Closed-cell foam is a foam structure made of sealed, gas-filled cells with no connecting pathways between them, which makes the cured material rigid, load-bearing, and resistant to water.
In depth
When polyurethane reacts under a slab it forms a closed-cell structure: each tiny cell is sealed off from its neighbors. Because water cannot pass from cell to cell, the foam blocks moisture infiltration and stays dimensionally stable even when saturated. That same sealed structure gives the foam its strength, letting a lightweight material support heavy concrete.
Closed-cell structure is the key reason polyurethane outperforms aggregate slurry: it will not absorb water, wash out, or lose strength when wet.
How Acme applies it. Acme’s injection process forms a moisture-resistant, structurally stable closed-cell foam on every shot, verified by pressure gauges at the injector that confirm the A- and B-sides are mixing in the right ratio.
Related terms: Polyurethane Foam, Hydrophobic Foam, High-Density Foam, Compressive Strength
Frequently asked questions
Why does closed-cell structure matter for concrete lifting?
Sealed cells block water and resist compression, so the foam supports load and stays stable underground for decades rather than absorbing moisture and degrading.
Does closed-cell foam absorb water?
No. Because each cell is sealed and gas-filled, water cannot travel through the material, which is why cured polyurethane is effectively waterproof.