NFPA 285 vs. Air Barriers

[Paul Sweet]

Does anybody know of a "peel & stick" air barrier (like Henry Blueskin) that has actually been tested to NFPA 285? We are dealing with an OHJ who will not accept engineering evaluations from DrJ, Priest, etc., but only actual test reports and ICC-ESR.

I found some tests for spray foam insulation and sprayed air barriers on UL & Intertek websites, and ICC has an ESR for Tyvek. Everything else I have found that claims to pass NFPA 285 relies on DrJ or Priest evaluations.

 

[RLGA]

NFPA 285 is an assembly test and not a material test. If an air barrier has been tested per NFPA 285, then it was tested as a part of a complete wall assembly, which you would then have to replicate component by component.

If the air barrier is the only combustible material in the wall assembly, then the 2015 IBC and later edition have exceptions to the flame propagation requirement in Section 1403.5 that allow air barriers that also function as water-resistive barriers to be used provided the material has a flame spread and smoke-developed indexes of 25 and 450, respectively, total and peak heat release rates and as indicated in the exception, and a heat of combustion of less than 18 MJ/kg.

You may have to ask the manufacturer for the test data (if they have it) for the heat release rates and the heat of combustion. Most products will show the FDI and SDI per ASTM E 84/UL 723.

 

[Paul Sweet]

I'm still trying to get my head around this, and I've looked at so many DrJ & Priest reports and manufacturers' equivalency tables that my head is still spinning. From what (little) I understand most manufacturers are recommending using IBC 104.11 Alternative Materials, and I believe the DrJ & Priest reports also mention this. The Priest reports reference the ASTM C1394 calorimeter test instead of the old tunnel test, but they also say that their test data is confidential.

Some manufacturers cite IBC 1403.5 as the way their products meet NFPA 285. Unfortunately, this building also has polyiso insulation in the cavity.

 

[RLGA]

I'm still trying to get my head around this, and I've looked at so many DrJ & Priest reports and manufacturers' equivalency tables that my head is still spinning. From what (little) I understand most manufacturers are recommending using IBC 104.11 Alternative Materials, and I believe the DrJ & Priest reports also mention this. The Priest reports reference the ASTM C1394 calorimeter test instead of the old tunnel test, but they also say that their test data is confidential.

Some manufacturers cite IBC 1403.5 as the way their products meet NFPA 285. Unfortunately, this building also has polyiso insulation in the cavity.

Then it sounds like you'll need to either find a tested assembly or work a NFPA 285 test into the project budget.

 

[Paul Sweet]

I think we have finally resolved this. A manufacturer's rep meet with the AHJ and showed them how the products listed as substitutions were evaluated and found to be less combustible than the actual products utilized in the passing NFPA 285 assembly. In other words, the worst case scenario product was tested and the evaluation reports are based on ICC-ES ESR for the passing / approved NFPA 285 wall system.

The AHJ also agreed that since DrJ & Priest are ANSI accredited product certification bodies, they will accept their evaluation reports as verification of compliance with NFPA 285.

I hope I missed something, but when I looked through UL and Intertek NFPA 285 tests the only air barriers I only found were one liquid-applied air barrier, Tyvek, and multiple manufacturers of sprayed polyurethane foam.