This split level deck had been neglected for a few years and had become slippery and dangerous.
The surface was infested with green algae and it's stain had permeated the underlying timbers. The discolouration was etched into the boards, even after pressure washing.
We used a low-pressure wash, so not to damage the wood, and then applied a strong biocide solution to eliminate the discolouration.
The end result was fantastic.