Let’s talk about the purpose of power washing a home. Here are some things you should know.

  • Why power wash
    • The purpose of power-washing is to simply clean the substrate of dirt, dust, mold, mildew, etc. It really isn’t intended to be a power “scraper”. Using it for this purpose can damage soft wooden substrates such as cedar, pine, etc. It can “Fur” and “Gouge” the wood by holding the wan to close to the substrate. If your using it to remove paint chips from the house, you had better plan on putting tarps 25 feet out from the house, or have a lawn vac available to vac up all the paint chips that will litter your yard. If this is a case with removing lead paint, “It is Illegal to do so!“. If you have young children that play in the yard, they may ingest some of the chips and end up with lead poisoning.  Lead poisoning causes nervous system disorders especially in younger children, which can result to physical and mental disorders, or even be fatal in the case of very young children.
  • What are you trying to accomplish
  • Using additives
    • Be careful when using additives, such as; “TSP” (trisodium phosphate), “bleach”, “Simple Green“, etc.,  that when used incorrectly can damage the substrate.
  • There is a correct “Method of Application”
    • Depending on the purpose there is a “method of application” that is correct for each purpose. Probably the most important thing to remember before using additives is to thoroughly soak the area where you intend on applying the additive. WHY? Soaking the area hydrates the wood and pushes the additives to the surface of the wood where you want them. That is what you’re trying to clean. The water that is soaked into the wood acts as a barrier to keep unwanted additives from remaining deep in the wood, and over time compromising the wood itself.
    • Be aware of the “Soft Wash Method” which was designed for cleaning roof tops. There is a difference between the roof shingles, and the soft cedar wood that is used for siding. While chemicals work well on roof shingles, left for long periods of time they will separate the glue used to bind the wood pulp together in the construction of siding. This is the process actually used in manufacturing paper.
    • Here is the process for pressure-washing the siding of a house
      • Thoroughly rinse the siding to hydrate it.
      • Apply the additives, and wash the siding with a brush. Remember, if you’re using a bleach mixture (typically 1-part bleach to 4-parts water) use a cleaner mixture at the same time. i.e. “Simple Green” Why? The beach is used to kill mold and mildew, while whitening the substrate. The additive such as “Simple Green” is a cleaner and will wash the substrate. They both should be used together if one is to use bleach. In the case of “Simple Green” you can use it alone with excellent results
      • Rinse the substrate thoroughly
      • Allow to dry thoroughly! Do no paint while the substrate is still wet  or damp!!
      • Apply the primer, and finish coat to a dry substrate.
      • NOTE: in the case of decks, one should consider using a “Brightener” before staining or painting.

Watch this short video on “wood brighteners”