How to Caulk the Gap Between Backsplash and Countertop

The gap between your backsplash and countertop is a magnet for crumbs, grease, and water. It's not just a cosmetic problem—moisture working into that seam will damage both surfaces and eventually rot the wall behind the backsplash. The good news is that caulking it is straightforward work that costs almost nothing and looks professional when done right. A clean, properly sealed edge transforms a sloppy-looking kitchen into one that reads as finished and maintained.

1. Strip the Old Bead Clean. Use a caulk removal tool, old flathead screwdriver, or utility knife to cut away the existing caulk in one continuous strip. Work slowly and don't gouge the tile or countertop surface. A caulk softener (spray it on, wait 15 minutes) makes this easier if the old caulk is stubborn.
2. Get the Gap Dust-Free. Vacuum out all the loose caulk fragments and crumbs. Then wipe the gap with a damp cloth or paper towel, getting into the corner where tile meets counter. For stubborn silicone residue, use rubbing alcohol on a cloth and scrub the surfaces dry. Let the gap air-dry for at least 10 minutes.
3. Tape for Crisp Edges. Run painter's tape along both sides of the gap—one line on the backsplash, one on the countertop, about 1/8 inch away from the seam. This prevents caulk from smearing onto surfaces where it doesn't belong and gives you a crisp, professional edge. Press the tape down firmly with your fingernail.
4. Load the Gun Right. Insert a fresh tube of kitchen-grade silicone caulk into your caulk gun. Cut the tube tip at a 45-degree angle, making the opening roughly 1/8 inch wide—this size matches most kitchen gaps. Cut it smaller rather than larger; you can always squeeze out more. Pierce the internal foil seal with the long pin on the back of the gun.
5. Run One Smooth Bead. Hold the gun at a 45-degree angle so the tip sits in the gap. Squeeze with steady, even pressure while moving the gun along the seam in one continuous motion. Go slowly—speed causes gaps and uneven beads. The caulk should completely fill the gap and sit slightly proud (raised) above the surface. Work in sections if you're doing a long run; doing 3–4 feet at a time keeps the material workable.
6. Finger-Smooth the Seam. Dampen your index finger or a caulk finishing tool with water. Run it along the fresh caulk bead in one smooth stroke, pressing lightly to seat it into the gap and remove excess. This creates a smooth concave profile that looks finished. Wipe your tool or finger on a wet cloth between passes to avoid dragging caulk back out.
7. Cure Untouched for 24 Hours. If you used painter's tape, peel it away gently at a 45-degree angle while the caulk is still slightly tacky, about 30 minutes after application. Don't let it fully cure first or tape removal will tear the caulk edge. Let the caulk cure for the full 24 hours before running water or cleaning near it. Avoid touching the seam during this time.