Spray foam is applied wet and expands into thick foam that fills wall cavities, crevices and gaps, providing superior air sealing. Spray foam is extremely energy-efficient and can help make your home more comfortable year round, reduce noice levels, improve HVAC system performance, and protect against air and moisture infiltration. Spray foam can be used nearly anywhere (attics, walls, etc.). Thermashield offers a complete line of Johns Manville spray foam options.