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Baffling chimney issue...

Post in 'DIY and General non-hearth advice' started by hotot, Mar 2, 2012.

  1. hotot

    hotot New Member

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    I have a main house chimney (1930's) that is having a water problem. There are two liners in it one which has a furnace and water heater that are used regularly and one that is a coal stove that I never use.

    I have lived at this house 2.5 years. When I moved in I noticed tarry drips on the chimney in the part through the attic. And that someone had spray foamed the part where the chimney meets the roof. I suspected there was a problem with the flashing and I would need to repair. I do have a receipt dated 10/24/2003 where a 316TI chimney lining was installed for the existing furnace.

    The problem only appears to happen in the winter, and after myself and numerous others have gone on the roof and looked at the flashing I have pretty much eliminated that as a problem. The flashing looks very tight and good. The top of the chimney was slightly concave so a small amount of water pooled, but the seal seemed very tight and we redid it so the water would flow off the top this fall.

    But this winter we have water coming out like crazy again. It leaks from all 4 sides almost equally (another sign it is not flashing).

    In doing research and looking at it my newest suspect is that the liner has a hole in it and moisture is getting trapped in the chimney and leching it's way out. Is that possible? If I could identify what the tarry substance is that might help and confirm. Are chimneys lined with something that would look like this when mixed with water?

    The other possibility is condensation. The chimney might be warmer and moisture in the attic air is condensing on it. The attic is ventilated good but not great (it is a hip roof so the ridge vent is small and I don't believe there are enough soffit vents, but at least it has some). The attic is insulated good but not great (there are some can lights and only one layer of insulation so warm moist air from the house might be getting up. The bathroom fan is not vented through the roof but is right tight to a separate ridge vent 30 feet away from the chimney and there are no water stains on the wood were it exits.

    Another question is if the water is coming out the chimney why do I have water stains and drips on the wood above it? Well this might actually be condensation of the water leaking from the chimney? Or proof that it is condensation after all? The chimney exits at the very top of the roof right next to the small ridge vent.
    I am leaning slightly less towards this idea as if I look close it almost looks like the water is coming through the motor. However the motor all still seems solid.

    I am hoping someone might have seen this before and can give me some clues what it is! Thanks

    Attached Files:

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  2. BurnIt13

    BurnIt13 Minister of Fire

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    I can't tell you what that tarry stuff is but I have the same stuff on my chimney! My house was built in 1900 and has a single 6" flue in the chimney with a liner for the gas boiler and water heater. The heating equipment was a oil burning and at some point was converted to natural gas. I once asked a construction friend and he said roofing tar from years of new flashings around the chimney. I look forward to the responses....
  3. Butcher

    Butcher Minister of Fire

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    It's easy to be an armchair internet quaterback but. As someone who has reroofed 100's of old houses I will have to say you got some serious issues that I whould want to have looked at by a GOOD carpenter or mason. If tar was used to flash around the chimney then the job wasnt done right, I have never used tar to flash anything. It's hard to tell from the pics but it looks to me as if the rafters have seen considerable amount of water damage. You say it is a hip roof. Is there a saddle built between the chimney and the peak to shed water or just tar?
    [​IMG]

    It could also be due to the fact that over the years of burning oil up the flue and after the new liner was installed that the years of crud from the oil burner are leaching out thru the morter in which case a tuck point job might be in order. Not tryin to scare ya, just my 2 cents worth.
  4. Defiant

    Defiant Vermont Castings Geek

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    That looks like leeching, and I do not think it is tar, not an expert but agree with Butch, consult a mason or builder.
  5. rwhite

    rwhite Minister of Fire

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    Pics are a bit blurry but there looks to be a good bit of rot extending out from the chimney. I'm betting it's a roof problem more than a chimney problem.
  6. SmokeyTheBear

    SmokeyTheBear Minister of Fire

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    Find the clean out and on a bright sunny day use an inspection mirror and look at what's on the inside.

    I don't think it is going to be a pretty sight there either. It isn't likely roofing tar.
  7. benjamin

    benjamin Minister of Fire

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    How about a picture of the outside of the chimney? even a few from the ground is good enough.

    I'm guessing it's condensation from the wood smoke condensing on the underside of a metal cap and leaking through nonexistent flashing.
  8. laynes69

    laynes69 Minister of Fire

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    There appears to be some water damage to the roof. It looks like possible condensation inside the chimney itself. Over time that mortar can deteriorate. Is the liner insulated? If the liner isn't insulated, maybe the temperature difference between the attic (brickwork) and liner be causing condensation? If that's the case the liquid will come out of the joints as it collects on the bricks, especially if the chimney didn't have a existing clay liner. We had some condensation issues before lining our chimney. The water that came from the chimney was condensation. Once the chimney was lined and the liner was insulated the problem went away.
  9. hotot

    hotot New Member

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    Thanks for the info.

    I know it looks scarier then it is. There are water stains on the deck boards but everything is still very solid and for the most part dry. Also the mortar and chimney are all solid. And from the outside it all looks perfect. The more I think about it the more I think the liner (which I don't know if it is insulated but I would guess not) has a hole in it or bad seal and is filling the chimney with moist warm air. It is condensing where it exits the attic and dripping down and leaching out old creosote from when the chimney might have been for wood burning? Just a guess.

    I emailed the pictures to the guy who did the liner 9 years ago and he has never seen anything like it. I am going to talk to him tomorrow.

    I sent it to another chimney guy in the area who also did not know and will come out monday.

    Here are some more photos of the outside and inside.

    Attached Files:

  10. hotot

    hotot New Member

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    At one point someone had stapled insulation to the actual attic deck boards. That was obviously wrong and removed at some point. That is the fuzzy insulation remains you see in the pictures, that combined with the flash, old electric knobs, and the spray foam really make it look like a mess.
  11. Lighting Up

    Lighting Up Feeling the Heat

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    If that last picture is your roof and chimney were they meet. You have a roof and chimney flashing leak. Pictures of your roof will help but water takes the least path and I would bet it may look good from the roof but that roof rafter that touching the chimney looks wet. Get a roofer in there.
    md
  12. Hogwildz

    Hogwildz Minister of Fire

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    Looks like the counter flashing on the chimney is mucked(roof cement). If you go around it, you will most likely find it is cracked, and any water is running in. Could be the counter flashing was never installed with a reglet. Many times when roofs are redone, they tear the old flashings out, and don't bother resetting into the reglet grooves cut into the sides of the chimney. And instead they face mail it flat against the masonry and muck over it. That crap will crack, and it will leak. Your wood there needs to be replaced also. It is either rotted or charred touch to tell. If it is charred, you have other problems. Check the chimney flashing again and make sure the roof cement sealing it is not cracked, or there are no fishmouths or openings. The mortar could also be absorbing water and leeching it inside as was already suggested. I'd start by checking that flashing seal real good. I am wondering if that is just reglet flashing with may no base flashing on the deck side?
    Address is soon, before it gets any worse.
  13. granpajohn

    granpajohn Minister of Fire

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    Give that black gook the sniff test too.
    In my experience, if that sort of thing is creosote related, it smells like it.

    (I'm not an expert, but didn't notice anyone mention that yet.)
  14. basod

    basod Minister of Fire

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    That could be old damage from when the coal stove was in use, the soot washed back down around the flashing leak.

    Do you know when the roof was last replaced - or who pumped the great stuff up in the crack?

    I'd go up there and take a look at it next time you have a driving rain and see if its damp anywhere. Could have been fixed when the roof was replaced they painted the exterior and didn't fix all water damaged roof decking.

    I'd also wonder if the top block-off isn't to blame that or the chimney top coat could be leaking water back down the interior of the chimney and when it heat up the moisture is traveling through the mortar and leaaching down the brick face.

    If the top of the chimney was repaired at some point it could be newer hollow type bricks and not solid ones, the moisture would trap in these and wick out as well
  15. laynes69

    laynes69 Minister of Fire

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    It looks like creosote to me also. When water mixes with creosote forms an acid that will break down mortar. Very hard on chimneys. More than likely the chimney wasn't swept or cleaned before it was lined. I would pull the tin cap of the old thimble and get a peek on the inside. Even though the portion at the roof looks terrible, there's alot of moisture leeching from the bricks. Some of the areas had white stains, which is more than likely minerals leeching from the mortar.
  16. hotot

    hotot New Member

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    It MIGHT be solved!

    Ok So I racked my brain all last night on what it is. I just knew it could not be the roof as it is on all 4 sides, happens when there is no rain, is much worse in winter, and when I look at it (and others) it is very tight and well done up there.

    This morning I checked the clean out and everything looked fine.

    So I looked closer at the 3 items that go into the chimney. The furnace was just maintained a few months ago. When the guy did it he pulled the vent from the chimney and checked it all out and resealed it. The sealer was much more flaky then I would have thought. I guess I always assumed there was a liner that had the furnace and water heater on it (as the water heater exhaust was angled like it hooked into the furnace liner. And that the coal stove had a liner. However I looked closer and realized that no in 2003 a 316TI liner was installed for the furnace and the coal stove just vented into the large chimney area.

    Then I gave the 3 inch pipe that the water heater exhaust enters the chimney a look over. I had messed with it before and everything always seemed fine. This time I gave a a little harder yank and it broke the friction between it and the brick and realized that is just a pipe that barely enters the chimney and just terminates there.

    That did not seem right, this little 3 inch pipe exhausting into this what must be 18"x24" chimney (which I don't think is clay lined just brick).

    I got a hold of the guy who did the liner in 2003 and talked with him. He had all sorts of notes on this place. In 2003 he put in a 316T1 flexible liner for the chimney. He said he has done 10's of thousand of feet of this in his decades and only has had one with a hole (which he said resulted in a garbage burning house that burned laundry soap boxes from a washer right next to it, the company said soap can break down the liner). So he said no way it is the liner.

    In 2003 he noted the moisture problem but the home owner did not want to do anything. (Proof this problem has been there almost 9 years)

    In 2005 he was called again with the moisture problem and came up with water proofing quote which the home owner did not do.

    In 2008 he was called again and this time they sealed the exterior chimney with all these real good membranes and sealers. He said there is no way that is leaking up there it was the best materials you could use. Which seems to match up with what I see.

    In winter 2009 he was called again by the home owner saying it is still leaking. He wanted to investigate but never heard back from owner and they sold me the house in summer of 2009.

    We talked for a bit and I gave him lots of details and he had no idea and wanted to look at it. Then I told him about the water heater and he said that is it!

    He said with the BTU that thing produces it can exhaust several gallons and hour of water. It is filling that huge space, contacting the cold brick and condensing. The water is leaching out the brick and dragging old gunk on the inside of the bricks with it. The bricks at the top of the chimney are the coldest and that is why some is appearing on the wood.

    So far I have not been able to put a hole in this theory (unlike all the others) as it seems to be completely possible...

    Next step it to change the way the water heater vents and see if that is the problem.


    The good news is the chimney still seems very solid. And this is 9 years of water stains you are seeing on it so the amount coming though is not huge (most must be exhausting from the other chimney cap) but any water is not good. It might be a easy and not to expensive fix.

    Thoughts?
  17. benjamin

    benjamin Minister of Fire

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  18. laynes69

    laynes69 Minister of Fire

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    Nice, that would for sure cause the issue. Good thing you figured it out, easy fix.
  19. rwhite

    rwhite Minister of Fire

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    Sounds very logical. Natural gas produces quite a bit of steam as a byproduct. So is the furnace wood or NG? I assume wood since they installed a 316 liner.
  20. Butcher

    Butcher Minister of Fire

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    How old is the waterheater you have now? They dont last forever you know. If the chimney seems solid, rather than sticking more money into it you may think about getting a new high effency WH with a power vent and run it out the side of your home. The only problem with them is you will need an electrical hook up for it and room to run the PVC outside the foundation. Just a thought.
  21. hotot

    hotot New Member

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    Furnace is also NG.

    The water heater is 2005. I am certainly considering a power vent out the side. I don't want to do anything in the chimney because if by chance this is not the problem I don't want to second guess it, I want to eliminate it one way or the other. Also if we go out the side I can move my heater to a spot closer to the kitchen/bathroom for quicker hot water rather then the middle of the house where it is now to use the chimney.
  22. Lighting Up

    Lighting Up Feeling the Heat

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    hotot, if I'm understanding this it also does not sound safe if your Hot Water Tank is exhausting between the brick and the metal liner if it capped off on the top. One small crack in the mortar and you could have CO coming inside...again if I 'm understanding this right. Anyway sounds like your fixing it, great job figuring it out.
    md
  23. hotot

    hotot New Member

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    There are two caps on the chimney. One is the cap that is hooked to the liner. The other one is open to the open chimney (where the water heater and unused coal stove are venting into). So it should be safe as there is an exit, but thanks for teh concerns. We do have co dectors on all floors.
  24. rwhite

    rwhite Minister of Fire

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    I would check code being that there both NG you may be able to tie the water heater into the furnace vent.
  25. Hogwildz

    Hogwildz Minister of Fire

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    Put in an electric HWH and be done with all that.

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