How to Make Common Chimney Repairs | Ask This Old House

foreign so chimney repair today huh right so I actually know the homeowner and this is a great situation because they're going to let us get up there they wanted us to inspect the chimney I like the flat roof easy to work on I was surprised walking in to see the whole thing barricaded off I mean I know safety is important but is this Overkill Overkill at all it's what we need it's OSHA compliant yeah okay the barricade up top is going to allow us not to wear a harness that's nice which lets us move around a little bit better the stairs are going to let us have easy access with equipment material everything we need better safe than sorry better safe than sorry is exactly right oh Mark I do love a flat roof all right and this is why you hire a professional to do this again look at the barricades safety is Paramount okay and here's the subject matter right here this is the subject right here so this chimney any chimney what's a homeowner worried about so water infiltration is always the biggest enemy to any chimney and there are three spots that water can come in top okay in through these joints and sometimes the bricks and the flashing let's start with the top so that uh that little vent thing there tells us that this is not wood burning this is for some mechanical equipment in the basement exactly this is a vent and it comes with a metal flange now if you look at the chimney behind us over there Kevin yeah you'll see that cap is made of concrete now I don't want to do that here because this metal and this brick is not really compatible during the freeze thaw situation so what we're going to do is take this flange which does have a bevel so the water is going to shed and we're going to use Caulking and place it and glue it down to the brick so you like this application what's being used using the way it's installed I do the caulking allows for the flexibility as I look at that one over there yes what don't you like about that what I don't like about that is the way they fastened everything so you're going to put screws in each corner of that cap that's going to go into the concrete there's going to be a hole there that's where the water is going to get in and eventually turn to ice and break up gotcha so you don't like the mechanical Fastener you like the flexible one in the adhesive caulk exactly okay so that stays here on the face here on the face you can see these brick brick to Brick the mortar joint is broken that's why we're going to want to grind out this chimney in its entirety so this joint will come this joint will come and all the way through the chimney that's going to help us in two ways it's going to help us get all these cracks and make them solid but it's also going to give us uniformity so I understand completely why you'd want to fix that but this looks pretty good to me I mean it just turns your point of if you only did a little bit now and then a little bit later you'd be paying for the scaffolding twice exactly so that's the most important part once you're up here this is not a ton of work yeah but putting all these barricades up putting the stairs in the staging and getting the staging up that's very expensive when you drag your finger across some of this I saw some of this aggregate fall out right does that tell you so that tells me this is the original mortar and it's very aged when we use our jointer we call it a slick that's yeah that seals that mortar right here you can see all this exposed aggregate that means means the weather has hit it for years and years and years the Slick is gone the Slick is gone and now this joint actually acts as a sponge so it's taking the water in itself okay more water so moving down to our flashing your thoughts right so this is a rubber roof and as you see they've taken the Rubber and they've brought it eight to ten inches up onto the brickwork which is the way we want it they've affixed it properly so I don't see anything that's broken I don't see anything that could be a potential leak so we're going to leave this in place okay so it's really water is the thing that's going to tip off a homeowner to the fact that they've got a problem right that and a bad draft so if the fireplace isn't working properly and they have a downdraft all you have to do is come outside look around all these trees may be a factor in causing a downdraft this hill behind us is also suspect how's that work the hill so when the wind comes off a big hill like that it wants to beat down and as so it'll hit the top of the chimney and beat down and cause a bad draft so how high should it be and is this higher than a normal or yeah so code is about two feet but I suspect when they were building this chimney about 100 years ago they felt that downdraft on their back really and instead of staying with code which was two feet they picked it up another couple feet and that enhanced the draft that's pretty cool all right so top is good bottom is good you want to chase the middle right all right let's repoint let's get going [Music] to inspect up here Mark when we're right up next to it but if you're a homeowner you don't have staging can you inspect it from the ground and how frequently should we be checking our chimney so what you should know is you have a 50-year product house is older than 50 years say 75 or so send someone up to give it a good inspection exactly if you're buying the house the home inspector he'll probably touch on the chimney one of his first things especially given the age of the house but uh definitely get someone on the roof because you're not going to see what you and I have seen from the ground so you gave me a four inch grinder right here yep that's hooked up to our hepovac which is going to collect the dust what you're going to want to do is keep that nose down into the joint because that's where the hose is that's what picks up the dust okay so that goes to the face of the mortar exactly all right so you want me to start with the grinder you're going to go this way you're going to go horizontal you're going to give me a good feel to start with and then I'm going to follow you up with a chisel and I'm going to do all the verticals with a chisel and the reason for that Kevin that four inch blade it may override onto that this brick on the bottom or it may override to that brick on the top but either one we don't want to touch what you're saying is you don't trust me no I trust you I do not let's get the gear on and do it [Music] [Music] [Applause] foreign [Music] why don't you get the water in the brush and we'll start cleaning out these joints once you brush the wetness on it absorbs and therefore it will not take the water out of our mix now we're ready to fill the joints my mortar is always going to be an oatmeal-ish consistency is what I like to say and we're always going to use a Type n Taipan allows for a brick to move a little bit and the weather that we have up here so that's a flexible type very flexible and again we're gonna notice that the joints that we have are a little thicker that's going to make the tool that we're going to use a little bit thicker yep and you call that a this is just a regular margin trowel pointer yep and right there I'm going to start out always doing my verticals first so you know I'm going to have you do all the vertical yeah because that little flip and scoop thing that you do yeah I don't do well that's taken me a long time to perfect but one of the things you do want to make sure you do with any tool is make sure you push that mortar back until you have contact with the existing mortar yeah that way we'll know that it's full and that's very important again why because of water infiltration okay foreign so this is the last head joint for this side now what I'm gonna do is just show you how I want the uh bed joint done and again it's the same thing just make sure you push all the way to the back so we have full joints yep again everything is about water and filtration okay all right and this is how easy it is to attach it possibly go wrong because we scoop it off there like you got 40 years of experience ah I may all right Kevin so you're gonna stay here do these horizontal joints I want to jump on the other side and continue the verticals right there you can use that I'm going to use this I got another bucket here if you want to take yours [Music] so Mark in terms of prevention to prevent this sort of deterioration from happening anything you can do on the inside of the house to stop this nothing really Kevin this is a chimney that's again a hole in your roof so it's out in the elements Mother Nature is going to do what she's going to do so just do your due diligence pay attention to it and act accordingly foreign don't look too close all right well great job but we do have a couple more steps Kevin first we're going to come back in a few days and we're going to wash this with a nice masonry detergent after that we're going to let it dry and then I'm going to use the sprayer yeah I'm going to put waterproofing agent in it and then I'm going to spray this whole chimney down one thing I'm going to do is I'm going to start from the bottom up people sometimes want to go from the top down but if I did that I'd end up with some streaking all the way down there so I want to start from the bottom that way I'll be wet on wet and not wet on dry and you're a big fan of the waterproofer you bring it up a lot yeah huge fan of the waterproofing number one it's going to protect our investment so all right well I learned a lot and I know homeowners have learned some too they know what to look for but they also know what to ask they're Mesa to make sure they're getting a good job so exactly good day all right thanks for your help Kevin my pleasure thanks for watching this old house has got a video for just about every Home Improvement project so be sure to check out the others and if you'd like to see click on the Subscribe button to 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Channel: This Old House

Views: 131,217

Keywords: This Old House, Home Improvement, DIY, Construction, Ask This Old House, Building, chimneys, masonry, Mark McCullough, Kevin O'Connor

Id: 69sGhNMzDbw

Length: 10min 19sec (619 seconds)

Published: Sun Oct 23 2022