Is spray foam on basement walls safe behind drywall in flood‑prone areas?

Trade Talk
1

Is spray foam on basement walls safe behind drywall in flood‑prone areas?

3 Likes
2

closed cell spray foam directly on concrete or block is one of the best insulation methods.

Foam works better than vapour barrier in most cases, it retains zero water, and does not feed mould.

1 Like
3

Yep, closed-cell spray foam can work behind drywall in basements that sometimes flood. It doesn’t absorb water or grow mold if it gets wet.

Even so, if your basement floods, the drywall and wood can still be ruined and need replacing. If water sits behind the foam, it can cause rot.

For safety, use water-resistant drywall and ensure your basement drains well. Spray foam helps, but it’s not a total fix for flood damage.

1 Like
4

Closed-cell spray foam can be safe behind drywall in flood prone basements. It doesn’t absorb water and acts as a vapor barrier, making it better than open-cell foam (which soaks up moisture).

That said, if water gets trapped behind the foam, it can hide mold or damage. Best practice? Use it directly on concrete, pair with mold-resistant drywall or non-organic wall materials. In high risk areas, consider rigid foam boards with removable panels instead.

1 Like
5

Spray foam insulation on basement walls can be safe behind drywall in flood-prone areas if installed correctly

To ensure safety and effectiveness

  1. Professional Installation is required

  2. Choose the right type

  3. Address moisture issues