Best Caulk For Sill Plate

Look for a sealant labeled minimal expansion.

Best caulk for sill plate.

If you have a concrete block foundation also seal the openings on top with expanding foam. Over time it can crack and chip allowing water to seep or. In other words caulking is applied where moisture would otherwise penetrate and cause deterioration. Stuff a wad of fiberglass insulation into each opening to support the foam as it hardens see figure a in the horizontal callout.

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. Fasten the sill plate to the concrete slab following the recommendations of the local building code. Sill sealer is a pliable foam product that is available in varying widths up to 10 inches wide. Ordinary foam sill sealer works best as a capillary break but it doesn t always work so well as an air seal.

Caulking is a sealant that fills gaps cracks nail holes and similar imperfections on the surface. If you have a solid concrete foundation also run a bead of caulk where the sill plate meets the concrete. Some codes require that the sill plate be bolted to the slab while others recommend a metal. Flexible foam sealant designed for use on both wood and masonry is the best type of caulking for sealing the sill plate.

Use around the perimeter of windows to help seal the window to the header sill jack stud and jamb. 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.