Should You Power Wash Your House Before Painting?

Paint bonds to the surface it touches. If that surface is a layer of grime or powdery old paint, the new coat is only as strong as that layer. Washing removes it so the paint can bond to sound material underneath.

Mildew is a special case. If it is painted over without being cleaned, it can keep growing under the new film and show through.

On older wood clapboards, very high pressure can gouge the wood, raise the grain and force water behind the siding and into the wall. That water then needs to dry out, and wet wood is the opposite of what you want under fresh paint.

Lower pressure with the right cleaning solution, a careful angle and enough distance cleans just as well on most homes. Vinyl, brick and concrete each need their own approach too.

Wood needs time to dry after washing. In good weather that is commonly a day or two, longer if it is humid or the wall stays in shade. Painting over damp wood is one of the quiet causes of early peeling.

A gentle wash every couple of years keeps the house looking fresh and slows down mildew and dirt buildup, which helps the paint last longer. Decks, walkways and fences benefit from regular cleaning too.

Washing is included as a prep step on our exterior jobs, and we also offer power washing on its own for siding, decks and walkways around Arlington and nearby towns. We adjust the pressure to the surface, especially on older wood.