Cavity wall and roof insulation and condensation

Doesn't look a bad system that one. But how do you slide the last beam, between gable end walls, onto the mounts?

But I'm not overly convinced you need to go to that much bother. The insulation value of 100 mm glass wool and 18 mm chip isn't that far from 200+ mm of glass wool. Then you have all the stuff on top. B-)

On Tuesday 25 June 2013 09:33 RobertL wrote in uk.d-i-y:

The ones I've met are happy with any net improvement on existing structures.

And why would you tell them? Unless other works are involved, I don't think any would give a rat's toss that you were doing Part L stuff.

The first 2" is really noticeable, the second 2" less so, but still very effective, the third 2" less so again, but still worth having, and so on... eventually, at 10" you don't really gain anything from having any more, unless you're determined to live in a house that only needs body heat or a candle and then you have to pay ultra careful attention to other heat loss paths, like draughts and proper sealing - of course, that brings into play the whole air-exchange business and sick house syndrome.