Stains and coatings are used for aesthetic reasons, and also to improve the resistance to certain exposures (e.g., reduce weathering, improve resistance to mold or stain fungi). Film-forming paints and penetrating stains haven't been shown to provide long-term improved performance from fire exposures. None of these products has demonstrated long-term fire-resistance performance in an exterior environment. Until these products can show adequate performance after a defined weathering procedure, they should not be relied on to improve the fire performance of exterior-use building materials.
