Another insulation question......

[Jacko74]

.....sorry.

My architect is stating that my loft conversion requires 120mm celotex between the rafters, 20mm under.... Totalling 140mm.

I can get some 100mm celotex at a good (v.good) price.

Would I not be able to use 100mm between, 40mm under instead? same total.

Headrooms not an issue, plenty of space.

Also. In general, can Celotex / kingspan / xtratherm etc be mixed / used together??

Thanks in advance....

 

[freddiemercurystwin]

Yes, it may be worth getting a U value check done by Celotex, you may find you don't need the 40mm and can get away with 30 or similar. Its not normal to combine different manufacturers of insulation but that's only due to the logistics of how its purchased, I'm not aware of any compatibilty issues.

 

[Jacko74]

Cheers Freddy,

I only wonder because after looking around on the net, I can get left-overs of this, that and the other.
I know its not ideal but it will save a bob.

Am I maybe worrying too much?
If I put up 100mm - 40mm rather than 120mm - 20mm how would bc know? If it was done before they saw I mean.

 

[freddiemercurystwin]

Because they may well wanna see it as its installed as your attitude is not uncommon.

 

[geraldthehamster]

Cheers Freddy,

I only wonder because after looking around on the net, I can get left-overs of this, that and the other.
I know its not ideal but it will save a bob.

Am I maybe worrying too much?
If I put up 100mm - 40mm rather than 120mm - 20mm how would bc know? If it was done before they saw I mean.

I'd have thought 140mm would provide the required U value, either way.

Cheers
Richard