Is Liquid Rubber Foundation Sealant safe for drinking water? Currently we do not have a certification allowing this use. Related articles How do I cover gaps and cracks? Can this product be used to waterproof shower walls and base? Can it be tiled over? What if I don't want black as my final color? Can I build my final membrane all at once? Will sun have an effect on the Liquid Rubber Foundation Sealant? Comments 0 comments Please sign in to leave a comment.