One box of A+ treats 250 square feet. A+ mixes with any water-based paint to make each room resistant to Fire, Mold, Mildew, Fungus, and Algae. Hotels and Apartment buildings should use A+ to treat hallways and stairwells to make them resistant to fire in order to provide an increase in evacuation time. A+ increases evacuation time during a fire from 5 minutes to 20 minutes!! A+ is also a roof, wall, and floor sealant, preventing leaks and moisture. A+ is also resistant to Corrosion when applied to ANY metal. A+ has zero VOCs (Volatile Organic Compounds) and forms a barrier against Lead paint. According to tests conducted by ASTM International, A+ improves the integrity of the building from cracks, fissures, and possible building collapse. A+, when mixed with any grade cement increases the strength by 350%, a regular bag of cement with a psi of 1800 was increased to 6300 psi when A+ was added.