cellulose insulation

cosatron

Any thought or misgivens about cellulose insulation, im over seeing a timber frame house for a client and he suggested it to me. My biggest concerns are
fire rating-warmcel have a irish agreement cert and thats about it, the distributors hadn't a clue
does it sag in time-
acheivable u-values- allot of different figures from the distributors.
thanks.

Spillane

Here's a website with some information on cellulose insulation, and it's fire rating, etc;

http://www.houleinsulation.com/fire.html

As for sagging, it depends on the method that is used for fitting the insulation. If the timber frame wall is lined with a membrane, the insulation can't be densely packed into the wall. When the insulation is fitted with this method, it will sag in time (not long either if the slabs aren't fitted soon after) and then as a result bulge the plaster board out, making the slabbers job a pain, and more importantly, it will leave a void at the top of the wall where it is uninsulated and therefore a cold bridge. This is just my experience of what I've seen, so this might not be the case every time.

A better method of fitting cellulose, is to densely pack the insulation into the wall, with the internal and external parts of the wall covered with hard surfaces, instead of having the loose membrane. Ply on the inside, and a hard breathable wood based sheeting on the external side, this keeps the insulation so dense that sagging won't occur. This is called a closed wall system and is normally pre-fitted in the factory.

Cellulose is an extremely effective insulation, as long as it's correctly fitted, and it has it's environmental advantages aswell.

Hope this helps.

Alan