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Jeffrey Souder Posted: Sep 17, 2007 01:45 AM	Plenum Rating Mason, I have a customer that would like a plenum area sprayed and states he needs documentation that the foam and coatings would be plenum rated. I know that wiring used in a plenum space must be rated as such, but how about foams and intumiscent coatings??
mason Posted: Sep 17, 2007 09:57 AM	Section 2603.7 IBC building code "Foam Plastic insulation may not be used as an interior wall or ceiling finish in plenums except as permitted in Section 2604 (plastic trim) or when protected by a thermal barrier in accordance with Section 2603.4 (Tested in accordance with ASTM E 119 or assemblies FM 4880, UL 1040, NFPA 286 or UL 1715. )" In other words, a thermal barrier is required not an igntion barrier or intumescent coating.
Gary Galloway Posted: Oct 21, 2007 06:07 PM	OK, So what products would qualify as a termal barrier ??? The only thing I can think of would be 1-1/4 inches of fire rated sheetrock which would be extermely difficult to justify. Can you give us some other ideas ???
mason Posted: Oct 21, 2007 06:27 PM	There are quite a few spray on thermal barriers such as Foamsafe, K 13, Stayflex and more. ASk your foam supplier for their recommendation.
Gary Galloway Posted: Nov 21, 2007 11:42 PM	I should carify my commit about 1.25 inch sheet rock. This is what the fire marshall here wanted as a thermal barrier as he has the idea that plenum areas need a 1 hour fire rating.
mason Posted: Nov 22, 2007 12:51 PM	The fire marshal is referring to the wall or ceiling assembly being a 1 hour fire rating. But the insulation is not considered part of the fire rated wall assembly. The section I quoted describes how foam plastic insulation in a plenum is treated. And the code defined thermal barrier is 1/2 inch gypsum wallboard, not 1.25 inches.
Gary Galloway Posted: Nov 24, 2007 09:07 PM	Unforunately one of the fire marshalls I deal with here has the idea that everthing in a plenum must be protected with a one hour fire rated product and he almost always required double layers of 5/8 inch fire rated sheetrock. You would think he owns a drywall company the way he pushes it yet he lets people build new multi-story office buildings without sprinkler systems as long as they use 2 or 3 times more sheetrock than is required by code. The only good thing is I don't do much work in his part of town.

Author

Comments

Jeffrey Souder

Posted: Sep 17, 2007 01:45 AM

Plenum Rating

Mason,
I have a customer that would like a plenum area sprayed and states he needs documentation that the foam and coatings would be plenum rated.
I know that wiring used in a plenum space must be rated as such, but how about foams and intumiscent coatings??

mason

Posted: Sep 17, 2007 09:57 AM

Section 2603.7 IBC building code
"Foam Plastic insulation may not be used as an interior wall or ceiling finish in plenums except as permitted in Section 2604 (plastic trim) or when protected by a thermal barrier in accordance with Section 2603.4 (Tested in accordance with ASTM E 119 or assemblies FM 4880, UL 1040, NFPA 286 or UL 1715. )"

In other words, a thermal barrier is required not an igntion barrier or intumescent coating.

Gary Galloway

Posted: Oct 21, 2007 06:07 PM

OK, So what products would qualify as a termal barrier ??? The only thing I can think of would be 1-1/4 inches of fire rated sheetrock which would be extermely difficult to justify. Can you give us some other ideas ???

mason

Posted: Oct 21, 2007 06:27 PM

There are quite a few spray on thermal barriers such as Foamsafe, K 13, Stayflex and more. ASk your foam supplier for their recommendation.

Gary Galloway

Posted: Nov 21, 2007 11:42 PM

I should carify my commit about 1.25 inch sheet rock. This is what the fire marshall here wanted as a thermal barrier as he has the idea that plenum areas need a 1 hour fire rating.

mason

Posted: Nov 22, 2007 12:51 PM

The fire marshal is referring to the wall or ceiling assembly being a 1 hour fire rating. But the insulation is not considered part of the fire rated wall assembly. The section I quoted describes how foam plastic insulation in a plenum is treated. And the code defined thermal barrier is 1/2 inch gypsum wallboard, not 1.25 inches.

Gary Galloway

Posted: Nov 24, 2007 09:07 PM

Unforunately one of the fire marshalls I deal with here has the idea that everthing in a plenum must be protected with a one hour fire rated product and he almost always required double layers of 5/8 inch fire rated sheetrock. You would think he owns a drywall company the way he pushes it yet he lets people build new multi-story office buildings without sprinkler systems as long as they use 2 or 3 times more sheetrock than is required by code. The only good thing is I don't do much work in his part of town.

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