How to Clean and Prevent a Mossy Roof | Ask This Old House

[Music] Ryan hey Tom glad you're here nice to be here appreciate it he wrote me about your roof yes we've got some moss on the roof we'd love to have you check it out all right let's take a look yeah I can see the trees that usually a sign anyway we get shade you're gonna have moss and you've got moss they see that yeah we got it we got a fair bit of it yeah you know the best thing is to try to get sunlight on the roof you could cut down some trees but don't really want to do that we'd love to keep them and they're also they're our neighbors trees yeah well cutting down the trees on this side here is still not gonna be enough okay because the Sun is coming from the other side of the house this little bit of shade that the Sun doesn't get will still grow moss it might not be as bad but it's still gonna get why all right what can we do about it well you we first of all we have to take it off the reason we have to take it off is because it's gonna shorten the lifetime of your roof that moss holds moisture when it gets wet longer doesn't the shingle won't dry out so the shingle gets saturated that moisture is then transferred to the sheathing and it could rot the sheet okay I don't want that no you don't want that so we got to get it off let's get rid of it okay all right Brian working on a roof is dangerous so we have our harnesses we have our line our fall protection and a bracket that I've screwed to the rafter so that we don't fall okay great okay now the first thing we want to do is we want to lightly sweep off the roof and remove some of the moss it's on which ever use a power washer to get this off well as a homeowner I would say no because number one I wouldn't want a homeowner up on a roof that's wet right with a power washer and you could also damage the roof shingle if the power washer is too strong okay and that's why I said to you we want to sweep it lightly yeah got it all right if we don't get all of it we're really he's going after the big pieces and kind of a loose piece all right we'll remove most of the moss that was on the roof I swept it clean to get rid of the debris there's still another step that we have to do but before we do that I want to install this metal strip right here across the top of the roof what does that do this is actually a zinc strip and what the zinc does is it'll be exposed so when the rainwater hits it the rainwater will take the particular it's out of the metal it will run down the roof it will kill off the moss the legend and the mold really that works that works and so will copper or lead great all right so now you watch out for the edges because I don't want you to cut yourself get it started right here and let me get one nail in here we go too far all right we're just going to use a black roof spent to seal the nailhead great you do that and then what I'm gonna do I'm gonna also drive it home and you're gonna put another one on top of it right the reason we're face nailing this and sealing the nail is because we're nailing through the flange and I'm keeping it up high to the ridge vent normally we could keep it down one or two rows okay and that would slide up underneath the shingle and then the shingle would hide the nail but your roof has so much moss up under that ridge vent I felt it better to put it tight to the ridge vent all right now we're just gonna wet down the roof with these pump up sprays and we've mixed about a third of a gallon of bleach to a gallon and a half of water okay and I had you wet down the grass of the plants down the blow so if any bleach spills down there it won't kill the plant right how long will it take to kill all this oh it's probably going to take a few days and before you know it you won't have any moss all right Brian it's always good to wash down the plants before and after especially after so if we went away any of the residue bleach that you come down you won't kill your plants great now it's probably gonna take a few days for that Moss to start dying then a good rainstorm will rinse it away and this be good as new great and that zinc's gonna keep it from coming back right it's a bow still fantastic thanks so much my pleasure all right guys nice job Tommy and he seemed like he was a good helper he was a great helper and he wasn't afraid of heights it's just not always the case when it comes to homeowner that's right if I say if you're a homeowner and you're afraid of heights hire professional do not get up there but if you are willing to get up there it's about safety you guys had your harnesses on right it was great we've seen you wear a couple different kinds the one you had on in that piece we rope rope in the lanyard this is a little break here right that's right but you've also worn something like this in the past yeah much bigger and it's like a seat belt right yeah that's a retractable and it has a lanyard right here but it actually senses a sudden jerk yeah see it'll grab so if I started to fall quickly it would it would stop me this is a lot more compact than that you have a preference yeah I prefer the Rope as much of a pain it is but you have to make sure the Rope stays out of the way so you don't trip on it because if you wear this and it's attached to you all day long this is pulling on you and it's always trying to pull you back up to the roof it's a bit of a pain I thought you were a pain all right so if you're going to wear either one of these it all comes down to how you secure to the roof you've got a bracket that you've got to get in and you said go into the rafters you have to go into structure how do you find the rafter you're gonna use your knuckle again there I could use my knuckle and find it very easily but you you I don't know but if you listen I listen by sound and I and I can actually feel the difference so start banging oh yeah the rafter right there so if I continue on oh there's a rafter there all right so the idea of it is you can go to the home center and you can buy a starter kit like this and in that cart start a kid it gives you pretty much everything you need from the harness to the bracket that you mount on the roof the screw and the rope okay all right so this goes on a ridge there's different types this one goes over a ridge you find the rafter you place it over then you put six screws on this side six screws on that side and you attach your bracket to great you survive the day you don't fall off roof now you got to take that off and you got 12 holes through your roof twelve holes aren't bad you haven't fallen and you haven't got her it but those twelve holes are easily repaired you just take it there's a cockatoo above cocking and it actually has a roofing mastic in it yeah with the tip you force the caulking into the hole and you just smooth it over and that won't leave same stuff that you use to seal the nails when you're hammering in that metal strip exactly awesome good information Tommy thank you thanks for watching this whole house has 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Channel: This Old House

Views: 930,119

Keywords: This Old House, Ask This Old House, DIY, Home Improvement, DIY Ideas, Renovation, Renovation Ideas, How To Fix, How To Install, How To Build, Tom Silva, roof, moss, cleaning, prevention, 7-10 minutes, How to Clean, How to Clean and Prevent, Mossy Roof, Ask This Old House general contractor, tom silva interview, tom silva this old house, tom silva framing, contractor Tom Silva, renovation home, How to Clean mossy roof, How to Clean and prevent mossy roof, mossy roof cleaning

Id: f_jbaGCR6oo

Length: 7min 44sec (464 seconds)

Published: Mon Feb 10 2020