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Adam Beazley Posted: Aug 11, 2010 03:32 PM	Thermal Barrier or ignition barrier or both? Ok my questions relates to how the IBC 2009 reads. We are looking at putting a open cell spray foam in a commercial building here is Louisiana. I am having trouble understanding exactly what the code is saying. Which is true? You must have a thermal barrier (1/2" gyp) between the foam and interior air conditions space ALWAYS? Or does that thermal barrier get cancelled out in the attic where you can substitute an ignition barrier? In other words, lets say I have a gyp board ceiling, do I NEED an ignition barrier as well? If I choose a non rated acoustical tile drop ceiling, do i need an ignition barrier or a thermal barrier on the foam? What happens in those situations?
Posted: Aug 11, 2010 04:04 PM	Adam, Excellent questions. You bring out issues that can get tricky. Here's the way I suggest to look a this: You MUST have a Thermal Barrier between the foam and the interior of any "occupied space". Whether it is air conditioned does not enter into it. Think of Thermal Barrier requirments as purely based upon the protection of occupants. As I outlined in other discussions, it is to keep the foam from reaching flash over in a fire event, buying time for occupants to get out. In the next part of your question, to ask if Thermal Barriers are "cancelled out" where Ignition Barriers are used can get confusing. It would be more correct to keep the two separate. I would answer by simply saying that, in attics, an Ignition Barrier meets the code requirements. A Thermal Barrier is not required there. The confusion typically comes from the idea that these two requirements are very closely related, when in fact they are worlds apart. The similar test methods give this impression to some. When you ask if they "substitute" for each other, it can confuse your view of these codes. They are two completely separate issues. As for your "specific" questons: If you have a 1/2" gyp board ceiling it is a qualified Thermal Barrier. You didn'y say whether it was a ceiling in the attic or in the "occupied" space, BUT the answer is the same for both. If it is in the interior, there is no Ignition Barrier requirement there... the code calls for Thermal BArrier which you have satisfied with the gyp goard. If it is an attic, there is ONLY an Ignition Barrier requirement there. The Thermal Barrier material (gyp board) is "superior" in fire performance to an ignition barrier, and therefore will satisy the requirement for an Ignition Barrier. NO, you won't have to put an Ignition Barrier over the Thermal Barrier! The codes do not force you to provide "double coverage" in this case, but allows for the fact that you have exceeded the requirement, and thus just the gyp board is code compliant. In the example of the accoustical tile drop ceiling (interior space), you must provide a Thermal Barrier between the foam and the space. As far as the Thermal Barrier requirement goes, you should picture this as if the drop ceiling were not there. The requirement is not changed by any drop ceiling unless someone has one tested as a Thermal Barrier. I hope this helps. If I left any gray areas, let me know and I'll try to clear the picture further. Good luck on your job! Mike Kiser
Adam Beazley Posted: Aug 11, 2010 06:03 PM	Thanks Mike, I think i have it now: 1: Put 1/2" gyp as the ceiling in the conditioned space, no ignition barrier required in the attic for the 2 products i am looking at because of their ICC-ES report. 2: If I use a non rated drop ceiling, then I will need a thermal barrier somewhere between the conditioned space and the foam at the pitched roof. 3: If i can find an acoustical tile ceiling which is fire rated for at least 15 minutes, that would serve as my thermal barrier and I wouldn't need an ignition barrier. Please correct me if any of the above is not true. Now that leads me to the next question. Wouldn't a typical 1 hour drop ceiling system from say Armstrong meet the requirements of the thermal barrier? Of would that be overkill? Could a smoke tight ceiling tile system (weight is over 1 lb) meet that requirement? Would I just have to have the ASTM E 119 test results and show that it will last 15 minutes?
Adam Beazley Posted: Aug 13, 2010 01:36 PM	Ok so here is our verdict: We found that Icyneen had and ICC-ES report which allows the foam to be unprotected in the attic space as long as we have a 1/2" gypsum board (or equal) at the ceiling. So its cheaper to put up a gyp-board ceiling ($0.88/sf) than to spray a TB coating in the attic ($1.50/sf)and leave off the 1/2" gyp-board ceiling. Then we will just hang the Acoustical tile ceiling 6" to 8" below the gypsum board. Problem solved... case closed. Thanks for the help!
Posted: Aug 13, 2010 05:58 PM	adam,, the rock will require minimum 1 layer of tape and mud at the seams as well for tb rating...so just a little more material and labor to factor in,,, 'dude
Posted: Aug 15, 2010 09:36 PM	Adam, You are essentially correct on all points. Even though a 1 hour ceiling tile is overkill, it will nonetheless satisfy the Thermal Barrier requirement. Just be careful that you install the ceiling in the manner "as tested" in the ASTM E119 report. Example: As foamdude notes in his answer, if specific taping is required (or any other installation specifics), you must abide by them to keep the qualifications. You mentioned a smoke tight ceiling tile, which implies installation techniques that are probably very specific, so, again, be careful to be precise in your methods. As I noted on the other thread, the code calls for ANY material that has a ASTM E119 rating of 15 minutes or greater, so YES if you find a ceiling system that has a one hour rating, just present that information to the codes official, and he will approve it for thermal barrier. He MIGHT ask for the test, so have it handy. If he does NOT approve it, ask why and put that information in an inquiry on this forum. I'll help you with it. Best of luck. Mike Kiser
Adam Beazley Posted: Aug 16, 2010 09:01 AM	Well, actually the Acoustical Tile ceiling will not work. I have not found one that can double as a thermal barrier, even the fire guard ones. Basically those have only been tested in a full ceiling/deck assembly with concrete deck, they have NOT been tested by themselves. So I will have to use the 1/2" gypsum board ceilings.
Posted: Aug 16, 2010 01:37 PM	Adam, Sorry to hear that. I was hoping someone had tested something as a "stand-alone" material. When I get back to the office (still on the road) and I start researching alternative sheet (or other) materials that I can recommend as sheetrock alternatives, which have "tested" E119 ratings of 15+ minutes, I will see if anyone knows of a ceilng tile in that category. This is actually a good example of someone (you) knowing how to interpret a test. This is very similar to my discussion on the other thread (Thermal Barriers - Clarifying the "perceptions"). That was about how to properly interpret tests of coatings on foam, where temperatures are read on the back side of the entire wall assembly. Just like your case with a tile using a concrete deck as part of the "tested" design, a coating tested as described above becomes only "part" of an assembly which is the actual TESTED "Thermal Barrier". Big difference. Sorry, can't help myself, but I think every example that helps clarify these points should be discussed, hopefully to the benefit of someone reading this who might need more clarification on the point. I'll get back with you soon with what I find in "tiles". Mike Kiser

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Adam Beazley

Posted: Aug 11, 2010 03:32 PM

Thermal Barrier or ignition barrier or both?

Ok my questions relates to how the IBC 2009 reads.

We are looking at putting a open cell spray foam in a commercial building here is Louisiana. I am having trouble understanding exactly what the code is saying.

Which is true? You must have a thermal barrier (1/2" gyp) between the foam and interior air conditions space ALWAYS? Or does that thermal barrier get cancelled out in the attic where you can substitute an ignition barrier?

In other words, lets say I have a gyp board ceiling, do I NEED an ignition barrier as well?
If I choose a non rated acoustical tile drop ceiling, do i need an ignition barrier or a thermal barrier on the foam?

What happens in those situations?

Posted: Aug 11, 2010 04:04 PM

Adam,

Excellent questions. You bring out issues that can get tricky. Here's the way I suggest to look a this:

You MUST have a Thermal Barrier between the foam and the interior of any "occupied space". Whether it is air conditioned does not enter into it. Think of Thermal Barrier requirments as purely based upon the protection of occupants. As I outlined in other discussions, it is to keep the foam from reaching flash over in a fire event, buying time for occupants to get out.

In the next part of your question, to ask if Thermal Barriers are "cancelled out" where Ignition Barriers are used can get confusing.

It would be more correct to keep the two separate. I would answer by simply saying that, in attics, an Ignition Barrier meets the code requirements. A Thermal Barrier is not required there.

The confusion typically comes from the idea that these two requirements are very closely related, when in fact they are worlds apart. The similar test methods give this impression to some. When you ask if they "substitute" for each other, it can confuse your view of these codes. They are two completely separate issues.

As for your "specific" questons:

If you have a 1/2" gyp board ceiling it is a qualified Thermal Barrier. You didn'y say whether it was a ceiling in the attic or in the "occupied" space, BUT the answer is the same for both. If it is in the interior, there is no Ignition Barrier requirement there... the code calls for Thermal BArrier which you have satisfied with the gyp goard.

If it is an attic, there is ONLY an Ignition Barrier requirement there. The Thermal Barrier material (gyp board) is "superior" in fire performance to an ignition barrier, and therefore will satisy the requirement for an Ignition Barrier. NO, you won't have to put an Ignition Barrier over the Thermal Barrier! The codes do not force you to provide "double coverage" in this case, but allows for the fact that you have exceeded the requirement, and thus just the gyp board is code compliant.

In the example of the accoustical tile drop ceiling (interior space), you must provide a Thermal Barrier between the foam and the space. As far as the Thermal Barrier requirement goes, you should picture this as if the drop ceiling were not there. The requirement is not changed by any drop ceiling unless someone has one tested as a Thermal Barrier.

I hope this helps. If I left any gray areas, let me know and I'll try to clear the picture further.

Good luck on your job!

Mike Kiser

Adam Beazley

Posted: Aug 11, 2010 06:03 PM

Thanks Mike,

I think i have it now:

1: Put 1/2" gyp as the ceiling in the conditioned space, no ignition barrier required in the attic for the 2 products i am looking at because of their ICC-ES report.

2: If I use a non rated drop ceiling, then I will need a thermal barrier somewhere between the conditioned space and the foam at the pitched roof.

3: If i can find an acoustical tile ceiling which is fire rated for at least 15 minutes, that would serve as my thermal barrier and I wouldn't need an ignition barrier.

Please correct me if any of the above is not true.

Now that leads me to the next question. Wouldn't a typical 1 hour drop ceiling system from say Armstrong meet the requirements of the thermal barrier? Of would that be overkill? Could a smoke tight ceiling tile system (weight is over 1 lb) meet that requirement? Would I just have to have the ASTM E 119 test results and show that it will last 15 minutes?

Adam Beazley

Posted: Aug 13, 2010 01:36 PM

Ok so here is our verdict:

We found that Icyneen had and ICC-ES report which allows the foam to be unprotected in the attic space as long as we have a 1/2" gypsum board (or equal) at the ceiling. So its cheaper to put up a gyp-board ceiling ($0.88/sf) than to spray a TB coating in the attic ($1.50/sf)and leave off the 1/2" gyp-board ceiling. Then we will just hang the Acoustical tile ceiling 6" to 8" below the gypsum board.

Problem solved... case closed. Thanks for the help!

Posted: Aug 13, 2010 05:58 PM

adam,,
the rock will require minimum 1 layer of tape and mud at the seams as well for tb rating...so just a little more material and labor to factor in,,,
'dude

Posted: Aug 15, 2010 09:36 PM

Adam,

You are essentially correct on all points. Even though a 1 hour ceiling tile is overkill, it will nonetheless satisfy the Thermal Barrier requirement. Just be careful that you install the ceiling in the manner "as tested" in the ASTM E119 report. Example: As foamdude notes in his answer, if specific taping is required (or any other installation specifics), you must abide by them to keep the qualifications.

You mentioned a smoke tight ceiling tile, which implies installation techniques that are probably very specific, so, again, be careful to be precise in your methods.

As I noted on the other thread, the code calls for ANY material that has a ASTM E119 rating of 15 minutes or greater, so YES if you find a ceiling system that has a one hour rating, just present that information to the codes official, and he will approve it for thermal barrier. He MIGHT ask for the test, so have it handy.

If he does NOT approve it, ask why and put that information in an inquiry on this forum. I'll help you with it.

Best of luck.

Mike Kiser

Adam Beazley

Posted: Aug 16, 2010 09:01 AM

Well, actually the Acoustical Tile ceiling will not work. I have not found one that can double as a thermal barrier, even the fire guard ones. Basically those have only been tested in a full ceiling/deck assembly with concrete deck, they have NOT been tested by themselves.

So I will have to use the 1/2" gypsum board ceilings.

Posted: Aug 16, 2010 01:37 PM

Adam,

Sorry to hear that. I was hoping someone had tested something as a "stand-alone" material. When I get back to the office (still on the road) and I start researching alternative sheet (or other) materials that I can recommend as sheetrock alternatives, which have "tested" E119 ratings of 15+ minutes, I will see if anyone knows of a ceilng tile in that category.

This is actually a good example of someone (you) knowing how to interpret a test. This is very similar to my discussion on the other thread (Thermal Barriers - Clarifying the "perceptions"). That was about how to properly interpret tests of coatings on foam, where temperatures are read on the back side of the entire wall assembly. Just like your case with a tile using a concrete deck as part of the "tested" design, a coating tested as described above becomes only "part" of an assembly which is the actual TESTED "Thermal Barrier". Big difference.

Sorry, can't help myself, but I think every example that helps clarify these points should be discussed, hopefully to the benefit of someone reading this who might need more clarification on the point.

I'll get back with you soon with what I find in "tiles".

Mike Kiser

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