Blotchiness after pressure washing - Deck Cleaning Questions and Answers https://forum.deckstainhelp.com/deck-cleaning-questions-and-answers/blotchiness-after-pressure-washing/ Deck Stain Help Forum Discussion Board en-US Tue, 30 Jun 2026 14:51:59 +0000 wpForo 60 RE: Blotchiness after pressure washing https://forum.deckstainhelp.com/deck-cleaning-questions-and-answers/blotchiness-after-pressure-washing/#post-14896 Tue, 17 Sep 2024 06:23:48 +0000 The sealer is a semi-transparent with a moderate colour in it. It's. The company advertises that it provides durable protection from sun damage.

Also, I didn't use a cleaner/brightener when I pressure washed....only water, followed by a round of scrubbing with a strong broom. Since then I've read some of your posts where you suggest using a cleaner/brightener. But if I go over it again with only water to remove the gray, then do a bit of a sanding and then apply the semi-transparent sealer, would that be sufficient?

That means it is a stain, not a sealer. Sealers are clear. If it has color in it, then it is considered a stain. You should use a deck cleaner, and then light pressure wash off. Brightener last. You probably do not need to sand it.

 

]]> Deck Cleaning Questions and Answers Scott Paul ~ Restoring Wood & Decks Since 1993 https://forum.deckstainhelp.com/deck-cleaning-questions-and-answers/blotchiness-after-pressure-washing/#post-14896 RE: Blotchiness after pressure washing https://forum.deckstainhelp.com/deck-cleaning-questions-and-answers/blotchiness-after-pressure-washing/#post-14895 Mon, 16 Sep 2024 17:13:37 +0000 The sealer is a semi-transparent with a moderate colour in it. It's. The company advertises that it provides durable protection from sun damage.

Also, I didn't use a cleaner/brightener when I pressure washed....only water, followed by a round of scrubbing with a strong broom. Since then I've read some of your posts where you suggest using a cleaner/brightener. But if I go over it again with only water to remove the gray, then do a bit of a sanding and then apply the semi-transparent sealer, would that be sufficient?

]]> Deck Cleaning Questions and Answers pd512 https://forum.deckstainhelp.com/deck-cleaning-questions-and-answers/blotchiness-after-pressure-washing/#post-14895 RE: Blotchiness after pressure washing https://forum.deckstainhelp.com/deck-cleaning-questions-and-answers/blotchiness-after-pressure-washing/#post-14892 Mon, 16 Sep 2024 06:37:32 +0000 Do you realize that sealing wood offers no UV protection? It must have a color if you want UV protection from graying: https://www.deckstainhelp.com/will-a-clear-sealer-prevent-graying-on-deck/

]]> Deck Cleaning Questions and Answers Scott Paul ~ Restoring Wood & Decks Since 1993 https://forum.deckstainhelp.com/deck-cleaning-questions-and-answers/blotchiness-after-pressure-washing/#post-14892 RE: Blotchiness after pressure washing https://forum.deckstainhelp.com/deck-cleaning-questions-and-answers/blotchiness-after-pressure-washing/#post-14890 Mon, 16 Sep 2024 00:49:33 +0000 Thank you Scott.

Just to clarify, we're actually going to be sealing it, not staining it. Not sure if that makes a difference in regards to the advice.

]]> Deck Cleaning Questions and Answers pd512 https://forum.deckstainhelp.com/deck-cleaning-questions-and-answers/blotchiness-after-pressure-washing/#post-14890 RE: Blotchiness after pressure washing https://forum.deckstainhelp.com/deck-cleaning-questions-and-answers/blotchiness-after-pressure-washing/#post-14888 Sun, 15 Sep 2024 06:20:57 +0000 Hi,

We have a deck that is 7 years old. Yesterday for the first time ever, I decided to clean it with a pressure washer. Next I plan to seal it before the winter. I live in Canada and our winters are long and we get a lot of snow.

I read other posts on this forum and although it's a bit hard to tell from the other users' photos, if I had to diagnose it I think I pressure-washed too harshly. First-timer here. I think I went too close and didn't feather out.

Part of the deck has become blotchy, i.e. there's the original greyish areas, and now some areas that are yellow.

I've uploaded the photos to my Google Photos account (I keep getting an error when I try to attach photos to this forum post). Photos: https://photos.app.goo.gl/zfns7sJv41Abjpw29

Do I now need to sand it? It's not a large area...only 8' x 5' so I could do it with a handheld sander.

What if I don't sand it and just go ahead and seal it? Will the colours level out on their own over time with oxidation?

Thank you for creating this great website and community, which is such a valuable resource.

You did not fully remove all the gray oxidation. You could go over it one more time with cleaning if you like, or you could sand it all. Staining it as it looks now should work, but you will have some color variation when it dries.

 

]]> Deck Cleaning Questions and Answers Scott Paul ~ Restoring Wood & Decks Since 1993 https://forum.deckstainhelp.com/deck-cleaning-questions-and-answers/blotchiness-after-pressure-washing/#post-14888 Blotchiness after pressure washing https://forum.deckstainhelp.com/deck-cleaning-questions-and-answers/blotchiness-after-pressure-washing/#post-14887 Sat, 14 Sep 2024 16:11:02 +0000 Hi,

We have a deck that is 7 years old. Yesterday for the first time ever, I decided to clean it with a pressure washer. Next I plan to seal it before the winter. I live in Canada and our winters are long and we get a lot of snow.

I read other posts on this forum and although it's a bit hard to tell from the other users' photos, if I had to diagnose it I think I pressure-washed too harshly. First-timer here. I think I went too close and didn't feather out.

Part of the deck has become blotchy, i.e. there's the original greyish areas, and now some areas that are yellow.

I've uploaded the photos to my Google Photos account (I keep getting an error when I try to attach photos to this forum post). Photos: https://photos.app.goo.gl/zfns7sJv41Abjpw29

Do I now need to sand it? It's not a large area...only 8' x 5' so I could do it with a handheld sander.

What if I don't sand it and just go ahead and seal it? Will the colours level out on their own over time with oxidation?

Thank you for creating this great website and community, which is such a valuable resource.

]]> Deck Cleaning Questions and Answers pd512 https://forum.deckstainhelp.com/deck-cleaning-questions-and-answers/blotchiness-after-pressure-washing/#post-14887