Can Pressure Washing Damage Siding?

18 April 2019

Cleaning siding is one of the most popular uses for pressure washing as it's one of the best ways to maintain the look of your home in Florida. Regular pressure washing will keep your siding free of dust dirt, mold and other debris that may accumulate. Even though it's a popular cleaning method, many of our Tampa Bay area clients, or clients near us in Land O'Lakes, wonder if pressure washing will damage their siding.

The answer is, yes, it can damage siding, yet the type that you have on your home will determine how susceptible it is to damage. In addition, you have other elements to consider when pressure washing the sides of your home, including paying attention to the landscaping and grass immediately adjacent.

How to Clean Siding With a Pressure Washer

As with any other pressure washing job, preparation is key. Before beginning, check the condition of your siding as well, as some water is bound to indirectly splash on the panes. Check for cracks where water could penetrate and note how the planks on long walls overlap. For the windows, make sure that all glazing and caulking are intact. If you see any looseness or questionable spots, make repairs and delay your pressure washing job for several days to be sure those repairs are sound.

Wet down the soil near the siding to help dilute chemicals in the soap used for cleaning so your bushes and plants won't absorb them as readily. Cover landscaping with plastic sheeting to protect it from the forceful blast of water.

Most siding will benefit from an application of detergent before washing. Choose a general purpose cleaner to prevent root and leaf damage to nearby landscaping. If some of your siding has begun to show signs of mildew, prepare a mixture of one part household bleach to 10 parts water and apply it to the affected area. Wipe it off with a sponge and clean water before applying detergent.

When it's time to apply detergent, turn your pressure washer to a low setting to allow the soap to sink into the siding. Begin to spray the siding, working from the bottom up. The size of the area you work on depends on weather conditions as you don't want the detergent to dry. Generally, you should let it sit for two to three minutes before switching to a higher pressure and rinsing the detergent off. The pressure here should be about 1,200 psi to 1,300 psi. For both detergent application and the power washing portion, you should use a wide angle nozzle.

For the first rinsing pass, work from the bottom up without actually aiming the nozzle upward. Once you've accomplished this, it's time for a final rinse. Using the same pressure, work this time from the top down, this time standing about 10 inches away and pointing the nozzle downward. If an area has difficulty coming clean, you can step a little closer to the siding, but do so slowly because of the possibility of damage. For the second pass, you can switch to a nozzle with a 15-degree to 20-degree angle to provide a stronger stream. When finished, use a towel to wipe down residue on inner and outer corners and to help absorb moisture in sensitive areas.

Tips for Pressure Washing Siding

One of the dangers of pressure washing is the possibility of water can get underneath the siding and build up in your walls or in the attic, which in turn, can lead to mold growth. Follow these tips to minimize any possible damage:

  • Never hold the wand at an upward angle as this increases the chances of
  • water getting in behind the siding
  • Angle the nozzle down and away from windows and doors and take extra
  • caution near these areas, especially when screens are present
  • Avoid spraying electrical components directly
  • Use biodegradable detergent, if possible

Siding Types

Different types withstand pressure washing in different ways. Vinyl siding is pliable and generally withstands pressure washing well. The same goes for fiber cement siding. Wood clapboard can withstand the stream of pressure well too, however, if your home was built prior to 1978 have the exterior paint tested first to determine whether any lead is present. Pressure washing can dislodge lead paint, allowing it to settle in your soil where it will never break down.

Bigger problems arise with aluminum as strong streams of water can create dents. Shingle siding is even more of a problem as a strong blast of water can knock off individual shingles. Never pressure wash this type.

Get Our Professional Pressure Washing Help

If you're set on pressure washing your siding and are worried that you don't have the skills, you can also let a professional do the job. Edwins Pressure Washing Land O'Lakes can provide you with a FREE Quote for the job and ensure that your landscaping as well as your home won't be damaged in the process.