DECK WASHING THINGS TO KNOW BEFORE YOU BUY

See pictures two and a few. I am now preparing to refinish the deck once more this summer months. See Image four of present-day issue. The blotchy search has considerably dissipated due to weathering from snow/rain (I reside in northern Illinois). What did I do Completely wrong last 12 months? What does one endorse I try this yr? Do I utilize the R