Have you ever used a power washer and witnessed the short work it can make of cleaning away moss, dirt, or oil stains from a concrete driveway or walkway? If so, you might have then wondered if the power washer can also wash an indoor bathtub or shower.
Tubs and showers are subject to constant moisture and soap residue, which makes them susceptible to a buildup of scum and grout joints discolored by mold and mildew. If your basin, pan, or surround have not been cleaned regularly, it can reach a level of dirtiness that takes many hours of hand-scrubbing with a bleach cleanser to restore it to a like-new condition. Any method of speeding this process is extremely welcome.
How a Power Washer Cleans a Tub or Shower
Water coming into the house or to exterior hose bibs has a pressure of about 40 to 45 psi. Garden hoses can increase that pressure to 100 to 200 psi. But when hooked up to a power (or pressure) washer, that water pressure can increase ten-fold over the garden hose pressure.
The power washer jets away grime on the tub or shower through pressurized water alone. No scrubbing or cleansers are involved.
By running out of an exterior hose bib and keeping the power washer outside, you avoid the leaking or flooding problems that you may encounter by locating the power washer inside.
Since tubs and showers have drains, all of the water (except for backsplash) expended by the power washer is safely drained away.
Precautions and Safety Considerations
Can a pressurized power washer quickly clean a shower or bathtub shower enclosure? The answer is yes—you can harness your pressure washer's intense water jet and apply it to indoor tile. Used correctly, a pressure washer can clean better than abrasives, scrubbing, or steam cleaning.
But many conditions and cautions must first be considered:
- Tile, grout, and caulked seams must be intact, with no gaps. Pressurized water can easily force its way into tiny crevices and get to the wall materials behind the tile, where the moisture can do serious damage. Any water inside the wall will cause rot and mold, which can lead to expensive repairs to correct structural damage and eliminate health risks. Use the power washer method only if all the tile, grout, and caulk joints are perfectly intact.
- Pressure washing indoors is very wet. Despite the fact that 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 power washer next to an open window.
- Use an electric-powered power washer. The bathroom should have a window through which the hose of the pressure washer can be run. The pressure washer should be set up outdoors. Even with electric pressure washers, it is generally not practical to set up the machine inside the bathroom.
- Pressure washing does not replace routine cleaning. The pressurized spray of a power washer can damage grout and caulked seams, and it should be reserved only for those very serious cleaning jobs where a shower has been neglected for a long time and hand-scrubbing is prohibitively difficult.
- Do not power wash if the bathroom floor is made of a water-sensitive material. Solid wood, engineered wood, bamboo, carpet, laminate, cork—all of these flooring materials are likely to be damaged by the unavoidable moisture that is part of pressure washing. 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. The best flooring materials are water-proof ceramic tile or vinyl flooring; all others could be damaged by moisture.
- Do not attempt to power-wash ceramic or porcelain tile floors. This is a technique that works only for bathtub shower walls.
- Do not power-wash ceramic tile that has been refinished or coated with paint or a refinishing or reglazing product. It is likely that the power washer will chip away areas of the coating.
Power 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.
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 it is critical that you 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 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 beach or bath towels nearby to mop up the water.
Set Up the Pressure Washer Outdoors
Place the power 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 in the pressure washer to the nearest GFCI outlet.
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.
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.
To minimize overspray, keep the spray at a 45-degree angle to the wall and always point down or sideways. You want as much water as possible to drain back into the tub and down the drain.
Hand-Clean the Bottom Areas
The bottom edge of the tile, where the tile meets the tub or shower floor, is 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 tile at the bottom should be cleaned by hand scrubbing with a nylon abrasive 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 collected on the tub deck, soap dishes, and other horizontal surfaces. Dry the bathroom floor with a mop or clean rags, as needed.