Polyicinine Foam Shrinkage?

D107

Seems like it has shrunk at least 10%. I'm thinking this could affect its sealing properties over a relatively short time. I know that everything, caulking, etc. degrades over time but i was thinking of doing my attic eaves and knee walls with the stuff, but perhaps, as Constantin has pointed out, cellulose is a good alternative, except I don't think you can put that upside down under the roof eaves unless you sheetrock it in.

Also, with foam, when you tear off an old roof--as we'll have to do in five or so years--does not all the pounding and re-nailing or sheathing repairing effect the sealing properties? Maybe caulking and fiberglass is better.

Thanks,

David

Brad White_9

Interesting, David

about the shrinkage. (Insert Seinfeld episode here.)

The cellulose question, about sheetrocking? There is a facet of the NuWool system among others which uses a reinforced polyethlylene sheet behind which is blown the material. This may not apply to you whereby you might want to blow in directly. But if the joists are exposed it may be a reasonable alternative. Fire codes may trump this, but it is something in the literature to consider short of sheetrock.

My $0.02

Brad