Dirt Stains on Cedar Deck


New Member
I'm back now with my latest adventures.

We put gardens around the deck, and some of the top soil sat on the deck for a couple days. Little did I know this would stain the deck. Deck is cedar with Wolman F&P on it. (stained 1.5 months ago)

I tried using water to clean it with a brush. Didn't work.
Then used a very dilute (2oz/gallon) Sodium Percarbonate/Warm water mix. Didn't work.
Upped the mix to 4oz/gallon and it seemed to work better, BUT when brushing, the surface started to "pill" up. Then when I hosed it down, the wood in the areas I brushed seems stripped of the stain. I splashed some water on it, and it beads up, but not as well as the parts un-brushed. Its clearly lighter than the other un-brushed areas too.

Did I just strip the protection from my deck?

If so, do I need to do the whole deck, or can I spot treat without seeing lapmarks?

Also, in the future, how best to clean a deck.

Thanks. Go easy on...I know I screwed up.


Welcome back Greg!

You stripped some or all of the surface sealer off, which offers the uv protection and it keeps the oil from drying longer. Your wood is still protected from moisture damage, but those spots will dry and age faster than the rest if left untreated.
You can feather in some f&p to patch it. Brush it with the grain. Thinner is better, since the wood still has good oil saturation. You will likely be able to see the spots for at least 2 weeks, but it'll blend as it fades.

For future reference, I've had best success with stripper on F&P vs percarb. You might find a TSP (Trisodium Phosphate) over the counter stripper that'll work, but nothing beats a mild Sodium Hydroxide solution on F&P.

Also for future reference for cleaning dirt off the deck: If you're up for scrubbing it by hand, use warm tap water and the softest scrub brush you can find.

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