How to Clean a Bathtub or Shower With a Pressure Washer
Deep Cleaning Your Shower Safely Without Causing Damage
Tubs and showers are susceptible to scum buildup and mildewed grout joints. A pressure washer can make short work of cleaning away moss, dirt, or oil stains from a concrete driveway or walkway, so what about an indoor bathtub or shower? If it looks like your tub basin, shower pan, or tub surround needs many hours of hand-scrubbing with a bleach cleanser, a pressure washer can do the cleanup quickly but with several caveats and words of caution.
Before You Begin
It is not advisable to use a pressure washer indoors. But you can use a pressure washer indoors to clean a shower or bathtub if you run the pressure washer from an exterior hose bib (outside hose line) and keep the pressure washer device outside to avoid leaking or flooding problems from the device. At least tubs and showers naturally drain water away, helping drain out the water.
Theoretically, a pressure washer can clean grimy indoor surfaces in a bathtub or shower. You can harness the tool's intense water jet and apply it to indoor tile or fiberglass surrounds. When used correctly, a pressure washer can clean better than abrasives, scrubbing, or steam cleaning. But there are issues to consider first.
Water coming into the house or to exterior hose bibs has a pressure of between 40 to 60 psi. Garden hoses can increase that pressure to 100 to 200 psi. But when hooked up to a pressure washer, that water pressure can increase ten-fold over the garden hose pressure. A pressure washer could therefore jet away grime on the tub or shower through pressurized water alone—no scrubbing or cleansers would be needed.
Before undertaking such as project, keep in mind the sheer power of a pressure washer. This tool can strip paint from wood, remove rust from metal, and tear open skin, causing severe injury. Used indoors, pressurized water can quickly force its way into tiny crevices and get to the wall materials behind the tile, where the moisture can do severe damage. Any water inside the wall will cause rot and mold, leading to expensive repairs.
If you pressure wash tile, grout, caulked seams, porcelain, or fiberglass surfaces, each surface must be fully intact, with no gaps. Even the smallest area of loose grout can be blown loose and opened up to admit water into wall cavities. And there are other issues to keep in mind:
- Pressure washing indoors is very wet. Even though you are cleaning inside a tub or shower stall, you can expect overspray, even if you are very careful.
- Never use a gas-powered pressure washer indoors. It is also unsafe to set up a gas-powered pressure washer next to an open window. Instead, use an electric-powered power washer. The bathroom should have a window through which the pressure washer's hose can be run. If possible, the pressure washer should still be set up outdoors to prevent water from escaping.
- Pressure washing does not replace routine cleaning. It should be reserved only for those tough cleaning jobs where a shower has been neglected for a long time and hand scrubbing is prohibitively difficult. The pressurized spray of a pressure washer can damage grout and caulked seams.
- No matter how much you try to isolate the tub/s shower enclosure or protect the floors, it is almost certain they will get damp. Do not pressure wash if the bathroom floor is made of a water-sensitive material. Solid wood, engineered wood, bamboo, carpet, laminate, and cork—all of these flooring materials are likely to be damaged by the unavoidable moisture of power washing. The best flooring materials are water-proof ceramic tile or vinyl flooring; water could damage all others. And do not attempt to power-wash ceramic or porcelain tile floors. The technique described here works only for bathtub shower walls.
- Do not pressure wash a tub or surround that has been refinished or coated with paint or a refinishing or reglazing product. The pressure washer will likely chip away areas of the coating.
- Pressure washing can shatter glass. Pressure washing is not recommended to clean glass shower doors.
Pressure washing your tub or shower requires considerable thought, preparation, and cleanup. There are many instances where it is not advised. Reserve this method only for those situations where it is appropriate—extremely dirty tile where the grout and caulk seams are in good condition or very grimy fiberglass or acrylic surrounds and tubs.
How to Clean a Bathroom With a Pressure Washer
What You'll Need
Equipment / Tools
- Electric pressure washer with fan tip
- Garden hose
- Mop or rags
- Nylon abrasive pad
- Plastic sheeting
- Duct tape
Prepare the Space
Overspray is an inevitable byproduct of pressure washing, but you can take precautions against this. Plastic sheeting on the floor and ceiling can help keep the space drier, but it will never remain completely dry. While you must try to control the overspray, be prepared for moisture throughout the bathroom.
One way to limit overspray is to run a wall of plastic sheeting in front of the tub or shower, holding it to the ceiling with ZipWall poles or tape. Tuck the bottom of the plastic into the tub or shower so that the water will drain back into the tub.
You can also lay plastic sheeting across the floor and extend it 12 inches up the wall to protect the lower section of the walls and prevent water from getting under the baseboards. It's also a good idea to have plenty of large towels nearby to mop up the water.
Set up the Pressure Washer Outdoors
Place the pressure washer outdoors, as close as possible to a bathroom window that gives you access to the bath or shower. Connect a garden hose to the pressure washer. Feed the pressure washer hose and nozzle through the window and into the bathroom. Plug the pressure washer into the nearest GFCI outlet. Most sprayers have lengthy extension hoses that allow using the sprayer on second-floor bathrooms even when the motor unit is on the ground below.
Never run a gas-powered pressure washer indoors. Gas engines emit deadly carbon monoxide gas and must be fully ventilated at all times when running.
Adjust the Spray and Pressure
Attach a fan-spray tip to the pressure washer spray nozzle. Never use a pinpoint tip, which can easily damage the grout. Set the spray pressure at a low setting. If necessary, you can inch up the pressure if the initial setting is too low, but use only as much pressure as needed to clean the tile or surround material.
If you notice grout chipping or flaking off under the stream of water from your pressure sprayer, stop working. The sprayer may likely begin to dislodge more grout and possibly even the tiles themselves. This method only works on tile walls that are very solidly attached, with grout that is completely intact.
Spray From the Top Down
Begin by spraying at the top of the tile wall, working in horizontal runs. After you finish a complete pass, move down about 6 inches and do another pass. By starting at the top, you ensure that debris keeps moving downward, away from cleaned areas.
Hand-Clean the Bottom Areas
The bottom edge of the tile or surround, where it meets the tub or shower floor, is usually sealed with caulk rather than grout. As you work your way down to this caulk joint, stop spraying a few inches above the caulk to prevent damaging it. The remaining portion of the surround should be cleaned by hand scrubbing with an abrasive nylon pad.
Turn off the pressure washer, and feed the hose back outside. Remove the plastic sheeting and clean the tub or shower with a sponge to remove any debris and residue that is collected on the tub deck, soap dishes, and other horizontal surfaces. Dry the bathroom floor with a mop or clean rags, as needed.
What's the difference between power washing and pressure washing?
Power washing and pressure washing both use high-pressure water. The difference is that power washers also use hot water or steam, heating the water from the high-pressure nozzle.
How do professionals clean showers?
Professional cleaners use bleach, vinegar, or other cleansers to get mold, mildew, soap scum, and lime scale off the bath and shower surfaces.
What should you not pressure wash?
Brown, Phil, et al. High-Pressure Injection Foot Injury. Foot & Ankle Surgery: Techniques, Reports & Cases, vol. 2, no. 1, 2022, p. 100110. doi:10.1016/j.fastrc.2021.100110
NIOSH Warns of Deadly Carbon Monoxide Hazard from Using Pressure Washers Indoors. The National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention.
Preventing Carbon Monoxide Poisoning From Small Gasoline Powered Engines and Tools. The National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention.