How to Recaulk a Bathtub or Shower
Short answer: Remove all the old caulk, clean off residue and mildew, let the joint dry completely, then tape both sides, run a bead of kitchen and bath caulk, smooth it, pull the tape while wet, and let it cure for about 24 hours before using the tub.
- Difficulty
- Easy
- Time
- 1 to 2 hours, plus 24 hours to cure
- Updated
- November 9, 2026
What is causing it?
Caulk at the tub-to-wall joint seals out water that would otherwise get behind the tile and rot the wall. It fails from age, movement, mildew and poor adhesion. New caulk will not stick to old caulk, especially silicone, so removal is most of the job.
Tools and materials
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Tools
- Caulk removal tool or plastic razor scraperUse plastic on acrylic or fiberglass tubsCheck price on Amazon
- Utility knifeCheck price on Amazon
- Dripless caulk gunCheck price on Amazon
- Painter's tapeCheck price on Amazon
Materials
- 100% silicone kitchen and bath caulk with mildew resistanceCheck price on Amazon
- Silicone caulk removerCheck price on Amazon
- Mineral spirits or rubbing alcoholCheck the caulk label for the recommended cleanerCheck price on Amazon
- Mildew cleanerCheck price on Amazon
How do you recaulk a bathtub? Step by step
Cut out the old caulk
Slice along both edges of the bead with a utility knife, then pull and scrape it out. On plastic or acrylic tubs, use a plastic blade so you do not scratch the surface.
Remove the residue
Apply caulk remover if needed and scrape off every trace. Family Handyman stresses extra effort with old silicone, because new caulk will not bond to it.
Kill mildew and clean
Treat mildew in the joint with a mildew cleaner, rinse, then wipe with the solvent the caulk label recommends.
Dry completely
Let the joint dry thoroughly; overnight is safest. Fill the tub with water before caulking so it is at its lowest point and the caulk does not stretch later.
Tape and caulk
Put tape on the tub and wall about 1/8 inch from the joint. Cut the tube nozzle small, and run a steady, continuous bead into the joint.
Smooth and pull the tape
Smooth the bead with a wet fingertip or a caulk tool in one pass. Pull the tape right away at a 45 degree angle while the caulk is wet.
Let it cure
Keep water off it for the time on the label, commonly about 24 hours, then drain the tub.
Safety notes
- Ventilate the bathroom when using caulk remover, mildew cleaner and solvents.
- Never mix bleach-based cleaners with ammonia or other cleaners.
- Wear gloves and eye protection when scraping.
When should you call a pro?
- Tiles are loose, or the wall behind the tile feels soft when you press it.
- Water stains appear on the ceiling below the bathroom.
- The tub moves or flexes when you stand in it.
Frequently asked questions
Silicone or acrylic caulk for a tub?
100% silicone lasts longest in wet areas and stays flexible. Acrylic latex kitchen and bath caulk is easier to tool and clean up and can be painted. Both should be labeled for kitchen and bath use.
Why do I fill the tub with water before caulking?
The weight makes the tub settle slightly. Caulking it in that position means the bead is not stretched and torn the first time someone takes a bath.
How often should I recaulk?
When the caulk cracks, peels, pulls away, or stays moldy after cleaning.
Sources
Steps are based on these manufacturer and safety references. Your product's own manual comes first.