Cutting open a bag of insulation - GIF

[G.Paul]

Mineral wool is made from slag, fiber glass is made from sand. The products contain a none detreating fiber witch will cause fibroses and one can die. the fibers are just as dangerous as asbestos. About 25 years ago the was no warning on the package now there is. A good quality mask is strongly recommended

[G.Paul]

No cellulose will not compact to less then its density unless it is exposed water

[G.Paul]

Rockwool has to lowest R-Factor of any blown in material

[nova_robotics]

Did you stop your basement insulation 16 inches from the floor?

Reasons why:

Flood damages. Will not wick water up. Most basement floods are 12 inches or less.
No gain on the insulation effects below frost level. If you are on the east coast there is not very deep frost. Prairie provinces a different story but even there the building code calls for 16" above the floor. As it also calls for vapor barrier on the exterior and the interior of the basement walls. That was a recommendation in my code which is about 18 years old. I think that became part of the national building code.

Nope. I insulated with foam right down to the concrete. My house is built into the side of a hill with very little chance of flooding. You're probably right about the frost line though. Ground temperature here considered to be 9 - 10C (for geothermal calculations). Insulating that far down probably prevents heat from entering in the winter.

[nova_robotics]

No cellulose will not compact to less then its density unless it is exposed water

I don't know about that. I put 80 bags of blown in cellulose in my garage attic about a year ago. It was right up to the plywood when we blew it in. It settled about 6" in the last year. You can see the perfect imprint of the rafters in the insulation, except now there's a big gap.

[nova_robotics]

No cellulose will not compact to less then its density unless it is exposed water

Here's a picture I just took in my shop attic. This used to be full all the way up to the plywood decking when we blew it in. The shop is 40x50 and the whole length of the shop has settled fairly evenly. That's about 6" settlement on 18-24" insulation thickness over the period of one year. Don't get me wrong, I'm still very happy with the cellulose. But it definitely settles.