Roof chimney base and flue repair

Discussion in 'Roofing and Siding' started by rpinero, May 25, 2019.

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  1. May 25, 2019 #1

    rpinero

    rpinero

    rpinero

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    20190522_181015.jpg 20190522_181022.jpg 20190522_181211.jpg I am a little unsure where to start with this problem. A tree fell and damaged my metal chimney flue. I am not even sure what it is called and am having a hard time searching online for a replacement if i need it. It's not a brick chimney on top or the house but a metal one. It's dented from the impact of the tree and the base took some damage and cause water to get in. I'm confident enough to remove and replace shingles around the base after i add flashing but am wondering if the whole thing should just be replaced. if so with what cheaper alternatives? This is my first time attempting any roof repairs but i've done a lot of housework and am pretty confident with some advice i can get the job done.
     
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  2. May 25, 2019 #2

    Snoonyb

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    The top portion is generally refered to as a spark arrestor and is separate, in that a variety of designs are available.

    Removing that piece will tell you if the stack is single, double or triple wall. The critical dimension is that the chimney must extend above the roof, 24" within 10' of the chimney stack.

    If you are confident that the roof flashings are intact and will not allow water intrusion, then leave them be.

    However if you have question about their viability, then 1st build a cricket on the upslope side of the chimney and do it correctly.
     
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  3. May 25, 2019 #3

    rpinero

    rpinero

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    Thanks for the advice! I dont think i can easily remove that top part as the body is dented in also. I suppose i may have to replace the entire thing to be safe. What should i look for to replace it without bricks? is there an easy alternative? Im looking into chimney pipe accessry kits as they have a flat flashing base. is that a good start?
     
  4. May 25, 2019 #4

    oldognewtrick

    oldognewtrick

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    You should be able to remove the chimney chase, that's the square flat metal, and the top. Your pipe inside should have a flashing collar at the roof deck. The collars and spark arester can be purchased from most plumbing supply houses. At least that's where I've found them here in middle TN.
     
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  5. May 25, 2019 #5

    Snoonyb

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    Were it I, I would attack it with a hammer, pry bar and tin snips, and try to expose the fasteners to remove the spark arrestor, when that is removed I'd attempt to reshape the stack using a hammer and duckbill hand break, to as close to the original rectangular shape it was, purchase and install a new spark arrestor.

    You'll find that the new spark arrestor will have the required hardware cloth mesh.

    If instead, you elect to remove the existing then I would go to a sheetmetal shop and get a quote, when you know what you need.
     
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  6. May 25, 2019 #6

    rpinero

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    Maybe i can cut it with my dremel and get it down to where it is all good if the inner pipe is good and allows? If not and i can manage to replace the cap, should a little roof patch around the edges be enough to seal up the edges? The impact definitely dislodged the chase from the shingles around it. I only visited the chimney once but its possible there's more damage than i expect once i do investigate it thoroughly. I'm trying to gather as much info as i can before i go back up there to get to work on it.

    worst case would it work without a chase around the pipe exposed like this picture? upload_2019-5-25_17-9-11.png
     
  7. May 26, 2019 #7

    Snoonyb

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    You need to understand what you have there.

    Because it is easier to flash a square or a rectangle, the casing is just sheetmetal from the roof up with a flashing at the base. With it removed you have a round metal chimney, similar to that pictured, that could be 8", 10" or 12" and is a min. of double wall and likely triple wall, which have specific Amer-i-vent fittings which are intended to be replaced, in kind, and are illegal to be cut and other pipe melded to it.

    Back to my previous comments regarding the viability of the flashing.

    You can cut the chase with a tinsnips a lot faster than with a Dremel, the have a sheetmetal piece formed the sane size as the chase, and with a hand crimper, crimp the existing and fit the new piece over and attach with tech screws , or #8 A points, no waterproofing needed.
     
  8. May 26, 2019 #8

    mabloodhound

    mabloodhound

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    Yes, the picture you show will work fine. The base will have all the metal flashing attached and you will shingle over that up to the pipe.
     

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