Best Caulk For Sill Plate

Flexible foam sealant designed for use on both wood and masonry is the best type of caulking for sealing the sill plate.

Best caulk for sill plate.

Fasten the sill plate to the concrete slab following the recommendations of the local building code. If you have a solid concrete foundation also run a bead of caulk where the sill plate meets the concrete. If you have a concrete block foundation also seal the openings on top with expanding foam. Ordinary foam sill sealer works best as a capillary break but it doesn t always work so well as an air seal.

Over time it can crack and chip allowing water to seep or. Stuff a wad of fiberglass insulation into each opening to support the foam as it hardens see figure a in the horizontal callout. In other words caulking is applied where moisture would otherwise penetrate and cause deterioration. Look for a sealant labeled minimal expansion.

One option for improving the air seal if you use conventional sill seal is to seal from the inside with high quality polyurethane or a siliconized acrylic caulk formulated for adhering to concrete. Best uses for silicone sealants silicone is very flexible and acts as a water and moisture repellant making silicone sealants the best caulk for windows and bathrooms. Latex caulking can harden and crack and pure silicone caulking can pull away from the masonry if it becomes wet. A filler similar to caulk is generally used to seal these gaps between the sill plate and foundation when the home is constructed.

The best way to air seal the sill plate is to place a sill sealer also called a sill gasket on the concrete before laying down the sill plate. Caulking is a sealant that fills gaps cracks nail holes and similar imperfections on the surface. Use around the perimeter of windows to help seal the window to the header sill jack stud and jamb.