DC 333 is a water based intumescent coating used to increase fire resistance ratings of construction materials like OSB/Plywood, gypsum and lumber. DC 333 is also effective at reducing flame spread ratings of materials not required to meet resistance ratings. Applied as a primer to interior surfaces, DC 333 can be top-coated with desired finish latex paint to match décor. NFPA 703, Standard for Fire Retardant – Treated Wood and Fire-Retardant Coatings for Building Materials, defines FRTW as “a wood product impregnated with chemicals by a pressure process or other means during manufacture, which is tested in accordance with ASTM E 84, Stan- dard Test Method of Surface Burning Characteristics of Building Materials, NFPA 255, Standard Method of Test of Surface Burning Characteristics of Building Materials or UL 723, Standard for Test for Surface Burning Char- acteristics of Building Materials; has a listed flame spread index of 25 or less; and shows no evidence of significant progressive combustion when the test is continued for an additional 20-minute period; nor does the flame front progress more than 10.5 feet (3200 mm) beyond the centerline of the burners at any time during the test.”


  • Finish: Flat
  • Packaging: 5 Gallon Pails
  • Color: Off White
  • V.O.C.: 56 g/L