How to Seal Wall Joints Around a Tub or Shower

You're much better off maintaining the caulk joints around a tub
or shower base than cleaning up the mess that results when water
penetrates that protective barrier.

Difficulty: Moderate

Instructions

Things You'll Need:

• Caulk-removing And Softening Chemical
• Painter's Masking Tape
• Hair Dryer Or Heat Gun
• Cutting Board
• Utility Knife
• Utility Knife
• Caulk-smoothing Tool
• Flathead Screwdriver
• Plastic Putty Knife Or Single-edge Razor
• Tub-and-tile Caulk
• Vacuum with pointed attachment, toothbrush or small brush

1. In areas where the caulk is still bonded, use a plastic putty knife or (with porcelain tubs only) a single-edge razor to break the bonds between the caulk and the fixture and between the caulk and wall. Hold the putty knife at an angle, with the pointed corner at the edge of the caulk; hold the razor blade at a low angle, with its edge on the tub or wall surface, and push it into the caulk.

2. Use a flathead screwdriver to scrape out loose caulk. Push the tip into the joint and pull the blade through the caulk. To give yourself greater control, hold the blade in your left hand if you are right-handed (the reverse if you are left-handed), and keep that hand in contact with the tub or shower base as you pull the tool along the joint. For very dry, stubborn caulk, use a chemical for caulk softening and removal, such as 3M Caulk Remover, as directed by the manufacturer.

3. Repeat steps 1 and 2 as needed until the joint is open and there is no caulk on either the fixture or the wall surface. You may find an excess of caulk on the wall near the fixture, well outside the joint, left over from previous attempts to repair caulk or from too-heavy application of caulk. Remove all of this.

4. Use a hair dryer or heat gun at a low setting to dry out the joint.

5. Use a vacuum with a pointed attachment, an old toothbrush or another small brush to remove any loose bits of caulk from the joint. Apply painter's masking tape to the wall surface and the tub or shower pan immediately adjacent to the joint.

6. Hold the tip of your caulk tube or cartridge against a cutting board and cut off the tip at a 45-degree angle with a utility knife, removing about 1/4 inch (6 mm) to create a 1/8-inch (3-mm) hole.

7. Holding the caulk tube at an angle, squeeze caulk into the joint until you've slightly overfilled it, then run the tube along the joint. Adjust the pressure, the speed or both to get the desired result.

8. Smooth the joint. Use a plastic caulk-smoothing tool designed specifically for this task, or use the wetted tip of your finger. Ideally you should do this in a single pass, but you'll likely have to pause because your fingertip is leaving an excess of caulk outside the joint, or because you need to add caulk in some places.

9. Remove the masking tape immediately after smoothing the caulk, and smooth the joint again with a wet, soapy finger. Wait overnight before using the tub or shower, or at least as long as indicated on the caulk label.

Tips & Warnings

• Don't use grout to fill the joint between the tub and the wall. The different rates of expansion of these dissimilar materials, as well as movement caused by the weight of water in a tub, require a permanently flexible joint filler.
• Avoid patch jobs. Failure in one location indicates the likelihood of future problems. While it may be possible to caulk over failed sections, the bond between new and old caulk usually fails, and the results are unattractive.
• Use only caulk designated for tub and tile use, which is formulated for mildew resistance.
• Metal tools can easily scratch or chip the surfaces of tubs and shower bases.

[missmarfett]

on 4/16/2008 Exactly what is " the mess that results when water penetrates that protective barrier."? I recently moved into a place where the caulk around the shower floor was -- well mostly non-existant. The house is on a slab foundation, what do I need to fix?

[the_nolen_clan]

on 1/27/2007 I recently bought a house that had a tub that was not level in one back corner. It had black spots sections in some of the caulking. I stripped the caulking out, and fond that they caulked over the grout that was there. So I scraped it all out. I then used bleach water, and a hair dryer. The I used denatured alcohol to clean the seams. Then I used tub and tile caulk. However, I haven't leveled that corner yet. It is in the back left hand corner, and the service panel is at the opposite end. And it is surrounded by tile. The question is, will the mildew resistant caulk keep the mildew from restarting?

[dkstevens]

on 12/17/2006 This is more of a question. I have a tile shower that had moldy caulk at the junction of the wall and floor tiles that I removed. I followed instructions for recaulking and within a week the caulk had slid out of the joint. So I cleaned the caulk and used grout to fill the joint. This also lasted about a week before it started falling apart. This is getting frustrating. Does anyone have experience in this who can help?

[Valerie]

on 10/29/2006 Regarding Step 9, I caution against removing the tape too soon. I was using a product today (DAP Kwik Seal Kitchen & Bath Adhesive Caulk) between tub and tile, which is VERY soft. Can't feather-in spots; have to do entire stretch for smooth finish, and each pass creates more "excess" to deal with. Smoothing out excess, bumps, or gaps creates a mess that is near to impossible to neaten once the tape is up. The product label says to "clean up excess with a damp sponge before it skins over" which I would recommend doing BEFORE removing the tape.