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andy buff Posted: Oct 16, 2007 07:31 AM	attics If I'M spraying to to the bottem of roof deck or to the top of sheetrock in a attic with no mechanicals up there do i need to have a ignition barrier or thermal barrier? if so whats the best way to get it.or are there any foams rated for left as is or uncovered in an attic.open or closed cell.
mason Posted: Oct 16, 2007 08:05 AM	Skinny, Even if there is no mechanical equipment, there probably are electrically wires or cable wires. The basic rule, if you have a hatch that can acces the attic you need an ignition barrier. Some sprayfoams have evaluation reports based on passing the SWRI attic and crawl space test which allow the use of intumescent paints (of a specific kind with a specific foam) and in some cases bare foam (in very specific applications). There is some concern of the use of this test for evaluating the use of foam plastics in attics and the foam plastic industry is developing a task group to look at this test and to determine if another procedure would be a better way to go. The bottom line is they want to know what is safe and how do you determine it. There seems to be a consensus that the SWRI attic and crawl space test will be replaced by something new eventually. IN the meantime, the evaluation reports produced by using the SWRI test procedures are valid until the something new takes it place. (according to ICC Evaluation Services staff, Michael Beaton) Hope this helps. Check out SPFA's Thermal Barrier Paper AY 126 for more details on thermal and ignition barriers and where and when to use them.
Dave Strnad Posted: Oct 16, 2007 03:56 PM	What is the standard in the real world concerning ignition barriers and attics? Locally nobody is enforcing this, if they were the added cost of the ignition barrier would price spf out of all but the highest end of the residential market. Depending on how you interpret it, if you are in the attic spraying then there is an attic access so all applications would require it.
mason Posted: Oct 17, 2007 07:55 AM	Dave, Yes, a code official typically will require an ignition barrier in all attics. You will get the same answer if you ask the ICC staff. As for real world, This is a litigious society. If a fire is started in the attic from any cause and the foam is not covered or an evaluation report does not exist that demonstrates that the ignition barrier is not required, the contractor and the supplier can and probably will be sued and probably will lose. An owner will pay if they recognize the need. For example, I payed an extra $850 to get cellulose installed over the sprayfoam in my attic a couple of years ago.
Dave Strnad Posted: Oct 17, 2007 09:16 AM	Mason, I did not realize that cellulose could be used. It was my understanding that one of the ignition barrier paints would still have to be used. In most applications that is how it is installed anyways. I have only called one company on the paints, but the receptionist said it ran about $.70 sqft of coverage and you needed 2 coats to get the rating. $1.40 sqft + shipping + Labor = alot of money on a 2500 sgft house. So will any cellulose work, or does it have to be K-13 or comparable? How many inches? I suppose I was misunderstanding. I thought that the ignition barrier paint was still needed and some agencies are inforcing minimum r-values so a typically job would be 4" spf, ignition barrier, then cellulose or fiber glass to get actual labled R-value minumums. Also if the access truly is covered, say drywalled and taped back up would that be ok?
mason Posted: Oct 21, 2007 10:12 AM	Dave, You require a fire rated cellulose and that is what I used in the attic. I did use K 13. Intumescent paints are not considered ignition barriers by the codes. They must be tested and approved with the specific foam in order to accepted. If you cannot access the attic, it would be considered differently and may not require an ignition barrier. (I'll doublecheck with the ICC question line for verification)

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Comments

andy buff

Posted: Oct 16, 2007 07:31 AM

attics

If I'M spraying to to the bottem of roof deck or to the top of sheetrock in a attic with no mechanicals up there do i need to have a ignition barrier or thermal barrier? if so whats the best way to get it.or are there any foams rated for left as is or uncovered in an attic.open or closed cell.

mason

Posted: Oct 16, 2007 08:05 AM

Skinny,

Even if there is no mechanical equipment, there probably are electrically wires or cable wires. The basic rule, if you have a hatch that can acces the attic you need an ignition barrier. Some sprayfoams have evaluation reports based on passing the SWRI attic and crawl space test which allow the use of intumescent paints (of a specific kind with a specific foam) and in some cases bare foam (in very specific applications).

There is some concern of the use of this test for evaluating the use of foam plastics in attics and the foam plastic industry is developing a task group to look at this test and to determine if another procedure would be a better way to go. The bottom line is they want to know what is safe and how do you determine it.

There seems to be a consensus that the SWRI attic and crawl space test will be replaced by something new eventually.

IN the meantime, the evaluation reports produced by using the SWRI test procedures are valid until the something new takes it place. (according to ICC Evaluation Services staff, Michael Beaton)

Hope this helps. Check out SPFA's Thermal Barrier Paper AY 126 for more details on thermal and ignition barriers and where and when to use them.

Dave Strnad

Posted: Oct 16, 2007 03:56 PM

What is the standard in the real world concerning ignition barriers and attics?
Locally nobody is enforcing this, if they were the added cost of the ignition barrier would price spf out of all but the highest end of the residential market. Depending on how you interpret it, if you are in the attic spraying then there is an attic access so all applications would require it.

mason

Posted: Oct 17, 2007 07:55 AM

Dave,

Yes, a code official typically will require an ignition barrier in all attics. You will get the same answer if you ask the ICC staff.

As for real world, This is a litigious society. If a fire is started in the attic from any cause and the foam is not covered or an evaluation report does not exist that demonstrates that the ignition barrier is not required, the contractor and the supplier can and probably will be sued and probably will lose.

An owner will pay if they recognize the need. For example, I payed an extra $850 to get cellulose installed over the sprayfoam in my attic a couple of years ago.

Dave Strnad

Posted: Oct 17, 2007 09:16 AM

Mason,

I did not realize that cellulose could be used. It was my understanding that one of the ignition barrier paints would still have to be used. In most applications that is how it is installed anyways. I have only called one company on the paints, but the receptionist said it ran about $.70 sqft of coverage and you needed 2 coats to get the rating. $1.40 sqft + shipping + Labor = alot of money on a 2500 sgft house. So will any cellulose work, or does it have to be K-13 or comparable? How many inches? I suppose I was misunderstanding. I thought that the ignition barrier paint was still needed and some agencies are inforcing minimum r-values so a typically job would be 4" spf, ignition barrier, then cellulose or fiber glass to get actual labled R-value minumums. Also if the access truly is covered, say drywalled and taped back up would that be ok?

mason

Posted: Oct 21, 2007 10:12 AM

Dave,

You require a fire rated cellulose and that is what I used in the attic. I did use K 13.

Intumescent paints are not considered ignition barriers by the codes. They must be tested and approved with the specific foam in order to accepted.

If you cannot access the attic, it would be considered differently and may not require an ignition barrier. (I'll doublecheck with the ICC question line for verification)

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