Waterproofing an Old Limestone Foundation with Closed Cell Spray Polyurethane Foam

Waterproofing an old limestone foundation from the exterior with “Closed Cell” spray polyurethane foam provides a water tight seal from the outside.

Closed cell spray polyurethane foam provides more than 3x the waterproofing and 4x the compressive strength of Extruded Polystyrene (EPS) which are the pink boards sold at Home Depot, Menards, Lowes, etc. These pink boards allow water to permiate through them reducing their thermal efficiency and letting water through. Closed Cell when applied to a crawlspace or basement wall is sprayed seamless so no water is able to penetrate.

So why is this important? Like clothing when wet, it does not insulate nearly as well. In applications below grade, there is nothing but moisture and ground water saturated in the soil. Closed cell spray polyurethane is the only logical answer for a seamless waterproof insulation.