Coming up on my inspection and I am unsure what to use to fire-block/draft stop parts of my basement.

The framing around the perimeter sits between 4" to 6" away from the poured concrete. I'm using this spray foam to fill smaller gaps and holes (It says it's fire rated on that link) enter image description here

I was thinking of using either faced or unfaced insulation such as this product for the vertical draft stopping every 8 to 10'. Staple it to the wood and then use tape to fasten the other side to the radient barrier.

Would that be sufficient or do I need to consider a different product?

  • 2
    Why are your 2x walls so far away from the concrete in the first place? Seems like a lot of wasted floor space. Or are you using that space for Scooby Doo style secret passages?
    – FreeMan
    Nov 17, 2021 at 16:49
  • The framing was partially completed when we moved in and felt like it wasn't worth it to redo it. The wall pictured has the waste sewage lines running on it. the other walls are more like 2-3" away from the concrete.
    – EMAW2008
    Nov 17, 2021 at 16:53

1 Answer 1


Fireblocking is required at 10’ on center both vertically and horizontally. (See R602.8)

Acceptable materials are 2x material or 1x material with joints backed up, or one layer of 23/32 structural panels (plywood), 3/4” particleboard, 1/2” gypsum board, 1/4” cement based mill board, but must be secured. Batts and blankets of mineral wool or glass fiber installed in a secure manner. (See R602.8.1)

Loose fill insulation is not approved.

  • So a material says that's it's fire-rated, that's good enough?
    – EMAW2008
    Nov 18, 2021 at 20:57
  • 1
    It has nothing to do with being “fire rated”. This is about “fireblocking”. So it has to do with stopping (or containing) air flow and limiting it to 10’ vertically and horizontally.
    – Lee Sam
    Nov 18, 2021 at 23:19

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