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leaking masonry chimney

| Posted in General Discussion on February 27, 1999 06:58am

*
Can anyone help us? We have a new brick masonry chimney which seems to leak through the brick. All necessary flashings are in place and in good condition (leaded copper).Chimney has been sealed with commercial sealants,to no avail and the flue has a cap.During rain the chimney which can be observed in the attic begins to get damp mortar joints then eventually becomes soaking wet as the rain continues.

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  1. Guest_ | Feb 19, 1999 03:14am | #1

    *
    Gregory, I hate to say this...but is it possible you have built this chimney out of the wrong kind of brick?? Not all bricks are suited for outdoor use and can indeed soak up water like a sponge. If this is the case , you may want to try another type of sealer. Also, it may take many coats to do the job. Most sealers will seriously damage normal roof shingle if allowed to come in contact with the shingles. I have found them to be very effective.

    If all of this fails, I'm sure you know the real "fix".......

  2. Keith_Utter | Feb 19, 1999 04:25am | #2

    *
    Gregory, Does the chimney's masonary cap overhang the brick? Is there a sealant against the flue tile where it joins the cap? Aside from the possibility of the wrong brick, these are to places that can leak. Good Luck

  3. Guest_ | Feb 19, 1999 04:33am | #3

    *
    Take a closer look; is there any area that appears wetter than others? Does it get wet first, followed by other areas?

    Take a closer look at your flashing. Try this: on a dry day, get up onto the roof with a garden hose. Using a small stream of water, wet down small areas of masonry. Wait several minutes before moving to new area--give it some time for the water to naturally trickle. Have your partner in the attic report what he/she sees.

    I'll bet you have some flashing not completely watertight. The trick is finding WHERE, exactly.

    1. Guest_ | Feb 19, 1999 08:47pm | #4

      *Gregory,go back to checking the flashing.Wet down the roof with a hose being carefull to keep water of the brick.Start on the roof below the chimney and SLOWLY work uphill.Have someone inside checking while you work the hose .Work uphill about 6" every 4-5 minutes.(it can take a long time to soak through)After you work up to about 24" above the chimney you can probably ignore the shingle/flashing intersection.Next use the same technique to test the flashing/brick intersection.Is flashing properly constructed cap flashing inset in the mortar or is it just nailed to the side of chimney and then caulked ?(congrats on finding a customer who will pay for copper ,I am more than a little envious).Also check the joint between the back pan, the back pans' cap flashing and the sidewalls' step flashing and cap flashing.If you can now eliminate all these areas start working your way up the brick work. Remember you are trying to duplicate the effects of rain,not a firehose.I suspect the problem may eventually prove to be the mortar cap or somehow the chimney cap is letting water run inside the flue ,migrating out through a joint in the tile,across a glob of mortar and cascading down the inside of the brick work.Althogh the problem might be the type of bricks I don't think so because you indicate the water first appears along the mortar joints.PS. I have solved problems like this on hundreds of chimneys but there was one I could never find the cause, a 3 flue chimney with the long side running down hill.It is situations like this that make me envy doctors who can say"I favor a long term treatment approach to this condition" and then eventually bury their mistake. Best wishes and good luck

      1. Guest_ | Feb 20, 1999 04:51am | #5

        *Stephen said what I tried to say, only much better.

  4. Gregory_Baron | Feb 20, 1999 06:16pm | #6

    *
    A good thought but no, I used Glen Gery Brick 52W5 rated SW for severe weather. I have coated the chimney with many coats of sealer. And Yes, I know the real "fix" but my wife (who is typing this response) really doesn't want to go through all of that. The chimney is only 2 years old and was built with a 100 year old style in mind.
    Thanks for your response, if you come up with any other suggestions please advise

    1. Gregory_Baron | Feb 20, 1999 06:18pm | #7

      *The cap overhangs the brick. The concrete wash at the top of the chimney is in excellent condition, no cracks, or shrinkage and I sealed around the flues with GE silicone caulk. Bricks are Glen Gery 52DDSWfor severe weather. Thanks for the reply.

      1. Gregory_Baron | Feb 20, 1999 06:20pm | #8

        *Yes, I have done the water test with hose and sprinker to mimic long term rain. I could not find any evidence of water penetrating the flashing. Thanks for the reply

        1. Gregory_Baron | Feb 20, 1999 06:25pm | #9

          *yes we conducted a water test and it did not reveal that the flashing is leaking. I installed the flashing into the mortar joints. I also have a copper cricket behind the chimney with soldered joints. I also installed a pan through the chimney, which is copper also. I have applied numerous coats of recommended sealant. The joint between the flues and the concrete wash are caulked. Flue caps were installed after the first leaks were detected and did not rememdy the problem. Bricks are Glen Gery 52DD severe weather. PS: the customer is myself! Help

  5. Guest_ | Feb 20, 1999 06:48pm | #10

    *
    Gregory, Sounds like the bricks are OK. Your comment that the mortar joints in the attic get wet and then the whole chimney gets wet tells me that the water (in large quantities) has entered the holes inside the brick and is flowing through them into other areas.

    I now suspect any flashing that projects far enough into the brick to reach the holes. Prime suspect is the saddle behind the chimney which is cut in. Have you used a good caulk at the joint where these flashings penetrate the brick?

    Also, did you by any chance rake the joints? This could cause a path for water into the core holes.

    1. Guest_ | Feb 20, 1999 08:16pm | #11

      *Gregory,It's time for another pair of eyes to look your chimney over. Where I live, my chimney sweep is the local expert with good experience solving leaks like yours. Find out who your local expert is and give him a shot at it.Jack : )

      1. Guest_ | Feb 21, 1999 12:57am | #12

        *ADK Jack has a good Idea.If you find the local expert he may also want to know if it leaks during most rains or just the hardest ones,does blowing rain make a difference and from what direction.The thoght about the holes in the bricks is also good(wish I had thought of that)Some times if the upper courses are corbelled outward and then inward the holes can be partialy exposed on the inwardd return and the mortar cap will drain right into those puppies.Let us know how all this is resolved and good Luck

  6. G.LaLonde | Feb 21, 1999 01:24am | #13

    *
    Stephen, That thought about the upper corbelling is a good one! (Wish I had thought of that)

    1. Gregory_Baron | Feb 21, 1999 04:01am | #14

      *I used GE silicone and I did not rake the joints, they are struck flush.

      1. Gregory_Baron | Feb 21, 1999 04:03am | #15

        *Jack,Where we live it is hard to find someone that we can trust. Also I have spoken to local masonry supply companies for recommendations and have still come up with nothing that works. :)

        1. Gregory_Baron | Feb 21, 1999 04:07am | #16

          *Stephen:We need a rain fall of more than 3 hours to create the leak. Driving rain causing the leak to appear faster, but maybe only by a half an hour time wise. Direction of rain and wind doesn't seem to make a difference. As for the brick, Glen Gery 52DD severe weather is a common red brick with a frog, it is not a core brick. We are hoping for some kind of luck to happen soon :) thanks!

  7. Guest_ | Feb 21, 1999 09:08am | #17

    *
    Gregory,

    What I am saying is you need a pair of eye's to examine your problem in person. It's
    b not going to be solved here
    till Sean gets the
    b FHB loaner "web cam"
    and "rain generator" up and running as well as this site.
    Chimney sweeps charge for there service, and are in the yellow pages, not the masonary supply house.

    You're seeing my point as well as I'm seeing your leak,

    Jack : )

    1. Guest_ | Feb 21, 1999 09:17am | #18

      *Silicone!...That could very well beb not bondedto the brick and or mortor.Try removing some of it and see if it is...Capillary action is real amazing too...thousands of gallons of water flow up the tiniest of tubes in trees(slice off 1/16" end grain piece of oak, hold over your eye, and "see" for yourself) against the pull of gravity in huge Western Fir trees...How tall are they? hundreds of feet?Hate to be raining on anyone's parade,Jack : )

  8. Gregory_Baron | Feb 21, 1999 07:53pm | #19

    *
    Great Idea, but how about a solution. I've checked and the silicone is well adhered.
    Gregory

    1. Gregory_Baron | Feb 21, 1999 07:56pm | #20

      *OK wise guy, I think I will try the camera idea! A friend of mine in the plumbing business has a camera for inspecting sewer lines and maybe I'll give that a try. You never know what it might reveal.Maybe your "point" just might lead to revealing my leak!Thanks

  9. Guest_ | Feb 21, 1999 10:06pm | #21

    *
    GREG, I hate to ask but is there Ice gaurd under the flashing?Also ,and this is very unlikely but I am curious,is there a valley close by(within 20 feet).I am sorry you are having this problem, but I got to admidt it is kind of fun(in a twisted way)since it is your job and not one of my jobs.As always,Good Luck,Stephen

    1. Guest_ | Feb 22, 1999 07:40am | #22

      *Gregory,"Stone Walling"...def. - to, if you will, by post or bi-postally create an intricately entangled cyberspace profuse in dis-enlightening detail, a "possession;" as to nearly mimic wholly, or in part, that which ordinarily could only occur in a fully real, and tangible space somewhere in, and above your place...Four simple walls of brick, that meet in four simple corners, extending, up-ending... How could it be, that a drop of rain, cannot I stop thee?Jack : )PS- This threads too long & Life's too short...If you want me to"kick-it," then send me a ticket.

  10. Gregory_Baron | Feb 27, 1999 06:58am | #23

    *
    Can anyone help us? We have a new brick masonry chimney which seems to leak through the brick. All necessary flashings are in place and in good condition (leaded copper).Chimney has been sealed with commercial sealants,to no avail and the flue has a cap.During rain the chimney which can be observed in the attic begins to get damp mortar joints then eventually becomes soaking wet as the rain continues.

  11. day | Feb 27, 1999 06:58am | #24

    *
    >seems to me that you need to check the roofing around the chimney. the most common mistakes can be found at the top where the saddle overlaps the shingles. also check that the water is not backing up the saddle under the shingles they should be sealed to the copper wit a GOOD sealant not some hardware store special. Vulcum brand is a great sealant for masonry and copper as well. check your comercial roofing supplier for metal roofing they should have a better sealant .

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