How to Recaulk a Bathtub

Bathtub caulk fails. It cracks, yellows, develops mold, or simply stops adhering to the tile. The good news: recaulking is one of the most forgiving repairs in a bathroom. You don't need special skills, and the materials cost under twenty dollars. What matters is patience with removal and cleanliness before you apply fresh caulk. A well-done caulk joint lasts five to seven years and keeps water from migrating behind your walls where it becomes expensive problem real fast. The job splits into three phases: getting the old stuff out, getting the joint clean and dry, and running a new bead. Most of the time goes to removal, and that's where care pays off. Rush this step and you'll spend the rest of the project picking bits of old caulk out of your new application. Take your time here, and the rest becomes straightforward.

1. Score and loosen the old caulk. Use a utility knife or caulk removal tool to cut along both sides of the existing caulk bead, pressing firmly into the joint but not so hard you gouge the tub or tile. Make several passes if needed. Once scored, use the flat end of a caulk removal tool or an old putty knife to pry up the edge and begin peeling the caulk away in long strips. Work methodically—this isn't a sprint.
2. Remove stubborn caulk residue. Once the bulk is gone, you'll have dried bits clinging to the tile and tub edge. Use a plastic scraper or old credit card to gently lift these without scratching surfaces. For really stubborn spots, apply a commercial caulk remover (follow the product timing), or use rubbing alcohol on a cloth to soften any remaining adhesive. Be patient—residue left behind will show through new caulk or create an uneven surface.
3. Clean and dry the joint. Wipe the entire joint line with a damp cloth, then follow with a dry cloth to remove dust, soap residue, and any lingering bits of old caulk. If mold or mildew is present, wipe with a 50/50 bleach solution, let sit for 10 minutes, then rinse thoroughly and dry. The joint must be completely dry before caulk goes in—moisture is the enemy of adhesion. Wait at least an hour, or use a hair dryer on cool setting to speed it up.
4. Tape along the edges for a clean line. Apply painter's tape on both sides of the joint, positioning it about 1/8 inch away from the gap itself. Press it down firmly so caulk can't seep underneath. The tape serves as a guide and makes cleanup infinitely easier. Remove it immediately after smoothing—waiting until caulk fully cures can cause adhesion loss when you peel it off.
5. Load and apply the caulk. Insert a silicone caulk cartridge into a caulk gun, cut the tip at a 45-degree angle with a utility knife, and pierce the seal inside the tube with the gun's punch. Hold the gun at a 45-degree angle to the joint and apply steady, moderate pressure as you move along the tub edge. Move at a consistent speed—fast application leaves gaps, slow application creates uneven beads. Fill the joint fully but don't overstuff it; you want enough to smooth but not so much that it squeezes out excessively.
6. Smooth the caulk bead. Immediately after applying caulk (within 5 minutes), wet your index finger slightly with water or a caulk-smoothing solution, then run it along the entire bead with steady, moderate pressure. This pushes the caulk into the joint and creates a concave profile that looks professional and sheds water better. Work the full length without stopping. If you mess up a section, wipe it off, reapply, and smooth again.
7. Remove tape and clean up. Peel the painter's tape away while the caulk is still wet, using a slow, steady motion at a low angle—this helps prevent the caulk from stretching or tearing. Wipe any excess caulk from the tub or tile with a damp cloth immediately. Do a final inspection for gaps or high spots. Clean your caulk gun by removing the cartridge and wiping the tip before any caulk hardens.
8. Let it cure fully before water exposure. Keep the bathroom dry for 24 hours. Don't shower, run the tub, or splash water on the new caulk. Silicone caulk forms a skin in hours but takes a full day to cure throughout. Using the tub too soon will compromise the seal and potentially trap moisture in the joint, which defeats the whole purpose. Mark your calendar or set a phone reminder if you tend to forget.