Regrout a Kitchen Backsplash

Cracked grout behind your kitchen sink tells a story — years of temperature swings, moisture cycling, and the daily splash zone taking its toll. The grout itself doesn't fail from age; it fails from movement, from tiles expanding and contracting against an inflexible bond that eventually fractures. Regrouting a backsplash fixes the visible cracks and stains, but more importantly, it reseals the barrier that keeps water from reaching the drywall behind your tiles. This is a weekend project that pays immediate dividends. Fresh grout transforms a tired backsplash and buys you another decade of protection. The work is methodical rather than difficult — careful removal, thorough cleaning, precise application. Most people rush the removal phase and pay for it with poor adhesion. Take your time with the grout saw, get every joint clean down to the tile edge, and the new grout will lock in solid.

1. Cut grout deep and clean. Run a grout saw down the center of each grout line, applying steady pressure and making multiple passes until you reach a depth of at least 1/8 inch. Work systematically across the backsplash in sections, not random lines. The grout should come out as dust and small chunks, not in one continuous strip — that means you're cutting deep enough.
2. Clear all dust and debris. Use a shop vacuum with a brush attachment to pull all grout dust from the joints. Follow with a damp sponge to wipe down the tile faces and remove any remaining film. Let everything dry completely for at least two hours before grouting.
3. Hydrate grout to perfect thickness. Pour water into a clean bucket first, then add grout powder while mixing with a margin trowel. Target a peanut butter consistency — thick enough to stay in the joints but spreadable without excessive force. Let the mixture slake for ten minutes, then remix without adding more water.
4. Pack grout deep into joints. Load grout onto a rubber float and press it into the joints at a 45-degree angle, working diagonally across the tiles. Make two passes over each section — first to fill, second to pack the grout firmly into the joints. Scrape off excess by holding the float at 90 degrees to the tile surface.
5. Wipe grout haze off tiles. Wait 15-20 minutes after grouting each section, then wipe the tiles with a damp sponge in circular motions. Rinse the sponge frequently and wring it nearly dry — too much water will pull grout out of the joints. Make multiple light passes rather than one aggressive scrub.
6. Profile joints for durability. Once the grout is firm but not fully hard — usually 30-60 minutes after application — run a damp sponge along each joint to create a smooth, slightly concave profile. This final pass evens out any low spots and gives the grout lines a finished appearance.
7. Keep water away for three days. Keep the backsplash dry for 72 hours. No splashing, no wiping with wet sponges, no steam from boiling pots directly hitting the fresh grout. The grout needs this time to cure fully and reach maximum strength. Cover adjacent counters with towels if needed to remind yourself.
8. Lock in water protection. After 72 hours, apply grout sealer with a small brush or foam applicator, working it into the grout lines without getting excessive sealer on the tile faces. Let it absorb for ten minutes, then wipe away any residue. Apply a second coat after four hours for maximum water resistance.