Trojan Masonry Sealer penetrating sealer fills the voids and coats the interior particles of the matrix to waterproof and reduce vapor transmission in concrete and masonry. The product works on sidewalks, driveways, floors, pavers, and other surfaces, indoors or outdoors. In addition, the sealer is suitable for historic preservation projects, because it strengthens the substrate and creates a flat finish, rather than a sheen. Eco-Wares. 866-874-8070.