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Our house is about 22 years old. When it was built, the top of the brick chimney (approx 18″ x 34″ with a single 10″ square flue in the center) was finished by applying a layer of “mortar” about 1/2″ thick. This mortar is starting to fall apart. Will I be ok just removing the old mortar and applying another fresh layer, or should I consider laying slate or some other material on the top of the chimney. If I decide to use mortar, will Quickcrete Mortar mix be acceptable ?
Thanks for any suggestions,
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Just what I need to do on mine....
I'll be lurking for any replies to this thread.
*If it lasted 22 years with what sounds like ordinary mortar, I would take off the existing and re-do it.Use a 3:1 mix of sharp (plasterers) sand with portland cement and a plasticiser. Minimum thickness 3/8" and sloped from the centre to the edges to shed water.Damp down the brickwork before you start to kill the suction a little so the mortar doesn't dry too fast and crack.Cover it with polythene when done for a day or so, again so it doesn't dry too fast and crack.If you want to get fancy, you can tile it with a good quality clay floor tile -- don't forget to slope it to shed water.You could cast a concrete cap for the chimney, say 3" in the centre to 2" at the edges. Cast it in two pieces on the ground and bed it with 4:1 sand/cement.You could certainly use slate -- or granite, if you prefer.
*"sloped from the centre to the edges to shed water"Better/best to clamp some 2x around the top and have the cap project over the edge so that water doesn't work it's way into the crack between the cap and the brick.Leasve room for expansion around the flue liner(s) and seal them well when done.FWIW, I look at 200-300 concrete/mortar chimney caps a year and only see 1 or 2 a year that are properly done and don't have cracks. (In NW Ohio)I i mighthave a digital photo to post; gotta chack another machine.
*Bob, Good idea about the overhang. I am just trying to fix up a few things around the house in anticipation of selling and this is a project I have been putting off for several years.
*Knowing that the odds of any buyer or his inspector atually getting up there to see that are slim to none tells me that you are a damn good man. I'll buy from you .
*"odds of any buyer or his inspector atually getting up there to see that are slim to none"Well, they !
*why not do it right and have your HVAC contractor make a metal cap to go over the existing chimney? mortar, grout, or for that matter any cement based product will crack and no longer shed water, sometimes it will take weeks, sometimes years, but it will happen. Just contact a duct fabricator and they will know exactly what you are talking about and be able to take care of you.
*Hey Bob, would you really go up there? I've got the same situation, takes a 40' ladder at a rakish angle. The top section of flu liner is shakey. I was thinkng of chipping out enough around the liner so I could get in a good bead of silicone caulk, then stucco on top that high enough to shed water. Right now it's a bird bath, what happens when you hire a booby(and we thought they were extinct!). Any suggestions on what to do with the joint between the top flu liner and the one under it?BB
*I don't know what that cross is in the picture, and I think a cap would look like crap in this situation, even though I know it's probably the best solution.
*If that's standing seam, I think I'll pass, thanks.I try to walk every roof, but I've got to be convinced I'll be deciding where and when I'll come downOTOH, if it was shingled, I could probably make it.
*Bob, it's 5 vee, 12/12, you can get a toe hold on the screw heads... so you see why I held a retainage out on the mason?Oh, by the way, you'd be coming down as soon as you got off the ladder, where do you want me to put the mattress?
*"where do you want me to put the mattress? "Close to any of the ladies drifing over from the cooking forum Of course, Ron seems to be hogging the action there! (Or dreams of it.)
*We did an article on forming and pouring a new chimney top in issue 117, June/July 98, pp. 76-79. When I built my fireplace and chimney, I capped it as the article detailed except that I made my cap a couple of inches thick, more than the article discusses. Hauling a couple of hundred pounds of concrete 30 ft. into the air is no fun, but I'm sure that this cap will outlive me.Andy
*You ain't a kidding Andy. And be you like me had no help like when we laid up the chimney. Shoulda done it on the weekend. Did you form in a drip groove on the bottom? Did you by any chance isolate the clay flue from the cap and caulk?
*I had help, in the form of tall scaffold, a pulley, and 100 ft. of rope tied to my truck bumper. That's when my good friend Mark wasn't there, or my wife.I isolated the flues from the cap by wrapping them with closed-cell foam sill seal. Once the concrete set up, I dug a little of the foam out and caulked. Andy
*Thanks Andy. Good friends are worth a million. I'm sure you paid back the favor.
*That's the thing, Cal. I've never had the opportunity. Mark never seems to need anything, but he keeps coming around. He's an honorary uncle to my kids and the best friend a guy could have. One of these days, I'm afraid that he's going to decide to build a house. I'll have to quit my job and build it for him to pay back all the time he's spent on my projects. Andy
*Andy, If he's Italian, you bet he's got an idea in the future. Myself, I've got just a little in my blood. Just enough to remember every favor owed and due. Never waste them and always repay them. Your time will come.
*Nope, German and Polish. Still, I'm hoping he remembers. Favors are valuable, and I'm usually pretty good at keeping the ledger balanced. Did you ever notice there's some people who just don't get that? They're usually kinda lonely.Andy
*You bet your dupa I know what you're talking about. And it's not just the "you gave me an hour, now I owe you one". It's more of an honor thing. You were so gracious to do me a favor that I can't ever not do one for you. It is how us people of class show our appreciation. Some, as you have pointed out, will never get it. And lonely they'll be on the side of the road as the cars zip by. There's all sorts of cliche's that describe exactly that. Pity the poor bastards.Hope you folks had a great holiday.
*This might a be a little to late but... The Masonry book by Black and Decker has a detailed instructions on how to make a chimney cap. According to the book, the form is built around the flue with 1/2 inch plywood After the concrete is cured, it is removed. Since the form is around the flue, once you remove it, you have your 1/2 inch gap which you caulk with 'fireplace' caulk.There are also 'paint type' products that you can use to seal the cracks and cover the cap. Think of it as something like a driveway crack filler and sealer for a chimney cap. I do not know the longevity or sucess of these products. A while ago I posted a thread asking for information about these type of products. Specifically ChimneySaver but I received very few replies, actually I think none.
*whats the best material to use for waterproofing the chimney brick and motar?
*
Our house is about 22 years old. When it was built, the top of the brick chimney (approx 18" x 34" with a single 10" square flue in the center) was finished by applying a layer of "mortar" about 1/2" thick. This mortar is starting to fall apart. Will I be ok just removing the old mortar and applying another fresh layer, or should I consider laying slate or some other material on the top of the chimney. If I decide to use mortar, will Quickcrete Mortar mix be acceptable ?
Thanks for any suggestions,