Is it necessary to power wash a deck before waterproofing it?

If it is a new deck, then no.





If it has been in place for a while, it depends on whether the aging or mold if present, is something you want to seal in place before treating it?





There are claeners that don't require power washing, just a brush to apply and scrub if the buildup isn't real bad. (Buy a brush on a hnadle like for washing a car, so you don't have to do this on your knees.)Is it necessary to power wash a deck before waterproofing it?
Not sure it's absolutely necessary, but every deck I've seen with any age at all to it has a buildup of dirt, gunk, junk that floats around outside that certainly dulls the look of the wood. If you want it to look more like new, then, yes, it's necessary. You can rent a fairly powerful power washer at most any rental store, for a fairly minimal amount.Is it necessary to power wash a deck before waterproofing it?
yes you need to get the dirt %26amp; grim out !
If you do power wash take care not to use to much pressure. It is possible to do a lot of damage to wood decks with a pressure washer.