[bubbler]

Originally Posted by AGWhitehouse

foam burns FAST. You shouldn't mess around here, it could get you into a heap of trouble.

Absolutely agree here.

Anyone doubts this, go buy three items from a HW store:

A 2x4, a FG batt w/ paper, and a chunk of Foamular (or similar foam board).

Hold a match under each one and you'll see what a VAST difference there is in burn rate, and the smoke produced... foam is scary stuff in that regard.

[federer]

for me that begs the question- code says drywall alone is sufficient as barrier to foam. interesting

[AGWhitehouse]

Originally Posted by federer

for me that begs the question- code says drywall alone is sufficient as barrier to foam. interesting

That is plenty sufficient covering. The purpose of the ignition barrier is to delay the inevitable combustion of the product long enough to ensure that the building inhabitants can escape. Drywall is used extensively in fire rated wall assemblies and 2 layers of 5/8" type X is generally considered to give a 1-hour rating.

[federer]

oh ok cool. so that will give me enough time to grab some stuff before i leave!