Thread: Chimney leak: no solution found yet

We have a chimney which has been flashed 3 times in the last year by 2 different companies (no change in leakage), new chimney caps for round flue and dummy flue (did not have one before), new chimney crown wash with professional epoxy, chimney was tuckpointed and then coated with water sealant (the back crack has opened up again as shown in the picture.

I believe this is due to moistureI have tried tarping an area at a time before rain falls, and what I determined was that it was leaking at the round flue (water heater/furnace). I changed the cap and it still leaks, although it appears not as much. I believe some of the problems are due to the fact that the chimney crown does not extend much beyond the outer surface of the chimney. Any suggestions or other ideas?


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If the flashing is not inset to the mortor joints, reglets, I would not concider it properly flashed.

Is that flashing actually inserted into the chimney between the bricks or into a groove cut in to the brick, or is it just gooped on there with a wish and a prayer. Application looks suspect to me.
Also if a crack has opened after recent fix you should be getting them out to fix again. None of that work looks grade A

Possibly also, water is getting into the flue, because the top of the cap is small and water is dripping down the inside of the liner and getting in through the gaps in the flue liners.
Installation of a slate cap that covered the whole top of the chimney and causes water to drip outside of the exterior edge would certainly take the top and flue liner sections of the chimney out of the equation and would be adding value to the house.
Yeah, easy for me to spend your money, sorry.

The flashing should be installed like this:

I don't think its a flashing problem but the quasi cement cap. Water is likely getting in where the cement meets the top row of the brick as it cannot be sealed effectively. I would be inclined to put a proper cement cap which has sufficient overhang.

Originally Posted by Raymond Wand

I don't think its a flashing problem but the quasi cement cap. Water is likely getting in where the cement meets the top row of the brick as it cannot be sealed effectively. I would be inclined to put a proper cement cap which has sufficient overhang.

RW: I might also suggest a sheet metal cap/screen for redunancy. However, almost all chimney leaks I have encountered are realted to poor flashing techniques.

Good idea. Now I know why you get the big bucks $!

Re: Chimney leak: no solution found yet
The flashing should be installed like this:

Attached ThumbnailsThis picture indicates that the flashing will direct the water over the underlayment and under the shingles instead of directing the water over the shingles.Or am I missing something?

Originally Posted by Michael Garrity

Re: Chimney leak: no solution found yet
The flashing should be installed like this:

Attached ThumbnailsThis picture indicates that the flashing will direct the water over the underlayment and under the shingles instead of directing the water over the shingles.Or am I missing something?

MG: You are missing the fact that this is directly from the NRCA's Steep Roofing Manual. Want to dance? Dance with them.

Originally Posted by Michael Garrity

Re: Chimney leak: no solution found yet
The flashing should be installed like this:

Attached ThumbnailsThis picture indicates that the flashing will direct the water over the underlayment and under the shingles instead of directing the water over the shingles.Or am I missing something?

I think that is an older Illustrated Homes picture, they had a few that had some wrong details that were corrected in newer versions. The pan part of the flashing should have a raised edge to keep the water from running onto the underlayment.

Originally Posted by Scott Patterson

I think that is an older Illustrated Homes picture, they had a few that had some wrong details that were corrected in newer versions. The pan part of the flashing should have a raised edge to keep the water from running onto the underlayment.

SP: Yep. That is correct. I've been using that to illustrate the reglet. NRCA's does not show that detail. Pardon moi.

Originally Posted by Michael Garrity

Re: Chimney leak: no solution found yet
The flashing should be installed like this:
Attached Thumbnails

This picture indicates that the flashing will direct the water over the underlayment and under the shingles instead of directing the water over the shingles. Or am I missing something?

No Mike,
You're not missing anything except the fact that you're looking at an illustration... If this illustration were factual... this chimney would be covered in simulated brick vaneer and the flashing material would be as thick as that vaneer....

The shingles won't (shouldn't) end that far away from the stop flashing and the counter flashing should stop far less that a finger's thickness above the shingle... (And, of course, it will be flaired out over the shingle as well...) As a matter of practice, if the counter flashing is installed correctly you can't get less that a putty knife blade between the counter flashing and the shingle without pushing the counter flashing down and binding the blade...

Sometimes a picture is worth a thousand words and sometimes it takes another thousand words to explain the picture...

That detail would be ok if the water was being directed towards the brick.That picture gives the impression that the flashing is on the downside.If so, that detail would be wrong.

To reiterate, for the unnecessarily picky MFs, the illustration was intended ONLY to illustrate the cap flashing kerf detail. Don't like the graphic? Post a better one.

Or, alternatively, STFU.

what a nasty little man you are.Why didn't you write something when you posted the picture and then everyone would know what you meant.

here is one

Originally Posted by Michael Garrity

what a nasty little man you are.Why didn't you write something when you posted the picture and then everyone would know what you meant.

MG: Nasty, perhaps. Little, not quite. Why? Because I am not perfect.

This is a long shot, ... but....
Are those hollow core bricks? If so the one which make up the cap may be prone to channelling water down from that inferior so-called cap. But then again, just a long shot guess.

Originally Posted by Raymond Wand

This is a long shot, ... but....
Are those hollow core bricks? If so the one which make up the cap may be prone to channelling water down from that inferior so-called cap. But then again, just a long shot guess.

RW: Good call. Wrong mix on the cap mortar and it would be a swiss cheese waterfall.

Chris: question, assuming this is a solid masonry chimney, w/3 flues, given you have stated one is a dummy, and the entire thing rests on a footing, where do you see the leak coming from? I agree with the others, most masonry chimney leaks are a result of faulty flashing, but you stated flashing 3 times, new flue caps, sealing of the brick, plus a an epoxy coating on the masonry cap. Not to mention the flashing itself is shown two shingle courses below the junction of the roof to the chimney face These are extrodinary measures.
I say this because, I have had ocassion to come in behind others where they had focused on the cap/top/roof flashing when in fact it was coming in at a much different location.
When all else fails. may I suggest the old water hose trick, with the assistance of a spotter at the leak location, starting at the base, allow the water from the hose to run against the flashing then the base ect, slowly working your way around and then up. Also the object is water volume not pressure, leave the nozzle off if possible. Of course be careful, and take precautions to not fall because of wet shingles, Believe it or not It sounds corney, but I've used this method may times to find hidden leaks points. Don't get in a hurry either, it can take time for water to work it's way through.
If nothing else it can aid in proving where the leak is not at.

Here is how I locate a leaking chimney, wall, bay etc. First need two sets of eyes. One on the roof and one at ground zero (where water was seen).
Take a garden hose and start at the shingles around the chimney. Moving very slowly applying to the shingles at full stream on all for sides. At that point you work your way upwards at a very slow pace on the sides. When you reach the top start at one end work to the other. You should be able to find water entry point by this process.

Another alternative is to hire Ron or any thermographer (be nice AD-D )

Originally Posted by Mike Schulz

Another alternative is to hire Ron or any thermographer (be nice AD-D )

Does IR work well on masonry? If it does, good call.

Originally Posted by James Skinner

Does IR work well on masonry? If it does, good call.

To a good extent, but also keep in mind that with the infrared camera on masonry (concrete block) you can also see all the mortar lines, all the cells, all the webs, all the filled cells, all the unfilled cells which should have been filled cells, and the walls which were unintentionally almost grouted solid.

Originally Posted by Jerry Peck

To a good extent, but also keep in mind that with the infrared camera on masonry (concrete block) you can also see all the mortar lines, all the cells, all the webs, all the filled cells, all the unfilled cells which should have been filled cells, and the walls which were unintentionally almost grouted solid.

Really, I had no idea, you would'nt have a photo example available? I'm really curious to see this. I would have thought in the case of a chimney like the one in this example the whole thing would be more or less a solid mass of the same color/temp allowing for thermal exposure differences, hot attics, sun/shade on the exterior, ect.

Originally Posted by Raymond Wand

This is a long shot, ... but....
Are those hollow core bricks? If so the one which make up the cap may be prone to channelling water down from that inferior so-called cap. But then again, just a long shot guess.

I'd suspect the cap as well. My first thought on seeing your photos was that the cap seemed awfully thin. They usually have a pretty good slope on them to help shed water. I'd also suggest the hose trick, but be plenty patient. It can take a while for the water to penetrate, depending on where the leak is.

Here's photo of a chimney cap problem that was a little easier to diagnose.

The flashing should be installed like this:

Attached ThumbnailsThis picture indicates that the flashing will direct the water over the underlayment and under the shingles instead of directing the water over the shingles.Or am I missing something?

That diagram shows step flashing, and not apron flashing. I think the confusion is in the angle of the diagram. It's only showing the top couple inches of the step flashing, and not the bottom part that overlaps the next shingle.

Chris,

Check you "Private Messages" at the upper right corner of this screen above "Log Out".

A.D. You always have the best drawings, diagrams where do you get them?

Originally Posted by James Skinner

Really, I had no idea, you would'nt have a photo example available? I'm really curious to see this.

James,

See attached photo.

Originally Posted by Tom Rees

A.D. You always have the best drawings, diagrams where do you get them?

TR: Obviously, usually from all the wrong places.

Yes, the flashing has been tucked into the groove. Thank you.

Originally Posted by Raymond Wand

This is a long shot, ... but....
Are those hollow core bricks? If so the one which make up the cap may be prone to channelling water down from that inferior so-called cap. But then again, just a long shot guess.

No, they are solid bricks.

Originally Posted by Jerry Peck

James,

See attached photo.

Impressive, I had no idea.

Chris try the hose method and tell us what you find. Wash caps here are just like yours. They have yet to get it right. They normally crack and wear off/ recede around the perimeter just like the picture in the left side bar.

Originally Posted by Mike Schulz

Chris try the hose method and tell us what you find. Wash caps here are just like yours. They have yet to get it right. They normally crack and wear off/ recede around the perimeter just like the picture in the left side bar.

Thanks. I have tried the hose method and was unable to determine anything. I will try it again. Thank you.

Originally Posted by Mike Schulz

Here is how I locate a leaking chimney, wall, bay etc. First need two sets of eyes. One on the roof and one at ground zero (where water was seen).
Take a garden hose and start at the shingles around the chimney. Moving very slowly applying to the shingles at full stream on all for sides. At that point you work your way upwards at a very slow pace on the sides. When you reach the top start at one end work to the other. You should be able to find water entry point by this process.

Another alternative is to hire Ron or any thermographer (be nice AD-D )

I would be able to borrow an IR camera. Would I use it right after or during a rain or when it is dry? I would assume the chimney would need to be wet. Thank you.

Just a thought. Check the ridge caps. water running of chimney might be getting under the ridge caps, if the caps are not seal together or a frigin nail

Look at that dummy cap then look at the round cap over the heater flue. If those bolts loosen, the cap will drop thereby blocking the flue and people will die. You should be using the rain cap listed for use with that liner.

I agree w/ the hatchet job on the flashing. Could have very porous brick and mortar. Find a contractor with Rilem tubes to perform a M.A.T. or Moisture Absorption Test. This will tell you if the previous water repellent treatment is effective or not.

Yes, it would be best to remove that crown, form up and cast a concrete crown with a 2" drip edge and bond break.

When you say leak that you localized to the heater flue, are you sure it is not flue gas condensation? Even with a liner, they can get damaged during installation or rot out from excessive condensation, esp. cheap brands.

Depending upon what 'stuff' they coated the chimney with, you may be getting indoor humidity condensation. Chimneys must breathe. You can coat chimneys as long as the product is 100% vapor permeable. I doubt that epoxy coating is. You need to find out what these products are, what their warranties are and their properties, esp. vapor permeability. If they used crap like hardware store 'water seals', you can do more damage than if left alone. The BIA has stated do not treat or coat unless 100% vapor perm. There are stainless steel vent tubes with ss screens to assist in venting otherwise ruined masonry that could be installed.

With all the mess done, I would say consider the cost of a rebuild but do your homework so it is done properly. You have gotten good advice on proper flashing and diagnostics such as IR.

HTH,
Bob

HTH,
Bob

Chris:May I assume that the water does not come from inside the gas vent/vent connector & that you already know you don't have the problem because of a nest/blockage?

Originally Posted by Phillip Bates

Chris:May I assume that the water does not come from inside the gas vent/vent connector & that you already know you don't have the problem because of a nest/blockage?

Yes, I have checked inside both flues. Thank you.

Well then, in light of the fact that Chris cannot find the leak coming from anywhere at all, and that all of our wonderful advice has come to naught, my suggestion is this: knock the GD chimney off the roof with a 12-lb. hammer, roof over it and solve the problem in a permanent fashion.

Two questions,

1. In the middle photo at the top of the flashing there appears to be two modifications to the flashing. Is it possible the caulk has opened up in these locations allowing water off the cap to run down into these openings? Remember it doesn't have to be a big gap or hole given the poor cap.

2. The second and third photo show what appears to be a metal flashing down from the chimney, am I to assume that is part of the flashing? If it is flashing why is it exposed just down from the ridge?

If he did the hose method like I explained he would of found it. Apparently it's not coming from the chimney or the shingles surrounding it.

Is that a metal flue running up the inside of the round lined flue?

Those are some pretty funny pictures. So much for keeping everything uniform.