Thompson's One Coat Roof Seal can be applied by brush, roller or a soft broom. Brush out Thompson's One Coat Roof Seal to approximately 1mm deep. Thompson's One Coat Roof Seal is rainproof immediately and reaches full protection within 24 hours. If heavy or prolonged spells of rain are experienced within 24 hours of application, check surface and if necessary apply a second coat. Where major joint movement may occur, embed a reinforcing scrim bandage into the Thompson's One Coat Roof Seal coating to reinforce the area.