On Tue, 22 Dec 2009 23:21:31 +0000, "george [dicegeorge]"
wrote:

Watching Holmes on Homes tuesday evening on a Shed channel
he was fixing some freezing plumbing which had been half insulated
with what he called 'half pound foam'
(which I guess is the expanding foam we get here in cans).
He said in cold weather it shrinks and creates gap through which cold
air can flow.
He coated it with a blue foam, which he called 'Two pound foam'.
What is this stuff?

http://wiki.diyfaq.org.uk/index.php?...Expanding_Foam
does not help.

[g]


The two most commonly used spray foam products are low-density,
open-cell SPF (nominally referred to as “1/2 pound”) and
medium-density, closed-cell foam (“2 pound”). Foametix offers both
types of SPF, dubbed Blue Max 050 Open-cell and Blue Max 200
Closed-cell.