Combustible foam on exterior wall/roof near property line

[Ryan Schultz]

In the scenario below, possible to use EPS or Polyiso on the roof? I assume it is if it meets 2603.6 Roofing

Possible to use EIFS on that 1st floor wall? I assume it is because of 2603.4 Thermal Barrier. That is, the concrete acts as the the 'thermal barrier'.

 

[RLGA]

EIFS can be used on any construction, since it is required to be tested per NFPA 285 as part of its compliance with ASTM E2568 per IBC Section 1408.2. The concrete is sufficient as a thermal barrier for the wall to comply with 2603.4. It will have to be part of a 2-hour tested assembly, though, for exposure on both sides.

Foam insulation can be used on a roof as long as it is covered by an approved roof covering and complies with either NFPA 276 or UL 1256 when tested as an assembly per IBC Section1508.1 and Section 2603.4.1.5, Item 2.

The issue I have is how can you have a Group S-1 in Type IB construction below a Group R-2 in Type VB construction with only a 2-hour horizontal assembly?

 

[Ryan Schultz]

Thank you kindly for the explanation.

I'm using 510.4 Parking Beneath Group R to realize a 2hr between the VB and the 1B

 

[RLGA]

Then it should be a Group S-2 and not S-1.

 

[Ryan Schultz]

Typo, thank you.