3 ms·

Won't the foam deteriorate over time, possibly faster than the concrete ?

• londons_explore 6y ago
  Yes, but it doesn't matter. The foam really acts as a spacer to convert a single block of concrete into two blocks separated by a few millimeters. As soon as the concrete is set into place, the foam has done its job and can degrade all it likes.
  • m4rtink 6y ago
    Interesting! But what holds these blocks at the separation once the foam is no longer load bearing ? Some external bracing ?
    • londons_explore 6y ago
      Typically the foam is only in the middle of the concrete slab, so there are still a few inches of attachment all around all the edges with contact. There is rebar in those edges too.
      • m4rtink 6y ago
        Interesting, do that's how it works - thanks for the explanation! :)