Pressure washing is generally safe for vinyl siding, although it should only be done by a trained professional to ensure the work will not damage your siding. Vinyl siding is an incredibly strong material. Vinyl is made from polyvinyl chloride, or PVC, and can withstand pressures as high as 3000 psi without any risk of harm.
To properly wash your siding and avoid damage there are four main aspects to focus on:
1. Using the correct nozzles/tips on your pressure washer wand
2. Being the correct distance from the siding
3. The PSI and GPM flow of your pressure washer
4. Using the correct angles of approach
Pressure washers have a variety of tips/nozzles that can be attached to the wand. The wand is a gun-shaped mechanism that is held in the hand of the user and controls the water flow. At the end of this wand, there is a quick-connect mechanism that allows for different angled nozzles to be used for different pressures. These come in standard angles and colors. Black is 60°, white is 40°, green is 25°, yellow is 15°, red is 0°. The larger the angle, the lower the pressure will be at the surface of the siding. As pressure is calculated as pounds per square inch, the greater the value of square inches (surface area), the lower the pressure on the surface. Therefore, the lower the angle, the higher the risk of damage to the siding. To minimize risk and still get work done effectively, we need to strike the correct balance between these angled nozzles. At EcoWash, we recommend the 40° white tip for most vinyl siding washing work and the 25° green tip for harder stains. This is not an absolute rule as there can be other variables, but if you are a beginner or a homeowner with little to no experience with a pressure washer, this is our recommendation.
Our suggestion is to stay 8”-16” from the siding with the nozzle of your pressure washer wand. This distance should be maintained for adequate removal of dirt, algae, mold, and stains while avoiding oxidation removal, which is a serious eyesore and can be interpreted as “damage” despite being reversible. If your home is taller than one story, do not attempt to pressure wash the top of the home on a ladder. This is incredibly dangerous and can lead to serious injury. Pressure washers exert backward force and if you are on a ladder this can lead to you falling. Not only is pressure washing on a ladder dangerous, but it is also generally ineffective as the ladder is far too close to the siding at the top to get an adequate distance from the siding to avoid pressure washer damage. If you have a multi-story home, please contact a professional to get this done.
EcoWash recommends using a pressure washer between 2800-3500 psi on vinyl and a GPM flow of 2.5 - 4.0. While many individuals unfamiliar with pressure washing may think PSI to be the most useful measurement of pressure washer effectiveness, this is not the case. Gallon per minute flow will more accurately determine how effective your pressure washer will be at removing stains and working quickly. However, more is not always better because residential water systems generally have a flow rate of 4.0 GPM from an exterior spigot, meaning anything more than that will need a separate water tank to provide water. In regards to PSI, washing a house with a gas pressure washer between 2800-3500 psi and following the other advice in this article should prevent damage and be fairly efficient. An electric pressure washer will not work for this task as it is dramatically underpowered on top of the PSI ratings being rarely accurate and the GPM ratings being very low.
When siding is washed, one must keep an eye on the angle they are approaching the siding. Vinyl siding is generally overlapped away from the nearest door or point of entrance to the home for appearance reasons. Knowing this, it would be a good idea to wash so you are not getting water in between the gaps in the siding. If you do accidentally do this it should not be a concern as siding is just one small part of your wall structure with many other barriers to prevent water entry into your home but being careful is a good idea.
At EcoWash, we ensure our customers have no risk of damage to their siding by training our staff on the correct nozzles to use, angles to approach siding, and correct distance from siding to maximize efficiency and minimize the risk of damage. We have trained staff who can avoid problems and know how to fix any problem that may arise. However, just in case something were to go wrong, we have a million-dollar liability policy on every single one of our projects to guarantee the customer will never have a lasting issue from our service. We pride ourselves on the quality of our work.
If you are concerned about pressure washing damaging your siding, please get in touch with one of EcoWash’s local representatives to get your questions answered or an estimate on your pressure washing service. You can request an estimate here.