Thought I was being gentle, but still managed to rough up a few shingles.
That’s the risk, especially with older asphalt. I tried a pressure washer once—never again. Did you notice any warranty issues after using cleaners? Some manufacturers are picky about what you put on the roof.
I tried a pressure washer once—never again.
Same here. I figured renting a pressure washer would save me money, but it just tore up the edges of a few shingles and made a mess. My roof’s about 18 years old, so I probably should’ve known better. I checked the warranty after, and turns out using harsh cleaners or pressure washers can void it—wish I’d read the fine print first. Now I just use a garden sprayer with diluted cleaner and a soft brush, working in small sections. Takes longer, but at least I’m not risking more damage.
That’s pretty much what I do now too—slow and steady with the sprayer and brush. I’ve got a couple rental properties, and honestly, the pressure washer just isn’t worth the risk, especially on older shingles. Have you ever tried any of those “no scrub” roof cleaners? I’m always skeptical about whether they actually work or just make things look better for a few weeks.
I hear you on the pressure washer—on old asphalt shingles, it’s just asking for trouble. I’ve seen some guys blast away granules without even realizing it, and then you’re looking at a much bigger headache down the line.
About those “no scrub” cleaners... I get where you’re coming from with the skepticism.
In my experience, most of them are more about curb appeal than real cleaning. They’ll knock off the surface gunk and make everything look fresher for a bit, but the moss or algae tends to creep back sooner than you’d hope—especially in humid spots.“I’m always skeptical about whether they actually work or just make things look better for a few weeks.”
Honestly, slow and steady with a brush and gentle cleaner is still the safest bet for old roofs. It’s not glamorous, but at least you know you’re not doing any hidden damage. Plus, you actually see what’s going on up there, which can help you spot early signs of trouble. I wouldn’t trust anything that promises “no effort” results on something as finicky as roof shingles. If it sounds too easy, it probably is.
I get where you’re coming from on the “no scrub” stuff. I’ve tried a couple of those spray-and-leave products on my own roof, and honestly, they did make things look a little better for a month or two. But like you said, the moss and algae just came right back. It’s kind of like sweeping dirt under the rug—looks fine until you actually check under there.
“If it sounds too easy, it probably is.”
That really sums it up. I’ve had the best luck with a soft brush and a diluted cleaner, just working in small sections. It’s not fast, but at least I know I’m not taking years off my shingles. My place is in the Pacific Northwest, so moss is a constant battle. The only thing that’s really helped long-term is keeping the roof clear of debris and trimming back overhanging branches to let more sun hit the roof. Not a quick fix, but it slows down the green stuff.
I do get why people want to avoid climbing up there, though. If you’re not comfortable with heights or your roof is steep, sometimes it’s just safer to hire someone. But if you’re handy and careful, DIY can be totally doable—and you get a good look at what’s going on up there. I’ve caught a couple of cracked shingles and a loose flashing that way, which saved me bigger repairs down the line.
Anyway, you’re not alone in being skeptical about shortcuts. Sometimes the old-fashioned way is just less risky, especially with older roofs. Good luck if you decide to tackle it yourself—just take your time and don’t rush it.
