Q&A Forums
wood as a thermal barrier??? Post New Topic | Post Reply
| Author | Comments |
|---|---|
|
Craig Maturi
Posted: May 17, 2007 08:15 AM
|
wood as a thermal barrier???
i sprayed a house with open cell and the owner was gonna just put 3/4" toung and groove right on top of the poly on the walls. inspector came in and said he had to put 1/2" sheetrock on first!!! does he have to?
|
|
philip mullins
Posted: May 17, 2007 03:23 PM
|
1 |
|
Gerry Wagoner
Posted: May 17, 2007 06:13 PM
|
I didn't in our master bedroom. Norway pine on the cathedral ceilings. Weren't inspected tho... oG |
|
Thomas Kasper
Posted: May 17, 2007 10:51 PM
|
I think that is a state code not national code and I also think we can use wood as a thermal barrier in wisconsin. I've only been told it's ok by my salesman that it just passed last year. |
|
mason
Posted: May 18, 2007 12:47 PM
|
In the 70s the Society of the Plastics Industry in cooperation with the foam plastics industry conducted testing of various products as thermal barriers over foam. 3/4" tongue and groove wood decking was one of the materials tested that passed the thermal barrier tests. However, it is not specifically listed in the national codes and I am not aware of recent tests on the product. This is one of those cases where the building code official may or may not approve it based on his understanding of whether it complies with the the code. I'll make a few calls to ICC Evaluation Services to get an up to date ruling. |
|
Posted: May 18, 2007 03:43 PM
|
so are we being covered with a thermal barrier due to flame spread or smoke developement?? if flame spread,,,how comes a pine or fir frameing timber can be "left exposed" when it is a class III flame spread,,,as is most of the wood products....i mean we have a flame spread of 25 or less,,,they have a flame spread of 75 or greater,,,most alot greater... why is it that polyurethane decorative trim moldings can be used,,,anyone put a flame to a piece of this stuff,,,unrated foam me thinks,,,how is it that unrated foam is in the couch, chairs and beds,,,buts thats ok... we are unable to spray box sills and band joists in the unfinished basement...a high leaking loss area... IS REDUCEING OUR DEPENDANCE ON FOREIGN OIL JUST LIP SERVICE... IS BUILDING GREEN JUST A CLICHE... |
|
mason
Posted: May 18, 2007 03:54 PM
|
The surface of SPF and other polyurethane foam can flash at temperatures around 600-800 degrees F. (easily achieved in a house fire.) The speed at which the flames and smoke travel make this a dangerous fire situation for anyone inside the building. A thermal barrier stops this from happening. ASTM E119 (corner room fire test) is used to determine if a material can be used as a thermal barrier. If it prevents the surface of the foam plastic from getting to 250 degrees in 15 minutes of fire exposure, it passes. So, wood can be a thermal barrier in this test. For more specific information check out SPFA's Thermal Barrier Technical Document AY 126 at Sprayfoam.org By the way, SPF (closed cell class 1)is specifically allowed in sill plate applications without a thermal or ignition barrier, based on corner wall fire test performed a few years ago at Southwest Research Labs. |
|
Posted: May 19, 2007 01:25 AM
|
can you reference a document for the sill plate applications for my freindly neighborhood inspector...seems they think foam is explosive... |
|
mason
Posted: May 19, 2007 09:42 AM
|
Foamdude. It is actually in the ICC codes both in the International Residential Code and the International Building Code. It is in the plastics section under exceptions to thermal barrier. |
|
Gerry Wagoner
Posted: May 23, 2007 10:03 AM
|
And radioactive, Foamdude :). |
|
Gary Galloway
Posted: May 30, 2007 01:37 AM
|
Does this mean there is a foam that could be used to insulate the underside of a commercial building roof without having to cover it with 5/8 inch firerock ??? I am refering to closed cell class I foam mentioned in this tread. |
|
mason
Posted: May 31, 2007 04:05 PM
|
GDgalloway, In the inhabited areas of all buildings foam plastic must be covered with a thermal barrier as defined by the codes or as tested in the room corner fire test. I am not aware of a foam plastic that has passed these tests without some type of covering. Now in attics and crawls spaces the test has a lower pass/fail criteria and a couple of products have received approvals on horizontal surfaces without coverings. There is some controversy on the test procedures and the pass/fail criteria. The SPF industry is currently reviewing the attic and crawl space fire test in order to make recommendations to the ICC Evaluation Services. |
