In short
We cut out caulk that has gone moldy or pulled away, scrape loose grout, clean and dry the joints, and refill them so water can’t reach the wall behind the tile. New grout is matched to the old as close as faded grout allows.
Your photo checklist
- The joint where the tub meets the tile
- Grout lines with cracks or gaps
- Mildew that won’t scrub off
- A clean spot of grout for color
- Tiles that sound hollow when tapped
Covered on a Rosemead visit
- Old caulk cut out, and the joint cleaned and dried before new caulk goes in
- Tub, shower, sink and backsplash joints
- Missing or crumbling grout raked out and replaced in small areas
- A loose single tile reset when the wall behind it is solid
- The caulk line at toilet bases and kitchen counters
Outside what we take on
- Foundation cracks or wall movement.
- New walls, framing changes or opening up a wall.
- Full exterior repaints.
Original tile and the moisture behind it
Rosemead has 6,417 homes built in the 1940s and 1950s, about 42 percent of its housing (ACS 2020–2024). Some of those bathrooms still have their first tile, and a matching replacement can be hard to find, so keeping water out from behind it matters.
EPA puts it plainly in its mold and moisture guide: “The key to mold control is moisture control.” It adds that “It is important to dry water-damaged areas and items within 24-48 hours to prevent mold growth.” An open caulk line lets shower water into the gap every day, which is why the black spots keep coming back however often they’re scrubbed.
How a caulk and grout job goes
Remove the old material
Caulk is cut out with a blade and tool, and loose grout is raked out to an even depth.
Clean and dry
We wash off soap film and mildew and let the joint dry. Caulk over damp or dirty joints peels early.
Fill
Grout is packed into the joints and tooled. Caulk goes in as one steady bead, pressed into the corner.
Cure
We tell you how long to wait before the first shower, usually a day for caulk, and longer for some grouts.
When the tile is outside our scope
Tile that sounds hollow over a wide area, a soft wall behind it, or water showing up in the room on the other side of the wall means the backing may be wet. Opening and rebuilding that section is outside our scope, and we can recaulk and touch up around it afterward.
While we’re out for this, Rosemead customers often add shower drain cleaning, rental turnover repairs, shower door repair, broken tile repair, shower valve and cartridge replacement, bathroom exhaust fan replacement, shower head and tub spout replacement or light fixture replacement.
Photos for a caulk quote
Close photos of the joints that are failing and one wider shot of the tub, shower or counter. Text them to (310) 628-9399.
Caulk and grout questions
Why is the caulk cracking along my backsplash?
The counter and wall move slightly. We cut out old caulk and use a flexible silicone.
Why does my caulk turn yellow?
Some acrylic caulks yellow with sun or cleaners. Silicone holds color better.
How much does caulking and grout repair cost?
It depends on the length of joints and grout area. Send a photo.
Can you seal the grout after it is replaced?
Yes. New cement grout can take a penetrating sealer once it has cured, which slows staining in shower joints.
Is the white crust on my tile grout a problem?
That is usually mineral left behind by hard water drying on the surface. A mild descaler and a soft brush take most of it off without harming the grout.
Do you caulk around kitchen sinks and counters too?
Yes. The joint between the backsplash and the counter, and around an undermount or drop-in sink rim, wears the same way.
Why does my tub caulk turn black so fast?
Mildew grows in moisture and soap film. Running the fan during showers and wiping the corners dry helps it last.
Should the tub be full of water when you caulk it?
For some tubs, yes. Filling it settles the tub so the joint does not stretch the bead the first time you bathe.
Can you match my grout color?
Close, but not always exact. We bring a few colors to compare against dry grout. Old grout has often darkened, so an exact match is not always possible.
Caulk or grout between the tub and the tile?
Caulk. That corner moves, and grout there tends to crack.
Will I hear from you before you show up?
Yes, you get a text before we head over.
What if the wall behind the tile is soft?
We stop and show you before doing anything more.
Can you do it while the place is empty?
Yes, with a key, a lockbox code, or a tenant letting us in.
What if the new caulk peels?
Let us know. If something isn’t right after the job, we come back and take care of it.
Can I regrout with a grout removal tool myself?
For a few joints, yes. A hand grout saw works for a few short joints, but it is slow and easy to chip tile edges. For a whole tub surround, we use an oscillating tool with a carbide blade, then clean, regrout and seal it.
Is cleaning grout enough, or should it be regrouted?
Cleaning removes surface stains. If the grout is cracked, crumbling or missing, it needs to be removed and replaced.
Worth a read: what our recaulking tubs and sinks guide says about caulking and grout repair.
Serving Alhambra or San Gabriel too? See our page on caulk and grout repair in Alhambra and the one on tub and tile caulking in San Gabriel.
Jobs that pair with this one
- Broken tile repairTile.
- Shower door repairDoors.
- Shower head and tub spoutFixtures.
- Bathroom exhaust fan replacementMoisture.
Caulk and tile tips for Rosemead homes
- Replacing cracked, moldy caulk around the tub and sinkWhen old caulk needs replacing, why caulking over it does not work, and how we strip and recaulk tubs, showers and sinks in Rosemead bathrooms.
- Hard water scale on faucets, aerators and shower headsHow hard-water scale clogs aerators, wears faucet cartridges and stains fixtures in Rosemead homes, plus the cleaning you can do and repairs we handle.
Jobs like this one are everyday work for our Rosemead handyman service, from the blocks off Garvey Avenue to the streets near Rosemead Park. A photo by text gets you a quote first.
Part of wall patching and paint touch-ups. You can also browse all our services or read about repairs in postwar Rosemead homes.