A fast curing, one component elastomeric, solvent free, moisture cure waterproofing compound designed to provide a cold alternative to hot applied rubberized membrane systems or replace conventional hot mop felt ply and/or pre-formed sheeting systems. It is applied in a high build two ply system or single ply application which cures through reaction with airborne moisture to provide a heavy-duty “seamless” rubber-like, impervious membrane.