Thicker insulation in a thinner space?
 

Hey guys, we were wondering if it is ok to put, lets say a 9"-10" thick insulation in a 6" space? Is it ok to pack it down to make it fit in there? Are there any pros or cons to doing this?

Thanks.

It decreases the insulating performance to compress it. Don't do it!

Hello, No not a good idea. Insulation is made to work when it is "fluffed" in the space. Compacted or compressed insulation reduces the R-value rating. Always check manufacturers recommendations. ;)

Good to know! Thanks very much for your help guys. Much appreciated.:)

No problem, you're welcome. If you are looking to gain more R-value, you can use Polystyrene hard foam in the cavity, then make up the different with fiberglass. Polystyrene hard foam comes in sizes from 1/2" all the way up to 2". This way you can place 2" foam board then 3-1/2" of fiberglass. This will fill a typical 2x6" wall. (5-1/2" cavity) and so on for floor joists etc. Hope this helps. Just a thought!;)