On 2005-11-05, Edwin Pawlowski wrote:

No experience with this particular products so I can't comment on
particulars. There is an optimal density for any foamed insulating
material. By going to a lower density you save lots of money and
lose very little insulating value if you look at the curves. Past
the optimum, higher density offers less insulating value and cost
much more.

Well, in two part polyurethane foams, I'm familiar with two classes of
products:

1) Open-cell, semi-rigid products with a density of 0.5 lbs/ft^3,
R-values from 3.6-4.0/inch, and perm ratings around 16 perms @ 3"
thick.

2) Closed-cell, rigid products with a density of 1.75 lbs/ft^3 and
R-values from 6.2-7.0/inch, and perm ratings around 1.26 perms @ 3"
thick.

While the material cost of the closed-cell foams must be significantly
higher, it seems like the installed cost/R-value is comparable to the
open-cell foams. Is there any disadvantage to the closed-cell
products?

Cheers, Wayne