That's good to know, I had thought the water/acrylic based were safe. The water proofing you put on should of not done much if you had the polyurethane on thick enuff. They both are sealers and should protect the wood from allowing moisture/water into the wood. Polyurethanes just create that hard clear coating where as the sealer you applied soaks into the wood and acts like the stuff applied to pressure treat wood on desks etc... I knew to avoid the polyurethanes they will release fumes for several months even and can impact the pets health.