A long time ago I had a large deck built on the back of our house, and my builder encouraged me to construct it from treated wood and never stain it, and to just allow it to weather naturally.
It actually looks quite good, as the treatment on the wood turns it a slight green colour, that does fade in time, and gives a nice natural, weathered look that seems to fit with the rustic decor I like to maintain in the backyard. I like the look of weathered wood, from bird feeders to the grandkid’s Winchester Playhouse.
However, over time, even a weathered deck gets to be a bit grungy looking, and requires some cleaning & maintenance. The biggest culprit we have is a black mildew forming, especially under the pagoda that my wife has her hanging baskets gracing. These baskets need daily watering in our summers, and invariably they get over watered and drip the excess onto the deck, and before you know it you have a big black mildew patch forming.
I normally just scrub these patches with a stiff broom and some liquid deck cleaners, but last spring, after I’d decided to rent a gasoline power washer, I decided just pressure washing would be a lot simpler.
Now, I’ve had lots of experience with one of those puny little electric washers, where you have to keep the wand about an inch or two away from the surface you’re cleaning, (or else you may as well just get a broom out, as it’ll be just as effective).
However, I rented a pretty powerful gasoline powered power washer, in fact it was almost a commercial model, and could this baby ever blast stuff.
I’d rented it for the weekend, so why not get value out of it I thought? So the deck got a “once in five years” power washing. The trouble was I’d not been used to the incredible pressure that a decent washer produced, and I proceeded to blast away the mildew from a distance of my normal 1-2 inches. Sure did get rid of the mildew!
Trouble was, when the deck dried it revealed that the pressure of the washer, from such a close proximity, had also penetrated the surface of the deck, and torn the fibers of the wood. What had been a nice, smooth, aged wooden deck surface, was now an uneven mess of soft, raised fibres, that were not only unsightly, but also a bit dangerous to little bare feet of the grand kids.
Luckily it was a rectifiable situation, but it did require being on hands and knees with a sander for a few hours.
Lesson learned; know your equipment capabilities and use accordingly!