WT-103 5 Gal. Clear Matte Latex Interior Intumescent Fireproofing Flame Retardan por | 24 Jul 2026WT-103 5 Gal. When properly applied, WT-103 complies with ASTM E84, Class B or Class 2, NFPA 255, UL No. 723, UBC 42.1 and more. Suitable for application on raw wood. Coverage is 200 sq. ft./gallon in 2 coats.