The one draw back that I have found. The coating protects the rigid foam insulation board or ICF from U.V. It can be troweled smooth, or brushed to make a super rough finish. The product is not warranted as suitable for any purpose or use other than the general purpose for which it is intended. If you add Boost, a wet mix is stronger. If you would like to send some scraps of this foam to us we will do some testing: Hurricane Harvey Relief Fund, One coat system for exterior or interior use, Bond directly to foam panels without wire reinforcement or fiberglass fabric, Fiber-reinforced for improved flexural strength and reduced shrinkage, Protects and damproofs ICS forms for below grade use. Rock hard finish for all of your outdoor (and indoor) foam … 50 lb (22.7 kg) bags - 64 per pallet, Data Sheet Rock hard coating for all your outdoor (and indoor) foam projects.