DRYLOK Water-Base 5% Silicone Brick and Masonry Sealer is a clear, durable, water-repellent, specialty formulation for use on exterior, above-grade, vertical brick and masonry surfaces. With just one coat, it minimizes the deterioration of masonry and mortar, and helps control efflorescence (salt deposits) and surface staining. DRYLOK Water-Base 5% Silicone Brick and Masonry Sealer prevents moisture penetration and eliminates plaster cracking, paint blistering, and damp staining of interior finishes.