation and stick it in anyway but reality is that the bit of polystyrene inside is actually a worse insulator than the dritherm slab I am pushing back.
So the question is what should I do? Stick the bit of plastic in with polystyrene knowing that I am doing the right thing? Leave çavity insulation in place and just board over?
Another option I am thinking of is putting in a length of 70mm celotex insulation with length of DPC against each wall. To me, that sounds a far better job than anything else but obviously I've never done it before so what do I know.