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Marc French Posted: Apr 24, 2010 01:34 PM	Foam on ducts A building official recently stopped one of my crews from spaying 2.0 lb foam on a main supply HVAC duct. He quoted IMC code I believe re the temp possibilities of the duct being over 250 degrees ? The duct was located in a open area exposed area under a manufactured home so Im not sure it qualifies as a crawl space or outside application. Losing the ability to shoot these ducts will really hurt our efforts any suggestions.
mason Posted: Apr 24, 2010 03:23 PM	There is a conflict in the ICC codes. The IRC (residential code) specifically allows the use of SPF on ducts in attics and crawlspaces. However, the IMC (mechanical code) does not allow any insulation that does not have a 25 flame spread or less and a less than 50 smoke rating. Show them the section in the IRC that allows SPF (with a suitable ignition barrier) stressing that this is a residential construction and should go by the IRC and not the IMC (which is for commercial buildings primarily). The section is M1601.3 in Chapter 16 of the IRC "Duct coverings and linings, including adhesives where used shall have a flame spread index not higher than 25 and a smoke developed index not more than 50... Exception: Spray application of polyurethane foam to the exterior of ducts in attics and crawl spaces shall be permitted subject to all of the following: 1. The flame spread index is not greater than 25 and the smoke developed index is not greater than 450 at the installed thickness. 2. The foam plastic is protected in accordance with the ignition barrier requirements of Sections R316.5.3 and R 316.5.4 3. The foam plastic complies with the requirements of Section 316." (the foam plastics section of the IRC)
Marc French Posted: Apr 25, 2010 03:24 PM	Thanks Mason that is extremely helpful. A huge amount of our work is made up in retro-spraying ducts in attics and crawls. Up until not so long ago it really attracted no attention from building officials. We are test driving the BASF 1500 product this spring and hoping for a foam product in the future (like everyone) that will spray on bare.
Posted: Apr 25, 2010 06:56 PM	basf's 81206, spraytite 178, comfortfoam 178 and walltite brands can be applied in attics and crawls with out ignition barrier covering as per their icc-es report...es 2642 section 4.4.2 & 4.4.3...hope this helps 'dude

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Comments

Marc French

Posted: Apr 24, 2010 01:34 PM

Foam on ducts

A building official recently stopped one of my crews from spaying 2.0 lb foam on a main supply HVAC duct. He quoted IMC code I believe re the temp possibilities of the duct being over 250 degrees ? The duct was located in a open area exposed area under a manufactured home so Im not sure it qualifies as a crawl space or outside application. Losing the ability to shoot these ducts will really hurt our efforts any suggestions.

mason

Posted: Apr 24, 2010 03:23 PM

There is a conflict in the ICC codes. The IRC (residential code) specifically allows the use of SPF on ducts in attics and crawlspaces. However, the IMC (mechanical code) does not allow any insulation that does not have a 25 flame spread or less and a less than 50 smoke rating.

Show them the section in the IRC that allows SPF (with a suitable ignition barrier) stressing that this is a residential construction and should go by the IRC and not the IMC (which is for commercial buildings primarily).

The section is M1601.3 in Chapter 16 of the IRC

"Duct coverings and linings, including adhesives where used shall have a flame spread index not higher than 25 and a smoke developed index not more than 50...

Exception: Spray application of polyurethane foam to the exterior of ducts in attics and crawl spaces shall be permitted subject to all of the following:

1. The flame spread index is not greater than 25 and the smoke developed index is not greater than 450 at the installed thickness.

2. The foam plastic is protected in accordance with the ignition barrier requirements of Sections R316.5.3 and R 316.5.4

3. The foam plastic complies with the requirements of Section 316." (the foam plastics section of the IRC)

Marc French

Posted: Apr 25, 2010 03:24 PM

Thanks Mason that is extremely helpful. A huge amount of our work is made up in retro-spraying ducts in attics and crawls. Up until not so long ago it really attracted no attention from building officials. We are test driving the BASF 1500 product this spring and hoping for a foam product in the future (like everyone) that will spray on bare.

Posted: Apr 25, 2010 06:56 PM

basf's 81206, spraytite 178, comfortfoam 178 and walltite brands can be applied in attics and crawls with out ignition barrier covering as per their icc-es report...es 2642 section 4.4.2 & 4.4.3...hope this helps
'dude

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