Foam vs Fiberglass

[cem-bsee]

what do you think the word 'ALL' includes | excludes???

[bobb25]

no-
the secret to ALL insulation is the entrapment of air -- then having small pockets of air to prevent transfer by convection

if you crush the fiberglass bats, you change the R value!

Silly me, I always thought air (or gas or liquid) facilitated the convection process. I never knew air prevented or slowed the convection process. I always thought air only slowed or prevented the conduction process.

what do you think the word 'ALL' includes | excludes???

So how much air is actually inside spray foam?

[Waterloo]

Studs are pretty good as I framed everying myself. The lumber that came from Lowes was excellent. Very, very straight lumber. Was kinda unbelieveable

Who did you pay off for that? Seems any board I get from HD or Lowes is for building round houses with curved walls.

[bobb25]

Who did you pay off for that? Seems any board I get from HD or Lowes is for building round houses with curved walls.

That's pretty funny, actually I found the same thing as jayman did. My Lowes sells pretty straight 2 x 4s.

[jaymay75]

Home Depot lumber is absolute crap. But the Lowes lumber that we get around here is amazing good. (Pittsburgh) I framed my whole house and maybe threw away 2 2x6's. The floor joists were awesome. Dead on straight and no bows.

was pretty shocked.

[jaymay75]

BTW - My lowes rents a tow behind blower that is pretty commercial. I've decided to do the cellulose insulation everywhere and do it myself.

I'm either going to cheesecloth the walls and blow it in, or hang the drywall nad then blow it in.

I was quoted $4k for Cellulose insulation around here, which is insane.

I'll do it myself for about $800

[drcustom]

So how much air is actually inside spray foam?

Millions and millions of tiny little bubbles no? Taking together, there's quite a bit actually. Although the gas isn't atmospheric air, the principal of resistance to thermal migration is the same.