Tub, shower and sink recaulking

Why caulk matters

Caulk seals the joints that move: where the tub meets the wall, where a counter meets the backsplash, where a sink rim sits on stone. Those joints flex as the house shifts and as a tub fills with water and settles. Grout cracks there; caulk stretches. When caulk fails, water runs behind the tile or under the counter, and the damage stays hidden until a tile loosens or a cabinet floor swells.

Signs it needs redoing

• Black or pink spots that come back after cleaning.
• Caulk peeling away from the tub or tile.
• Gaps you can slide a fingernail into.
• Cracks along the bead.
• Water on the floor after a shower with no other cause.

Doing it right

Laying new caulk over old caulk does not last; the new bead sticks to the failing one, not the surface. We cut out all the old caulk with a blade and remover, scrape the residue, clean mildew with a cleaner, and let the joint dry fully.

A dry joint is the step people skip, and it is the reason home caulk jobs fail in months. Then we tape both sides where it helps, lay a continuous bead of 100% silicone or a kitchen-and-bath sealant, tool it smooth, and pull the tape.

For tubs, we fill the tub with water before caulking so it sits at its loaded position. When the water drains, the bead is slightly compressed instead of stretched, and lasts longer.

Silicone or latex

Silicone stays flexible longest and sheds water best, which makes it our usual pick for tubs and showers. It cannot be painted. Siliconized acrylic is paintable and easier to tool, so we use it on trim and counters that meet painted walls. Color matters too: clear, white, almond and colors that match grout are common.

Cure time

Many silicone sealants call for about 24 hours before water touches them; we follow the cure time printed on the tube. We tell you the exact time on the tube. Using the shower too soon leaves soft spots that peel early.

Other spots worth sealing

While we are there, we check the joint where the toilet meets the floor, the escutcheons around shower valves, and the gap where the vanity top meets the wall. If grout itself is failing, see tile regrouting. If the shower valve drips behind the wall, see shower valve repair.

Mildew in a dry climate

Even in the valley’s dry air, bathrooms stay damp. Small bathrooms without a window or a working fan grow mildew fastest. Running a fan helps caulk last; see our bathroom fan page if yours is weak or loud.

Shower doors

Glass shower doors are caulked along the outside of the frame, not the inside, so water that gets past the door can drain back into the tub. Caulk on the inside traps water. We check the door frame and recaulk the right side.

Kitchen sinks

Undermount sinks are held by clips and adhesive and sealed with silicone. When that bead fails, water runs into the cabinet. We clean and reseal it, and check the clips while there.

Short visits

Recaulking a tub and a vanity usually fits in one short visit. It pairs well with a faucet swap or a toilet repair during the same visit.

Pink and black spots

The pink film around tubs is usually a bacteria that feeds on soap residue, not mold. Black spots in caulk are mildew growing into the material. Pink film cleans off; black spots inside caulk usually do not, which is why we replace stained caulk rather than scrub it.

Gaps too big for caulk

A gap wider than about a quarter inch needs a foam backer rod pushed in first, so the caulk bead is the right depth and does not sag. Very large gaps can mean the tub has settled or the wall has moved. We check for that before sealing.

Showers with stone

Natural stone needs a sealant labeled safe for stone, since some caulks stain marble and limestone at the edges.

Color match

We bring white, almond, clear and a few grout-tone colors so the new bead matches the tub and tile. If you want a specific color, tell us ahead of time and we pick it up before the visit.

Tubs that flex

Acrylic and fiberglass tubs flex more than cast iron. Caulk around them cracks sooner if the tub is not well supported underneath. When a bead keeps failing at the same spot, we look at the tub for movement before recaulking again.

Rental turnovers

Fresh caulk is one of the cheapest ways to make a rental bathroom look clean for move-in photos. Stained, peeling caulk makes a clean tub look dirty. We recaulk tubs, vanities and kitchen sinks in one visit during a turnover, and leave a note of the products used.

Caring for new caulk

Wipe the bead dry after showers for the first week, clean with a mild cleaner, and avoid scrubbing it with abrasive pads.

Photo checklist