Repairing Stone Window Sills Online

If you encounter lead paint (common on old sills), if the stone is part of a designated historic structure, or if the sill supports a lintel or significant weight above, hire a conservation mason. They have access to specialized stone-matching aggregates and injection grouts that are not available to the public.

Once the repair has fully cured (typically 7–28 days depending on the product): repairing stone window sills