How often should you recaulk a bathtub or shower?

Short answer

Check every 6 to 12 months; replace it when it cracks, usually every few years. The caulk is the flexible bead where the tub or shower pan meets the tile and where the tile meets the wall at the corners. Looking takes a minute. Stripping the old bead and laying a new one is a 60 to 120 minute job with $5 to $15 in materials, and the result decides whether water stays in the shower or gets into the wall.

Why it matters

Tile and grout are hard. A tub is hard. The joint between them moves a little every time someone steps in, as the tub flexes and the house shifts with the seasons. Grout cracks under that movement, which is why the joint gets caulk instead: caulk stretches.

But caulk ages. It dries, shrinks and pulls away from one side or the other, and mildew grows in the gap. Every shower sends water down the tile and into the crack. The water soaks the drywall or backer board behind the tile, and from there into the wood framing and the floor. The first sign is usually mildew that won't scrub off, which is growing from behind the bead. By the time the floor outside the tub feels soft, the repair involves tearing out the wall.

When to do it more often

The index gives no exceptions to the schedule, because the schedule is already a check rather than a replacement. What changes is how soon the check turns into a recaulk:

A shower used by a big household every day sees far more water and more movement, so its caulk fails sooner.
A tub that flexes under a heavy load, as some fiberglass tubs do, works the joint harder.
A new bead that cracks within a season was laid over a wet or soapy surface, or was the wrong caulk, and needs redoing properly rather than waiting.

What you need

A utility knife or a caulk removal tool, to cut and scrape out the old bead
A caulk gun
Painter's tape, to mask both sides of the joint for a clean edge
Pure silicone caulk, or a kitchen-and-bath caulk with a mildew inhibitor

Steps at a glance

Slice along both edges of the old bead and pull it out, scraping the stubborn bits with the tool.
Scrub the joint with a cleaner that kills mildew, rinse, and let it dry completely, overnight if you can.
Run painter's tape along both sides of the joint, leaving a narrow gap for the bead.
Cut the caulk tube's tip small, fill the gap in one steady pass, and smooth the bead with a wet fingertip.
Pull the tape while the caulk is still wet.
Keep the shower dry for as long as the tube says before anyone uses it.

You're done when the bead is smooth, stuck to both sides, and has cured dry to the touch.

Signs it's overdue

Cracks or gaps in the caulk, especially along the tub edge where the joint moves most.
Mildew that won't scrub off, because it's growing from behind the bead rather than on it.
Caulk peeling away from the tile in a strip.
A soft floor near the tub, which means water has been getting through for a while.

DIY or pro

This is a moderate job. The skill isn't in applying the caulk, it's in removing every bit of the old bead and getting the joint truly dry before the new one goes on. Caulk laid over old caulk or a damp surface lets go within months. Give the removal and drying most of your time, and the bead itself takes a few minutes.

A handyman charges $150 to $300 to recaulk a tub or shower. That's reasonable if you've tried once and the bead keeps failing, or if the joint is wide and uneven and needs a backer. If the floor is already soft, you need more than caulk, and the handyman can tell you how much more.

FAQ

How do I know if my shower needs recaulking?

Look for cracks, gaps, or a strip of caulk pulling away from the tile. Mildew that won't clean off is the other sign, since it means water is getting behind the bead.

Can I put new caulk over old caulk?

No. The new bead sticks to the old one, not to the tub and tile, and fails as soon as the old bead lets go. Strip it all out first.

What kind of caulk should I use in a shower?

Pure silicone or a kitchen-and-bath caulk with a mildew inhibitor. Both stay flexible and stand up to constant water. Plain painter's caulk doesn't.

How long does caulk need to dry before showering?

Read the tube. Silicone needs the longest, and a shower taken too soon washes out the bead or leaves it soft.