How to Recaulk a Bathtub
Difficulty: Easy • Time: 45 min active, 1440 min total • Estimated cost: $8-15 • Safety: DIY-friendly
Overview
Caulk is the waterproof seal between your bathtub and the wall. Over time it cracks, peels, turns black with mold, or separates from the surfaces. When this happens, water can seep behind the wall, causing hidden damage that's expensive to fix.
Recaulking is cheap, straightforward, and prevents thousands of dollars in water damage. The key to a professional-looking result is 90% prep work — removing all the old caulk and cleaning the surfaces thoroughly before applying new caulk.
The active work takes about 45 minutes, but you'll need to let the new caulk cure for 24 hours before using the shower.
Tools Needed
- Caulk gun
- Utility knife
- Putty knife or 5-in-1 tool
- Rubbing alcohol
- Paper towels
- Painter's tape (optional but recommended)
- Spray bottle
Materials Needed
- Kitchen & bath silicone caulk (white or clear) — $5-8
- Caulk remover gel (optional) — $5-8
- Caulk gun — $5-10
Step-by-Step Instructions
- Remove all old caulk: This is the most important step. Use a utility knife to cut along both edges of the old caulk bead. Pull out as much as you can by hand. Use a putty knife to scrape remaining caulk from both the tub and wall surfaces. For stubborn caulk, apply caulk remover gel, wait 2-3 hours, then scrape. Every bit of old caulk must be removed — new caulk won't adhere to old caulk.
- Clean and dry the surfaces: Wipe all surfaces with rubbing alcohol to remove soap scum, oils, and residue. Let it dry completely — moisture prevents caulk from adhering. This is where most people fail. If the surface is even slightly damp or has soap residue, the new caulk will peel within months. Wait at least 30 minutes after cleaning.
- Apply painter's tape guides (recommended): Apply painter's tape along the tub edge and wall, leaving a 1/4 inch gap where the caulk will go. This creates perfectly straight lines and makes cleanup much easier. Press the tape firmly so caulk doesn't bleed underneath. This step is optional but makes the difference between an amateur and professional result.
- Apply the caulk bead: Cut the caulk tube tip at a 45-degree angle, making a small opening (1/4 inch or less — you can always cut more). Load the tube in the caulk gun. Starting at one end, apply steady pressure while moving at a consistent speed along the joint. One continuous bead is better than stopping and starting. Don't go too fast (thin bead) or too slow (thick bead).
- Smooth the bead and remove tape: Dip your finger in a cup of water (or spray water from a spray bottle onto the bead). Run your wet finger along the entire caulk bead in one smooth motion to create a concave, professional finish. Wipe excess caulk from your finger with a paper towel. Remove the painter's tape immediately while the caulk is still wet — pulling at a 45-degree angle away from the bead. Let cure 24 hours before using the shower.
When to Call a Professional
Call a professional if you see mold or rot behind the old caulk (indicates water damage that needs repair before recaulking), if tiles are loose or cracked (water may already be behind the wall), or if the gap between tub and wall is wider than 1/2 inch (may need backer rod or a different repair approach).