A: Absolutely. One of the most common mistakes is to apply a stain or sealer to a dirty deck surface. Even if the deck is relatively new, there are certain types of wood that require cleaning. That’s why it is very important that we perform a wood evaluation to determine if cleaning is necessary even if it’s new wood.
https://deckmaster-us.com/faq/
The only way to clean a deck prior to a new coat of stain and sealer is to apply water and cleaning solution (or just water) and scrub as well as power-wash the surface to both clean and strip away any remaining layers of protective sealer.
http://homeguides.sfgate.com/soon-after-cleaning-deck-can-stain-seal-78024.html
Pressure treated wood decking is often delivered still wet with preservative. It needs time to dry out before finishing, so the stain will absorb into the wood. How long you need to wait before staining will vary depending on: 1  The moisture content in the wood.  Whether the deck is in the sun or shade.
http://www.todayshomeowner.com/video/how-long-to-wait-before-staining-a-new-wood-deck/
While you can leave the deck as-is, you can also stain and seal it for increased durability. Over time, the deck needs to be cleaned and power-washed to apply new layers of stain and sealer, and knowing the right time to reapply things after washing leads to longer-lasting coverage.
http://homeguides.sfgate.com/soon-after-cleaning-deck-can-stain-seal-78024.html
Pressure treated wood decking is often delivered still wet with preservative. It needs time to dry out before finishing, so the stain will absorb into the wood. How long you need to wait before staining will vary depending on: The moisture content in the wood.
http://www.todayshomeowner.com/video/how-long-to-wait-before-staining-a-new-wood-deck/
A: No. Power washing by itself will only blast off the dirt from the wood surface. Too much pressure will also raise the grain of the wood and cause splintering and severe damage. 80% of decks today are sealed or stained.
https://deckmaster-us.com/faq/
Pressure treated wood decking is often delivered still wet with preservative. It needs time to dry out before finishing, so the stain will absorb into the wood. How long you need to wait before staining will vary depending on: 1  The moisture content in the wood. 2  Whether the deck is in the sun or shade.  The climate and weather conditions in your area.
http://www.todayshomeowner.com/video/how-long-to-wait-before-staining-a-new-wood-deck/
If standing water is left after you power wash and scrub the deck, squeegee it off the surface of the wood or soak it up with towels to avoid soaking into one place. For best results, choose days during the middle of summer to speed up your drying time. This Old House: Clean and Stain a Deck.
http://homeguides.sfgate.com/soon-after-cleaning-deck-can-stain-seal-78024.html
Average Drying Time. As a general rule, 48 hours is sufficient drying time for a newly washed deck. But this also assumes optimal drying conditions, such as a sun-facing deck. If you are on the shadow side of the home where little to no sunlight reaches, wait at least 72 hours before applying any stain or sealer.
http://homeguides.sfgate.com/soon-after-cleaning-deck-can-stain-seal-78024.html
A: It depends on the finish you applied. 95% of stains/sealers need to be stripped prior to re-applying another coat. There are only a few products that don’t require this procedure. A light cleaning to etch the surface is all that is necessary.
https://deckmaster-us.com/faq/
how long after deck wash before staining
It takes 72 hours for staining after deck wash. At 72 hours  after deck wash before staining.