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Hi Bunnings workshop community,
I'm dealing with an old weathered decking, and I'm wondering what's the best way to tackle this problem.
I'm planning to clean and stain the decking, however when trying to use a pressure washer to clean the decking, getting close enough seems to slightly damage the wood, and during washing it reveals a green mossy hue in the wood.
I've had more luck brushing with water, would brushing work here? Or is it too weathered?
I've attached photos below; any help or suggestions would be appreciated. Thanks!
Photo of weathered part of deck:
Part of deck that was under more cover:
Attempts at pressure washing (2nd photo more obviously shows some damage when getting close enough to get black grime off):
Attempt at brushing:
Hi @Bill1990,
Your pressure washing results actually look quite good—there doesn’t appear to be any real damage in the images you’ve shared. What you’re seeing is the surface moss and algae being effectively blasted away, revealing clean, fresh timber underneath. Unless the timber is going furry, splintering, or gouging, I’d say your pressure washer is doing exactly what it should.
If you’re still unsure or want to play it safer, you could try scrubbing with a deck cleaner at full strength—possibly over two applications—to lift the blackened surface buildup. But ultimately, you do need to remove all of that weathered coating and organic material before staining, and the pressure washer seems to be the most effective tool for the job in your case.
Once the deck is clean and dry, you’ll be in a good position to sand back any rough spots and then apply your new stain or oil.
Please let me know if you have any questions.
Mitchell
