Stone veneer used on fireplaces consists of thin pieces of natural stone that have been split, sawed and tumbled to smooth out the rough edges. Without any kind of treatment, the stones remain dull in appearance. Enhance the stones by applying a sealant on them that makes them look wet and shiny, as if they were just plucked from the riverbed. Sealant also protects stone veneer from water damage and stains.
Masonry sealant is an acrylic/polyurethane liquid that, when dry, prevents moisture from entering the stone, yet breathes enough to allow existing moisture to escape. Sealants can come in several finishes, including clear, matte, semi-gloss and high gloss, among others. The type of sealant you use affects how the stones look. Sealants can also be tinted to enhance a certain color in the stone veneer. They are designed to repel moisture, but many are not waterproof. Generally, the higher the gloss, the more waterproof the sealant.
High-gloss sealant creates an ultrahard shell over masonry, including stone, tile, brick and concrete. Unlike the clear sealant alternatives, a high-gloss type creates a coat that is quite visible. High-gloss sealants are generally waterproof as well. Sealants that create film over the stones last longer than sealants that are clear, thereby extending the life of the stone fireplace. Aesthetically, a high-gloss sealant on a stone fireplace gives it a "wet" look, which is prized by many homeowners.
How It Works
When applied to stone, sealant prevents substances like oil and dirt from becoming embedded in the tiny pores all along the surface. The sealant fills the pores, while still letting moisture exit the stone. The molecular structure of the sealant creates a highly reflective surface, which enhances the stone's natural textures and patterns.
Clean the stone fireplace first, eliminating any oil, dirt or loose pieces of mortar. Apply liquid sealant in a thin layer with a roller or brush on clean, dry stones. Smooth out any drips or pubbles on the stone veneer. Allow the first coat to dry completely, then apply a thin second coat. Let the fireplace dry completely, about 24 hours, before allowing any hands on or near the stones.