I have been seeing a nearly Ph neutral product called Wet and Forget that you can just spray on and let it do its stuff. No rinsing, you can leave it on roofs.

Anyone used it or something else like it that you liked?

I am getting a bit of green gunk on the north side of my roof that is shaded, and on shaded spots on my cultured stone on the deck.

Costco sells Wet and Forget this time of year. Or at least they have in the past.

I bought it a few years ago to use up in Door County (house in the middle of a cedar forest, so mucho shade and moss) but never got around to applying it.

I thought about bringing it back down here to use on a shady area of my backyard patio when the house up there sold, but as I recall there were some cautions regarding pets so I decided to skip it.

I've never heard of it, and wonder if it works. We have a lot of deck that needs annual pressure washing here in the ol' PNW. Plus this winter was warmer than I recall (I think we only had a few days of subfreezing/snow), and our algae in the shady areas is, um, impressive.

We had bad moss growth on the roof at our old house. When we re-roofed, the roofers put a strip of zinc tucked under the top row of shingles. It stuck out about an inch and you could see the shiny metal for a few weeks til it oxidized -- then it blended in and was basically invisible. But I guess when it rains, the rain washes a bit of zinc down over the roof and that kills the algae. We lived there for several more years and never had any algae growth so I was impressed. They did say the zinc strips were something that could be retrofitted onto an existing roof (our roof was just shot and needed replaced anyhow). Anyhow, the nice thing about it is it's once and done - no need to treat and retreat.

quote:

They did say the zinc strips were something that could be retrofitted onto an existing roof

Yep, we had one put on our roof here prior to closing (the inspector recommended it). The roof still looks good, no growth.

We had the zinc strips installed in the WI house when it needed re-roofing ten years ago. They work quite well.

But that doesn't help you with siding, concrete, bricks, or wooden decks.

We had some concrete on the north side of the house (front porch and garage apron). I couldn't even get the moss off of the front porch with a power washer. It was an electric model, which might not be as powerful as a gas unit, but still....

Costco still sells Wet&Forget. Might check out the reviews.

https://www.costco.com/wet-%25...oduct.100338171.html

Interesting.

Can happy homeowner install a zinc strip somehow?

Cost?