Open Cell Foam in Roof Rafters

[Francis Vineyard]

Jobsaver these products are in constant flux, I check the specs each time. I think one of them was something like Flame Seal, need to keep checking their certification and limitations of what brand and density of foam they approve.

TimNY I believe none of these SPF can be used unless they meet Class B as noted in section 3.2 and IRC314.3, so yes a thermal barrier is needed if a floor, platform or shelving is provided in excess of what the code prescribes for servicing of appliances.

One of the most common mistakes made here is when an attic is finished with the HVAC behind the knee wall and SFP needs a thermal barrier including the interconnected space, since this is now on the same level as a floor because an attic is defined as the space above the ceiling of the top floor.

There may be another intumescent coating available, waiting for test information from manufacturer. Saves time contacting the manufacturer for specific information instead of searching elsewhere.

 

[Francis Vineyard]

Section “FOAM PLASTIC” specifies “prescriptive” thermal (½ gypsum) and a list of ignition barriers. In lieu of these prescriptive barriers the material must comply with Section “Specific approval” to use the alternate spray applied thermal barriers (cementituous and fiber base) and ignition barriers (intumescent coatings).

Upon review of some of the revised ESR’s I notice that there are usually two intumescent coatings listed; they may specified to be applied vertical only, horizontal only or both and restricted to the thickness of foam plastic insulation.

Reference: http://www.sprayfoam.com/aeps/aeitem.cfm?aeid=1049