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Foam Insulation?

B

Bama dav

Bronze Member
Joined
Jun 11, 2012
Messages
30
Location
Alabama
Just wondering how other inspectors are dealing with spray foam insulation in attic and crawl spaces.Code requires it be covered.I keep getting alot of info on spray that meets thermal and ignition barriers,but not shure it meets the requirments of the code. It seems as soon as you solve one problem you run into another.Combustion air?,Attic and crawl space ventalation? So what are you guys doing?
 
This is a typical older California attic. A couple feet of ground up newsprint makes for a great fire when the cellulose falls onto the wall furnace because the attic shield didn't work.

DSCN5560.jpg
 
Bama dav welcome to the BCF,

The basics; the code provides for prescriptive materials; Special Approval Section pertains to foam plastic coatings that are manufacturers proprietary products installed under specific conditions. Also see general requirements for spray polyurethane foam in Chapter 11. The protection from ignition and combustion are constantly evolving owing to new criteria and research and development.

Spray Foam dot Org and Mason Knowles are a good resource of technical and study information.

ICE you are so lucky! ;)

Francis
 
It's important to remember why there is an ignition barrier required in order to determine if you should be enforcing it in certain cases. The reason it is required is not because of the spread of fire, but the production of gases while it burns. All materials can spontaneously ignite once a certain temperature is reached, so after a building is burning for long enough for the temperature to reach the flash over point the released gas will spread the fire throughout the entire building. Remember, the protection is not for the building's inhabitants, but for fire responders.

We see spray foam used a lot in the joist header areas. It's typically a fight with contractor who don't want to finish a basement to get gyprock to cover it.
 
Is this the section you are talking about?.....if it is separated by 1/2" drywall mechanically fastened...you are good...I don't know how you do that in a crawlspace, inaccessible attic space, no prob, accessible attic gets a little grayer....

On a related note.....if you guys are seeing sprayed floors, do they drywall over or under the subfloor?????

R314.1.2 Thermal barrier.

Foam plastic, except where otherwise noted, shall be separated from the interior of a building by minimum ½-inch (12.7 mm) gypsum board or an approved finish material equivalent to a thermal barrier to limit the average temperature rise of the unexposed surface to no more than 250°F (121°C) after 15 minutes of fire exposure to the ASTM E 119 standard time temperature curve. The gypsum board shall be installed using a mechanical fastening system in accordance with Section R702.3.5. Reliance on adhesives to ensure that the gypsum board will remain in place when exposed to fire shall be prohibited.
 
When I was a kid living in Illinois I witnessed the application of spray foam insulation. The various components were mixed as it was sprayed. If the ratio of chemicals was off even a little bit, the stuff caught on fire. They had burning piles of foam and it took them a while to get it right.
 
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Steve,it's the words or an approved thermal barrier is where it gets fuzzy. It opens the door for the spray applied thermal barriers.Just not sure they meet the intent of the code.
 
Bama dav said:
Steve,it's the words or an approved thermal barrier is where it gets fuzzy. It opens the door for the spray applied thermal barriers.Just not sure they meet the intent of the code.
Click to expand...
Have them submit documentation on the barrier used. There are some spray applied systems that do comply with this section, but you need the documentation to ensure it was applied correctly and that is complies with the temperature rise requirement.
 
Floydman,the icc-es report is that the codes opinion or is it or should we have a 3rd party independent test? Will it stand in a court of law.
 
howdy, been dealing with this one alot lately here. "look, it doesn't really burn" yeah, well, see that thick black toxic smoke..... some people just don't understand. anyway, let me not digress to far herwe. the icc -es report is the place to get the info you need. i ask the contractor to supply all documentation. ( i usually find it before they ghet it to me, but thats another story)it will be specific to the type of insulation being sprayed. get a certificate on your installer, as well. . get that report, read up on the stuff, it'll say something like, " this product will comply with the code if a mixture of DCM-15 ( or some other letter /number combo) is sprayed over the enitre application at least 20 mils thick. ( some of this info i yanked from the icc-es report for a local job) for wording purposes only. goodluck partner
 
steveray said:
On a related note.....if you guys are seeing sprayed floors, do they drywall over or under the subfloor?????
Click to expand...
• nominal ¾ ” (19/32”) plywood [iBC Table 721.6.2(1)]

• Not prescriptive but generally accepted for floors

New in 2012; R316.4 NFPA 275

Alternative assemblies tested under AC377 Appendix X are not appropriate alternative assemblies for meeting thermal barrier requirements

AC377 Appendix X is used to qualify Ignition Barriers



Download size 4.87 MB: Spray Foam Presentation SE MASS BOA

Francis
 
Francis Vineyard said:
• nominal ¾ ” (19/32”) plywood [iBC Table 721.6.2(1)]• Not prescriptive but generally accepted for floors

New in 2012; R316.4 NFPA 275

Alternative assemblies tested under AC377 Appendix X are not appropriate alternative assemblies for meeting thermal barrier requirements

AC377 Appendix X is used to qualify Ignition Barriers



Download size 4.87 MB: Spray Foam Presentation SE MASS BOA

Francis
Click to expand...
"Seperated from the interior" would include seperation from a basement space, finished or not, and an attic space, finished or not.
 
Guys, I'm thankful for the help but the one I'm having a problem with is the one you

spray on like paint. Suppose to be put on at a rate of 20 mills thick.How in the world I'm I suppose

to verify the thickness? And it Does have an icc-es report .
 
Make sure everthing in the ES report is followed to the letter (That you can verify)...I guess you could request to see the empty material cans to verify coverage per square ft???? Or a letter from the installer, you have some lattitude here, discuss with the contractor and see what might work for both of you......Do you measure the 6mil plastic under the slab?
 
you can guesstimate the number of containers the job will need and either ask to see the empties, or ask for a sales receipt to verify.
 
Steve,I can pick up the poly and I know what 6mill feels like.As for as a letter from the installer,sorta like asking the fox to guard the hen house.Would you take a letter from the framer on the framing inspection.Just saying.
 
Guys,If you have been strugling with foam insulation and the code requirements check out the download that frances put up.It clearly spells out the differance between themal and ignition barriers.In my 22 years as a building inspector I have struggled with this one more than any I can remember.I hope the codes will get more clear on this product in the future.
 
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