DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (
-   Concrete, Stone & Masonry (
-   -   Baffling chimney issue… (

hotot 03-02-2012 09:03 AM

Baffling chimney issue…
6 Attachment(s)
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

Tom Struble 03-02-2012 10:34 AM

i think thats ceosote:eek:get a real pro chimney guy in there like right away

joecaption 03-02-2012 10:45 AM

Looks like that to me to.
A clearer picture looking up where that chimmney goes through the roof and one of the chimmney outside would be nice.
It looked like the wood was covered with black fungus in the fuzzy picture you posted.
That's nice when people try and fix a flasing leak by sealing it from inside the attic, not going to happen.

hotot 03-02-2012 10:46 AM

FYI it is a natural gas furnance and natural gas water heater. It could be old ceosote that has lined the chimmey when they used a wood stove 30+ years ago that is coming though.

Tom Struble 03-02-2012 10:48 AM

old creosote don't make it more better imo:no:

hotot 03-02-2012 11:07 AM

I did send the pictures to two chimney guys in the area this morning also.

The wood is not covered with any fungus. It is just water stained. The white you see is just stain streaking. Some of that black tarry stuff is on the wood also, I think it has dripped over from moisture where the roof meets the top of the chimney. I can try and get a better picture. As for the outside it is a tight sealed chimney, I can try and get a picture of that, but I would guess it won't help. The brick is sealed above the roof and is tight with no visible issues of anything. And as I said the flashing is very well sealed. The liner does have a cap on it which when the furnace is running I see the steam getting blown down towards the chimney.

Exhaust heating up chimney or roof around chimney ?

I had a contractor out for a different reason yeaterday who checked it out and told me he would not touch it with a 10 foot pole, because he could not say for sure what was going on. At least he was honest. He had no idea why it was doing what it was doing and in his 20 years had never seen anythign like it...

Michael Thomas 03-02-2012 11:24 AM

On (strong) possibility is that the liner for the gas appliances is defective/disconnected somewhere within the chimney, and water condensing within the chimney above the roof is saturating the masonry. This would be consistent with the observation that: 1) this is a winter problem and 2) the chimney is wet on all sides.

If so, you will almost certainly observe substantial deterioration at the exterior of the chimney above the roof.

hotot 03-02-2012 12:11 PM

6 Attachment(s)
Yes I agree the disconnected liner is a strong possibility. The chimney guy who installed the liner in 2003 (thanks former home owners for leaving all your house receipts!) is supposed to call me this afternoon.

I feel like it has gotten worse the past few years (leaks don't usually get better). Makes sense all the moist hot air collects up above the disconnect or seeps out a hole. I still get a lot of exhaust from the chimney though, but I don't know how much it should be. I never liked the cap as I always felt like it just pushed all this exhaust onto the roof.

However there is NO brick or mortar deterioration that I see above the roof. BUT in the attic the mortar towards the top has puffed a bit more then the bottom but it all still seems solid.

But above the roof the chimney has this blue sealer on it and the 18 inches right above the roof is well sealed in a black tar substance. And like I said several people have looked at it from the roof and it looks perfect.

So possibly in the last few bricks above the chimney it is leaking but under the flashing and dripping some of the tar with it when it seeps through and we just can't see it under the flashing?

Here are some better pictures of the insertion point of the chimney into the attic (note the spray foam was there before I bought it). And a few from outside, but I did not go up and take pictures right next to it right now.

hotot 03-02-2012 12:12 PM

5 Attachment(s)
more photos showing all sides at top

Tom Struble 03-02-2012 12:24 PM

i wouldn't touch it with a 20' pole:no:

AndyWRS 03-02-2012 07:49 PM

I have been in the roofing business for 20+ years and i have seen a number of chimneys however, i have never seen anything like that.

Get a chimney pro to check that out, that looks scary to me.


What is wrapped around the chimney where it meets the roof ? Looks like a giant tar job...but its difficult to tell in the pic.

hotot 03-03-2012 11:46 AM

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.


BigJim 03-03-2012 02:30 PM

I had a chimney do that and it looked just like that also, it was condensation, warm air hitting the cold air and cold brick at the top. The temps never got hot enough to dry out the condensation.

hotot 03-03-2012 08:48 PM


What was the cause of your issue and what did you do to fix?

BigJim 03-03-2012 09:45 PM


Originally Posted by hotot (Post 869598)

What was the cause of your issue and what did you do to fix?

I was using a wood heater that would burn all night with one load of wood. It burned so low the chimney would cool down at night and the warm air (smoke) would condensate. There was nothing I could do about it, It was like that when I moved from there. Sorry I couldn't be of any help. I wonder if insulating the chimney would help it any?

All times are GMT -5. The time now is 08:21 AM.

vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.

Search Engine Friendly URLs by vBSEO 3.6.1