Water in chimney clean out

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chadd77

Member
Jun 30, 2011
21
PA
Our home was built 3 years ago which consists of a masonry (stone) chimney. This is the first season which I am burning wood in our stove (only burned a dozen times the previous year) which is located in our basement. 2 months ago I noticed a horrid smell coming from our basement. To make a long story short, the smell was coming from water that was in our chimney clean out. The water was at the very top of the clean out which is about 6” deep. I’m not sure how long it was there but it had a very unpleasant odor. We never had a cap installed on the top of our chimney. I thought this is how the water was getting in and over 3 years of rain was enough to fill the clean out. Last night I rechecked the clean out and again it is filled to the top. Not sure who to call to look at this problem. My chimney is not insulated. Could that much condensation occur that it would fill the clean out? Is the water getting in from not being properly sealed around the roof? Could it be coming in below ground? I know it is going to be hard to tell without seeing it but I’m perplexed on who to call to look at this issue. Any help is appreciated.
 
Let's pick the low hanging fruit, here. You should put a chimney cap on. The last thing you want is a rotting squirrel in your clean out!! I'm assuming you have a masonry liner that extends out of the top of your chimney about 4 inches. Lowe's sells a nice chimney cap that will keep water and pests out of your chimney. If you are not comfortable getting on your roof and installing it yourself call a local chimney sweep and have him clean/inspect your chimney. Give him an extra $20 and have him put it on.
If the water returns once capped, we'll go from there.
Hope this helps!!
 
I'm no chimney expert but maybe a crack in an original (pre) cast masonry "drip cap" on top? Granted your home is less than 3 years old - but you never know. Maybe a sweep should check out the top parts, then (assuming the top looks ok, or regardless) take a peek from top down (camera) to see where the infiltration point is? Just throwing some thoughts out there. It doesn't take much - tiny breach, couple good rains. Water problems drive me crazy...
 
It the cap is of the type that is wire mesh and a top hat, any type of driven rain could be collecting. I use a type that is like say stacked paper cups ( 3 tapered rings) with a mushroom over the top nothing gets in it. Also unlike the mesh units it never collects much of anything unlike the mesh units which always seem to get a build up on the mesh. Seen a few of these pluged up enought to affect the draft of the appliance.
 
I do have the type of cap with the wire meshing. I live on the east coast and we did just have the bad storm that came through. I guess it's possible the rain came through the meshing. But I have had a lot of fires since then and you think a lot of the water would have evaporated.

I guess I'll have to start with a chimney sweep. I just fear I'll have a $200 bill and they won't be able to tell me more then I know now. But I guess I have to start somewhere. If anyone else has any ideas please let me know!
 
The next obvious question; is your wood properly seasoned?

Seasoned wood has a moisture content of 20% or below. Unseasoned wood can be as high as 60%. Think about how much wood you burn in a week - if 60 % of that is water then you are sending gallons of H2O up the chimney. If even a small fraction is condensing out you could fill you clean out in just a few days.

You could try testing your flue gas temperature as it leaves the chimney (involves getting up a ladder) - it will give you an idea if condensation is likely. temperatures too low let water condense.

Mike
 
I cut, split, and stacked all my wood a little over a yr ago. I keep it all covered with tarps. I believe my wood is dry as my fires start easy and always seem to burn great but I guess I can't rule anything out. What should the temp be as it is leaving the chimney?
 
I would think the rain storm is mostly the culprit, Can't rule out a cracked flue cover though. If you have the ability to get on the roof would pay to take a gander.

Heat rises so the clean out trap being down below would not see much of an effect, that is more of a dead air space

There is a possibility that water is weeping through the mortar joints. I have seen this on brand new chimneys as well as old, this not in the flue. You might be advised to use a sealant ( several types available as a spray application, using a common garden sprayer) Also the construction might have developed some cracks due to settling. Remedation of this would require filling the cracks prior to a sealant application .
 
Agree with blades- if you're ok to climb up (be careful, as always) have a peek - either you or a sweep doing a visual.

Kinda related - one bad rain storm last year - an unusual south wind hammered the rain into the south side of the house. It helped me discover (the hard way) a spot along a window jamb where I thought I had done a decent job sealing (and the house wrap had a tear there too). Drove the rain right thru. A couple cracks in your case might be an issue.
 
Could it be coming in below ground? I know it is going to be hard to tell without seeing it but I’m perplexed on who to call to look at this issue. Any help is appreciated.

Is that clean-out below grade? If so, are you in an area that has a high water table and have you ever had a wet basement and/or do you have a sump pump system?
 
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All good points. Thanks for all the info guys!

My clean out is below ground level. My entire basement is. We do have a sump pump that does run when we receive a decent rain. Last year during the flooding in the north east we did get some water in our basement but almost everyone did. Haven't had an issue since.

I think I am going to contact the guy that built our chimney and see what his suggestions are.
 
My clean out is below ground level. My entire basement is. We do have a sump pump that does run when we receive a decent rain. Last year during the flooding in the north east we did get some water in our basement but almost everyone did. Haven't had an issue since.

So then the obvious followup is has the sump been running lately? If it has then perhaps it could be ground water, if not then it still could be water leaking in from outside (just not pushing up from the water table), but if you sump has been busy then I'd give this theory a serious thought. Of course it all depends on just how deep this cleanout is etc...
 
Generally a chimney clean out ( bottom of it) is just a couple inches above the basement floor. Access door could be higher as it is not really there to collect or shovel ashes down into. As its name implies it is a access panel to allow cleaning of the flue from the bottom up. My current place the panel is 1" or so off the floor ( about 10" sq.) it is a pain to use for bottom up as the rod have to make just about a 90 deg. turn ( fiberglass ones just start splintering) my previous abode it was a couple feet above the floor although the cavity extended to the floor level.
 
The next obvious question; is your wood properly seasoned?

Seasoned wood has a moisture content of 20% or below. Unseasoned wood can be as high as 60%. Think about how much wood you burn in a week - if 60 % of that is water then you are sending gallons of H2O up the chimney. If even a small fraction is condensing out you could fill you clean out in just a few days.

You could try testing your flue gas temperature as it leaves the chimney (involves getting up a ladder) - it will give you an idea if condensation is likely. temperatures too low let water condense.

Water still present in the wood is the least of the problem. Wood is primarily hydrocarbons. When you burn hydrocarbons you combine oxygen with them to make carbon dioxide and water. How much water? It has been shown that a pound of dry wood fiber contains enough hydrogen molecules to form about .54 pounds of water when burned to completion. That comes out to about 400 gallons of water from burning three cord of seasoned wood - over three times the water that was originally in the wood at 20% MCdb (about 16.7% water by weight). Add that to the approximately 125 gallons trapped inside the seasoned wood and you have a whopping 525 gallons of water going up the flue each season .

Most of that goes up and out the stack, but as you said, if you burn too cool the water can condense onto the flue walls and run down the pipe. That's why it's important to put the crimped end of the pipe down so it rests inside the non-crimped end. That disgusting water will run down the pipe that way rather than all over your floor. It's also another good reason to burn your stove hot. Keep the top of the stack above 212F and you avoid the issue.

Of, course, letting all that water condense inside the home adds back all the heat originally lost through evaporation, but.... <>
 
When you first start a fire should you get some condensation in you chimney? I have been paying close attention to this and have noticed when starting a fire I get a decent amount of condensation that is running down my chimney. Not sure that is the root cause of my problem but I was surprised to be able to see it dripping/running down into my clean out area. After the fire has been burning for more then 20 minutes the condensation stops. Is this normal or could this be my issue?
 
We had a problem much like your. It was 53 y/o house, had a trap door on the fireplace floor to brush the ashes into, and then you would go down in the basement to the clean out to periodically clean up ashes. that clean out would have water in it, and with a heavy rain, would fill and leak out onto the basement floor. What we found (purely by accident), was digging down outside where the Chimney meets the foundation about a foot down, was a slight seperation between the two (Cimney/House Foundation)....very slight.....I sprayed water, and sure enough, it leaked.....I sealed the seperation, backfilled, and never had another problem.....had a Chimney guy tell me I needed the top foot of my Chimney redone at $1,500. How did we find this???....I was outside hosing down the windows and siding, and the Wife was in the basement, and yells out "It's leaking again"......without saying anything sprayed more in that corner, and she yells.."It's leaking alot now"....pure luck:cool:
 
We had a problem much like your. It was 53 y/o house, had a trap door on the fireplace floor to brush the ashes into, and then you would go down in the basement to the clean out to periodically clean up ashes. that clean out would have water in it, and with a heavy rain, would fill and leak out onto the basement floor. What we found (purely by accident), was digging down outside where the Chimney meets the foundation about a foot down, was a slight seperation between the two (Cimney/House Foundation)....very slight.....I sprayed water, and sure enough, it leaked.....I sealed the seperation, backfilled, and never had another problem.....had a Chimney guy tell me I needed the top foot of my Chimney redone at $1,500. How did we find this???....I was outside hosing down the windows and siding, and the Wife was in the basement, and yells out "It's leaking again"......without saying anything sprayed more in that corner, and she yells.."It's leaking alot now"....pure luck:cool:
The fire God was looking upon you, nice savings on not getting ripped off. I would stay away from the guy that tried to take you to the cleaners.
 
Hi I have a similar problem. I have a house built in the mid 40s with a masonry fireplace. There are 2 clay tile lined flues (one for the fireplace and the other was for an old oil burning boiler) about 2 ft apart and both have clean outs in the basement near the floor. The fireplace one stays dry but the old boiler one (no longer used) fills up with water after a heavy rain. The top is completely sealed and I'm certain it's ground water. There's an old metal flue pipe (tee) that comes thorough the foundation a few feet about the cleanout about a foot below grade. During the last storm I stuck a mirror in there and could see water dripping in from below the metal flue. Somewhere in below the metal flue and the cleanout it transitions to clay tile. Anyhow, I'm thinking of dumping concrete down through the metal tee and filling it up the cleanout to the bottom of the tee. I can't see any reason to ever put this flue back in service so is there any reason I shouldn't do it? If so what kind of concrete should l use? The chimney sweep I hired said to just block it off with a metal plate. I assume he meant to just replace the ash door with a solid plate but my wife wa the one who talked to him so I'm not sure. Anyhow, I don't like the idea having water pooled behind a plate. I think that would just cause more problems down the road.
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