Power washing, then sealing a deck.

My sister is having a contractor power-wash her deck, then seal it the next day. I was under the impression that power washed wood took a bit longer than that to dry. I’m basing this on a do-it-yourself book I read on painting wood siding on houses. The book says you should wait several weeks before painting after pressure washing.

Is there a difference with the sealant typically used on a deck? Was the book being overly cautious? Should the contractor wait a bit before sealing?

FWIW, I have always heard that, and that is how I have always done it.

Many of the new sealers may be applied the next day after a good power washing.