Cleaning Shower Grout: Daily, Weekly and Deep Cleaning Routines

To keep shower grout clean, squeegee the walls and floor after every shower, wash weekly with a neutral or mildly alkaline bathroom cleaner and a nylon brush, and deep clean every one to three months with an alkaline degreaser that dissolves soap scum and body oil. Rinse thoroughly and let the shower dry with the fan running.

What actually builds up on shower grout

A shower is a cycle of wetting, soiling and slow drying, repeated once or twice a day. The deposits on the grout are not one thing but several, and they stack.

• Body oils and skin cells. Sebum and skin lipids wash off with every shower and coat the lower walls and floor. They are oily, slightly sticky and darken over time.
• Soap scum. Bar soap is made of fatty acid salts. In water containing calcium and magnesium, those react to form insoluble calcium and magnesium soaps: the gray-white, waxy film called soap scum. Body washes and shampoos produce less of it, but conditioners and oils add their own residue.
• Hard water minerals. As water evaporates, dissolved calcium carbonate and other minerals stay behind as white spots and scale, often bound into the soap film.
• Biological growth. The oily, mineral-rich film holds moisture and nutrients. Mildew (black or green spots) and pink bacterial film colonize it, especially in corners and low joints that dry last.

Cement grout is porous and sits slightly below the tile face, so the film collects in the joint and partly soaks in. That is why grout darkens faster than the tile around it. For the chemistry of the mineral side, see soap scum and hard water on grout; for black spots and regrowth, see grout mold and mildew. This article is about the routine that keeps all of them from building up.

The routine at a glance

Heavily used showers, hard water and textured or handmade tile push you to the short end of each interval. Epoxy-grouted showers sit at the long end; their care is covered in cleaning epoxy grout.

The daily squeegee: why it works

Soap scum and mineral scale form when water evaporates on the surface and leaves its dissolved load behind. A squeegee removes most of the water before that happens, which means the minerals and soap go down the drain instead of onto the grout. It also cuts the time the joints stay wet, and drying time is what controls mildew.

• Work from the top of each wall down, overlapping strokes, and finish with the floor toward the drain.
• Pay attention to the bottom two rows of wall tile and the floor perimeter. They stay wet longest and soil first.
• Leave the door or curtain open and run the exhaust fan for 20-30 minutes after showering. A shower that is dry within a couple of hours rarely grows mildew.
• A daily spray of a no-rinse shower product is optional. If you use one, choose one labeled safe for grout and stone, and do not use it as a substitute for squeegeeing.

The weekly wash

Weekly cleaning removes the thin film before it bonds. A neutral or mildly alkaline bathroom cleaner is enough at this stage. Avoid products that rely on acids for "soap scum and lime" claims as an everyday cleaner on cement grout: frequent acid exposure slowly erodes the joint surface and damages calcareous stone. For how pH affects each product family, see grout cleaners by pH.

• Rinse the walls with warm water from the hand shower.
• Spray the cleaner on the lower half of the walls and the floor, where body oil collects, and let it sit 3-5 minutes.
• Brush along the joints with a medium nylon grout brush. A long-handled brush saves your back on the floor.
• Rinse top down, then squeegee.

Step-by-step: deep cleaning shower grout

This sequence is for cement grout that has cured at least 28 days and for tile that tolerates mildly alkaline cleaners (glazed ceramic, porcelain, glass, and most sealed stone; test stone first). It removes the soap scum and body oil that the weekly wash leaves behind. The general method, including the escalation ladder, is in how to clean grout.

1. Clear and ventilate. Remove bottles, mats and caddies. Turn on the exhaust fan and open a window or door. Wear nitrile gloves and eye protection; alkaline cleaners splash when you scrub overhead.
2. Check for damage first. Look for cracked joints, missing grout, or soft areas you can scratch out with a fingernail. Deep cleaning will make those worse. Note them for repair, and clean around them gently.
3. Pre-wet with warm water. Warm water softens the oily soap film and keeps the cleaner from soaking deep into dry grout.
4. Apply an alkaline cleaner and let it dwell. Use a heavy-duty bathroom or tile degreaser in the pH 10-12 range, or a warm oxygen bleach solution, at the label dilution. Apply from the bottom up so it does not streak down dry tile. Keep it wet for 10-15 minutes, re-misting if it starts to dry.
5. Scrub joint by joint. Use a stiff nylon grout brush along each joint, then a white non-scratch pad on the tile faces. Work the lower walls and floor most. Soap scum should feel slippery as it releases, then the surface returns to a squeaky texture.
6. Rinse thoroughly, top down. Rinse with plenty of warm water from the hand shower or a bucket and cup. Rinse twice on the floor, where residue drains to and collects.
7. Treat what remains, one thing at a time. White scale that survived the alkaline wash is mineral. Black spots are mildew. Each has its own treatment in the linked guides. Rinse completely between treatments and never use chlorine bleach in the same session as an acid or ammonia product.
8. Squeegee and dry. Squeegee, then run the fan. Let cement grout dry for 24-72 hours before judging color or resealing.
9. Reseal if needed. If water darkens the dry grout within a few minutes, reseal following sealing shower grout.

Special cases in the shower

Stone showers

Marble, limestone and travertine etch on contact with acids, including vinegar and many "soap scum" sprays. Use only cleaners labeled safe for natural stone, keep the daily squeegee habit strict, and expect to reseal stone and grout more often. See grout for marble for why stone showers are handled differently.

Caulked corners and perimeters

The inside corners, the joint where the wall meets the tub or pan, and other changes of plane should be sealant, not grout. Silicone sealant cannot be cleaned of mildew that has grown into it; replace it. See grout vs caulk vs silicone.

Shower floors

Floor grout carries the most soap and oil, stays wet longest and gets the most foot abrasion. Clean it more often than the walls. If floor grout looks permanently wet or dark days after use, that is a water-under-tile symptom rather than a cleaning issue; shower floor grout explains the build-up behind it.

Steam cleaning

Steam lifts soap film and body oil well on sound grout and is a reasonable chemical-free option for the deep clean; see steam cleaning grout for the limits.