Hey guys,
I’m looking to clean this deck here and it’s very large.
I’ve done a lot of decks before but the planks on this one are quite a bit wider than any I’ve done and I can’t cover a single plank with any of my fan tip nozzles (I don’t want to leave any marks from overlaps with the pressure washing)
Should I apply SH or Oxalic acid on there or do a pressured washed of it carefully?
Usually use sodium metasilicate or sodium precarbonate, sometimes sodium hypochlorite… always oxalic afterwards. Pressure around 900-1200 depending on wood. You can always move the wand further away to cover the whole board and also lower the pressure.
SM would be best. Per carbonate works. SH works. Always Ox when finished.
And you won’t leave wand marks if you can’t cover the whole board. Wand marks come from starting/stopping without first fanning out the wand.
What type of wood is that? The pressure treated pine lumber around here would shrink and cause considerable gaps before ever reaching that level of gray.
Looks like some type of hard wood?
Awesome thanks - I’ll give that a go
You clean this deck different than normal PT pine deck since its hardwood. The other commenters haven’t described the process right. If you follow their advice you may very well clean it but the results will be sub-optimal. All you need for the first step which is the deep clean is a little bit of sodium hydroxide and surfactant and spray that on (about 4oz/gallon is plenty with the NaOH) and agitate the outer layer with a medium stiff bristle brush. Then go over each board with around 1500 PSI with a white tip (whatever size that is for your machine). Work in sections, I like to take about 50 square feet at a time but if its hot/sunny then less. If you do notice any presence of organics here then adding sodium hypochlorite in this first step to the mix is completely acceptable. Then make an acid solution (I like a mix of citric and oxalic) around 8oz/gallon of the mix and spray on and then rinse off with low PSI.
That looks like an exotic hardwood like Ipe or Cumaru. Dont treat it like PT pine. Take an hour and look into the different methods. Please don’t bleach out someone’s expensive deck. It deserves to be treated well. I have done a couple and they look amazing after cleaning and oiling.
