Removing moss from crevices of a roof

Spencer Claeys specializes in deep cleaning and removing layers of moss from roofs. He starts the cleaning by removing loose debris and brushing the moss. He applies a chemical spray and treatment powder to prevent moss regrowth.

Spencer Claeys: My name is Spencer Claeys, and I specialize in deep cleaning and removing layers of moss off of roofs. The area that you live in and the climate definitely plays a huge factor into the amount of moss that grows on roofs. Up here in the Pacific Northwest, we have a lot of moss because there’s a lot of rain, there’s not a lot of sunlight, and there’s a lot of trees and stuff that provide all that material for the stuff to grow on.

There’s probably hundreds of thousands of species. But generally, if it’s green or black or something living up there, it needs to be removed. So, here, this gutter-guard sponge was completely grown in, compacted with mold, moss.

So we need to get it out, put in some new gutter guards so that the gutters can be flowing and working as they should. The purpose of the gutter guard is to keep stuff out of the gutters. This sponge got so grown in, compacted and stuff, that we needed to remove it and put in new gutter guards.

The moss can get up in between any crack or crevice that you have up on the roof and the gutters. It either grows bigger and bigger and bigger, and then water can get up in there as well, too, or in the winter too, when it freezes, it can freeze and expand, really break that seal that your house or roof typically has. So, moss really loves growing especially on roofs that have a lower pitch.

When it has a higher pitch, it has a harder time grabbing onto a hold of the roof. But if it’s a lower pitch and it’s a lot less steep, there can be quite a bit more moss because it has a lot easier time of getting in between the cracks there. And generally, you’re going to see a lot more moss growth on the northern side, where there’s lack of sunlight.

So that’s really one of the biggest factors. Moss has the easiest time growing in between asphalt-shingle roofs. The moss can really get up in there, grow, expand, and break the seal of the shingle for the roof, and water can get up in there.

More moss, organic material, and it can cause mold, and water can get up in there and damage the roof. I’ll generally start any cleaning process with the leaf blower and the brush, getting all that organic material off before I start treating it. So, when you see this level of moss up on a roof, there’s almost no way around.

You gotta get that moss off there. You gotta brush it off. Because even if you treat it, it’s still, there’s just so much organic material up there that the moss is going to have a really easy time just regrowing.

Once you get rid of it, it’s going to be so much easier to treat the roof, keep it from coming back. I’ll use a stiffer nylon brush. We really want to be careful when we’re brushing.

If you brush too hard, you can definitely damage the shingles. But if you’re doing it the right way, you’re doing it gently, you can just get rid of that moss by just gently kind of flicking it off. You can leaf-blow it off later.

So, every roof is different. It really depends on how established the moss is, how much moss, what type of moss, if there’s a lot of trees. That really affects the amount of pressure that I use when I’m brushing it off.

Here, I’m using a stick because the moss is so grown in that the brush can’t even really get in between the cracks. And I’ll generally alternate between the stick and the brush, depending on the moss level, depending on what gets it off the quickest. I’ll follow the leaf blowing with another hand-brushing, and this will get everything else that the leaf blower didn’t take care of.

It’ll get it loose, and then we can blow it off later. Once all the moss is gone and the roof is clean, we can begin the treatment process. When you’re treating a roof, our main purpose is to raise the alkalinity, so raise the pH.

And you can do that with laundry detergent, you can do that with zinc powder, and also baking soda you could use. Sodium hypochlorite, which is like bleach. And with the treatment, it’s usually a combination of different chemicals that I use that raises the pH and then makes it really hard for the moss to get established and come back in the future.

When you see me spraying up there, that’s usually the sodium hypochlorite, basically bleach, killing everything up there, and then the moss-preventative powder. When I apply the treatment powder up on the roof, I really want to be hitting the peaks really hard, because that’s going to flow down the roof eventually. Ledges, gaps, seams, places around the windows as well.

You want to put a little bit extra sometimes down there. The size of the roof really determines the amount of powder and treatment I’m going to need to put up on the roof. When you put the treatment powder on, you can leave it on there.

You don’t really need to touch it. The rain is going to take care of the rest for you. It’s going to wash down over the next couple weeks.

Most cleanings that I do are roofs that are at least five, 10 years old. Because moss is so damaging, I always recommend homeowners get their roofs cleaned and treated every year to uphold the integrity and longevity of their roof. Read the original article on Insider.