Forum menu
What type of insula...
 

[Closed] What type of insulation for under a flat roof?

Posts: 0
Free Member
Topic starter
 

Right then, got the plaster boarding sorted thanks to the STW experts but i've realised i'd better insulate between the flat roof joists before i board the ceiling but what to use.

The roll loft insulation is alot cheaper but will be a pain to do from below or do i go for the board stuff which is more expensive and will take a lot of cutting and fitting??

thanks DIYers


 
Posted : 20/08/2010 9:45 am
Posts: 8837
Full Member
 

AFAIK you can use either, I used the rigid and they are nasty to cut and fit so wear a mask. If you need ventilation between the insulation and whatever is above it the rigid board is probably best. I take it building control are not involved? They may want roll type insulation supported by chicken wire, something to do with fire resistance. Depends where it's going.

What do I know though, I'm a DIYer in way over my head.


 
Posted : 20/08/2010 9:59 am
Posts: 0
Free Member
 

90mm of celotex or similar, gives the same R value (insulation effectiveness) as 150mm of rockwool, but is about 4 times the price per m squared.

I'd go with the board stuff.

http://www.roofingsuperstore.co.uk/product/insulation-2/insulation/celotex-ga3090-zero-odp-rigid-insulation-board-90mm-x-1200mm-x-2400mm.html


 
Posted : 20/08/2010 10:00 am
Posts: 41395
Free Member
 

I used the fluffy roll stuff. It seems to be working, no problems after all of a year!


 
Posted : 20/08/2010 10:06 am
 teef
Posts: 0
Free Member
 aP
Posts: 681
Free Member
 

That airtec stuff isn't a product I'd ever consider using- maybe in a campervan not in a house.


 
Posted : 20/08/2010 10:40 am
 teef
Posts: 0
Free Member
 

That airtec stuff isn't a product I'd ever consider using- maybe in a campervan not in a house.

Why not?


 
Posted : 20/08/2010 11:03 am
Posts: 0
Free Member
Topic starter
 

thanks all, i've gone for roll to save some cash!


 
Posted : 20/08/2010 12:02 pm