Any Chimney Experts?? leaking water...

[Sled Puller]

Red brick Chimney, built in 1988, up the middle of the house, properly lined with clay flue pipe.



2 years ago, we went to a more efficient furnace, and put 5 inch round pipe inside the chimney, as per what the furnace called for.



About a month ago,Inside the house, the mortar joint started to leak water.

Today, all three exposed sides are oozing, about a foot below the ceiling, and one is actualy running out, covering at least a square foot!

What the heck is going on, and how do I fix it?



Thanks,

Gene

 

[ftb87]

I'm not an expert but... . I would check you rain cap. Does it extend past the top of the brick chimney?



I'm thinking the water is wicking down the new insert.





Frank

 

[KMC]

Are you sure the water is coming through the brickwork from the inside? Water on the inside would most likely take the path of least resistance and show up down below in the firebox.



The more likely scenario is that you have a leak where your chimney is in contact with the roof on the outside. A piece of flashing is loose or something. Water is traveling down the outside of the brickwork in the attic and becoming visible just below the sheetrock in the cealing of you room. Probe around and see if the sheetrock is wet or go up in your crawl space and/or on the roof and look at the area in question. Bring a flashlight and go when it is raining for best results.



If it is on the outside then get a caulking gun and a tube of Henry's 509 mastic. Use it to seal around all the edges of the flashing. Then in the summer when it stops raining you can replace the flashing, etc. or go for a more comprehensive fix.



Ken

 

[Sled Puller]

Yes, it is definately leaking from the INSIDE, about 4 courses down from the ceiling. Then running out. Drywall is perfectly dry from that course up.



Like a joint in the clay liner. Could condensation be causeing this? I can't believe I have a leak up there, but I could. Too much ice on the roof right now.



The rain cap, I believe, is on top of the clay liner, but NOT the whole chimney.



Pretty good chance that rain is running off the cap, down the liner between the brick, then coming out where there is a gap?

The plot thickens!

 

[KMC]

Yes, this is interesting... Most caps afix to the clay flue tile which are usually 8x12, 12x12, or 12x16 and do not overlap the entire chimney and don't need to. There should be between the outer edges of the brickwork to the flue tile in he center a mortar/quickcrete crown about 2-3 inches thick that effectively seals the top of the chimney. Crowns eventully crack and leak and need to be redone. But the ones I have had to redo are usually much older than 14 years old. Although with construction these days anything goes. If the crown is cracked or pieces are missing and newer "hollow core" bricks are used, the water could be traveling down the middle of the outer coarse of bricks and then moving laterally to the outside a short distance. If the leak is deeper within i. e. at the metal insert or the flue tile it doesn't seem likely that water is going to move lateraly so far through a flue tile and coarse of bricks to the outside. Somewhere gravity is going to get involved and move it down... . Unless there is some sort of obstruction and the water has built up enough head so that is pressure driven???..... This is weird!



Is your house a two story?



You mentioned ice up above. If you did have a crack in your crown at the beginning of winter, I imagine all it would take would be a few freeze-thaw cycles to make that crack a whole lot bigger.



Not really an expert but I did do some masonry work, rebuilt a few chimneys, etc. for a couple of years before I got going in my profession.



Ken

 

[Sled Puller]

I think we have it here.

There is a mortar crown, which was fine when the cap went on. The side that leaked first is the side that the weather comes from, and from the weather we are having, I assume we had ice/snow build up on that side, which very well could have froze and cracked that crown. Today we had a fast thaw, and the water gushed out.

Supposed to warm up tomorrow, I'll get up there and stuff some caulking in any crack I can see.





Ok, now what do I do to get the stains off the brick/mortar?!!?!?

 

[KMC]

TSP works ok for some things.



Muratic acid and wire brush for the heavy stuff. Kind of nasty to work with but it does the trick. It may cause some discoloration of the brick so you might try a small area first. Make sure you keep in off of you and anything metal.



Viniger can also be used as an acid - but it stinks! No pun intended...



There are also some commercial type cleaners available.



Ken

 

[Rambling]

Maybe..

Maybe the cement cap itself doesn't seal anymore.

Sounds like a problem I had(home built in '87).



I caulked every crack I could find. Added cauling at the base. Still leaked.



I put waterproofing on the cement cap and haven't had a leak since. Do have to reapply it now and then just like a wood deck.

 

[Chris N5CWM]

Could be..

My neighbor had a similar problem.



Basically the mortar was wicking water

and it was pouring in down the walls

and made a big mess, lots of damage.



He ground out the mortar between the

bricks and put in a latex based mortar

that is water tight.



So far he has no problem with the leak

anymore.

 

[Freddbull]

Originally posted by Sled Puller

Red brick Chimney, built in 1988, up the middle of the house, properly lined with clay flue pipe.



2 years ago, we went to a more efficient furnace, and put 5 inch round pipe inside the chimney, as per what the furnace called for.



About a month ago,Inside the house, the mortar joint started to leak water.

Today, all three exposed sides are oozing, about a foot below the ceiling, and one is actualy running out, covering at least a square foot!

What the heck is going on, and how do I fix it?



Thanks,

Gene

gj

I hope I'm doing this right. The higher efficient model heater's exaust gasses are much cooler than the older and less efficient ones, Some even have tubing to direct the excess condensate. the exaust gasses contain constderable moisture and will cause the condensate to liquify on the cooler surfaces of the chimney walls, especially on longer chimney runs. A blower fan to rush the cooler gasses along during the firing cycle before they cool enough to condense on the wall,may help. A good local plumbing supply house should be able to guide you. Your local utility as well.