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How to Fix a Bulging Chimney

  • Transcript

    LESLIE: Coming up next, we’re taking a call from Carrie in Minnesota who has a cracking wall.

    Carrie, tell us, where is this crack occurring?

    CARRIE: Hi. Oh, my crack is along the chimney. I don’t know if you’ve ever seen where they put a faceplate; looks almost like a paper plate.

    TOM: Yes.

    CARRIE: The plate has actually moved. It’s bulged so much that the plate has moved down. You can see the cracks on the top.

    TOM: Sounds to me like you have a very old house. Is that true?

    CARRIE: It was built in 1941.

    TOM: OK.

    CARRIE: So it’s old but not it’s not old, ancient. We have checked it out. We’ve had our roof redone. The construction people said that our chimney was sound. It was not damp at all inside. So as near as we can tell, there is no water. We have no idea why it’s bulging like this.

    TOM: Now this is the area right around the chimney where the chimney is inside the wall or is the chimney standing outside the wall and you can see the bulge?

    CARRIE: This chimney is inside the wall.

    TOM: So what it sounds like is happening here is you have two dissimilar materials. You have the construction of a masonry chimney, probably a brick chimney, and then you have a wood wall up to either side of it. And so you have, just built into that, two different types of framing material that are going to move at different rates and at different speeds. Now also, the masonry chimney where it pierces the roof, how tall is it? Is it a fairly tall chimney?

    CARRIE: It’s two stories.

    TOM: What often happens is chimneys will – the mortar will actually dry out more on one side of a chimney than the other and that can cause the chimney to bulge slightly as well. Generally, it’s not something to worry about but if you’ve seen this go on over years, I could see why it would be upsetting to you.

    What you need to do is to break out the old bulged plaster and basically rebuild that section of the wall. And the best way to do that is with a plaster of Paris mix, as opposed to using spackle, because plaster is actually going to harden quicker than the spackle would and it’s an easier and more workable surface.

    CARRIE: You wouldn’t recommend taking and gutting it and pulling all the plaster off?

    TOM: Well, you could take that but I will tell you there’s no such thing as a short, neat plaster removal job. If you’re dealing with just one area that’s bulged, you could repair that a lot easier than tearing the whole thing down. Before you tear it all down, though, another option is simply to skin it – to go on top of it with drywall – but I’m not so sure that that’s going to solve your problem because you’re more concerned about the difference in the bulge. And to do that, that means that you might have to actually take the wall down, take it apart, and shim it up until it’s nice and straight.

    CARRIE: Oh, boy. OK. Yeah, because I mean it’s a – well, it’s a curve when you put it on there. I mean it almost – you know, it’s like a flattened-out basketball times – I mean it’s very prominent where people have actually commented when they come in like, “Is your wall going to fall down?”

    TOM: Well, tell them it’s personality. (chuckles)

    CARRIE: (chuckles) Yeah, it has personality.

    TOM: It’s charm. Well, why don’t you head down to The Home Depot – there’s one near you in Willmar – and pick up some plaster of Paris, break out that old stuff, and then very easily and very gently refill that loose, bulged area until you get a nice, flat surface there. Sand it, prime it, paint it, hang a picture on and you’re good to go.

    LESLIE: And in fact, they have a patching plaster set that you can get which has everything need to repair the surface cracks and it’s in a 4.5-pound box.

    CARRIE: Alright. Well, thanks so much you guys. This was just something new and it’s been happening over the last two, three years and it’s becoming a source of concern.

    TOM: Well, hopefully we’ve shown you that there’s not much to worry about and what you’re looking at is just a little bit of good, old-fashioned charm.

    CARRIE: (chuckles) Alright.

    LESLIE: That’s one way to look at it, Tom.

    TOM: (chuckles) You’ve got to be an optimist, Leslie. Come on. (both chuckle) Thanks so much for calling us at 1-888-MONEY-PIT, 888-666-3974.

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