Will expanding foam cure under water?
Mia Walsh
Updated on May 05, 2026
In respect to this, can spray foam be used underwater?
This version of Great Stuff expanding foam also offers water resistance. It is not meant to be in constant direct contact with water but is suitable for outside locations where exposure to water is likely.
Likewise, does Spray Foam keep water out? Closed cell spray foam can keep that water out, but that's not a fix because it isn't going to magically disappear or dissipate. The thing is, if you don't address the problems that lead to the leaks and you add foam, the water will start pooling in other areas as well and now the foam is hiding it.
In this way, does expanding foam stop water?
Using expanding polyurethane foam is one of the best ways to stop water leaks because the foam will expand into the cracks and help prevent future leaks. Expanding foam bonds to any type of surface and will quickly and effectively solve your water leak problems.
Will spray foam insulation stop water?
How they differ is that closed-cell foam is waterproof and will not let water move through it. Open-cell foam will allow water to move through it and dry. Insulation should not stop water. Roof, wall, and crawlspace assemblies are designed to keep water out.
Related Question Answers
What happens if spray foam gets wet?
Open cell spray foam insulation will still dry completely after getting wet. In addition, because spray foam is not a “food” for mold, there is little danger of mold becoming a problem even if it gets wet. Closed cell foams also do not absorb water, which is very beneficial in flooding zones.Where should you not use expanding foam?
When NOT to Use Spray Foam Insulation- For areas that are too close to electrical boxes:
- For areas too close to ceiling light boxes: You should not use spray foam to insulate areas around recessed ceiling canister lights.
- Open-cell spray foam on your roof:
- For closed-cavity spaces:
- If you have a history of skin, respiratory, or asthma problems: