Help - Water Leaks!!

Old 10-18-05, 12:07 PM
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Help - Chimney Has Water Leaks!!

We have a 3ft. by 11ft. chimney with a brick exterior. When we get heavy rain some water runs down the chimney block below the roof damaging parts of the ceiling and sheetrock walls. It also is coming through the masonry around the lintels of two of the three fireplaces. When we go into the attic we can see that all the block on the one 11ft. side that we have access to is very wet. On the 3ft. side that we can see, the two courses of block nearest the roof, towards the peak, are also wet.

The chimney’s brick exterior has some small holes in the mortar joints about 3/8 in. square. Some of these have been sealed with some kind of silicon caulk or adhesive. A couple of the mortar lines near the top of the chimney have been sealed/repaired with NP1. There is some moss growing in a number of the mortar joints, especially on the north side. The crown looks good with some minor repairs with NP1. The previous owner replaced the roof in 2004, just before we purchased it. The top of the counter flashing is embedded into mortar joints. It does not look like it is new but it is not corroded and is tight against the brick with no apparent holes or gaps.

Contractor number one said the problem is that the chimney is acting as a large sponge and once it’s full of water it is released and we get the water problems. His solution is to install flue caps, apply Drylock paint to the crown, clean and repair all the mortar, and seal the brick.

Contractor number two says the chimney flashing needs to be replaced and the mortar repointed.

If contractor one is correct we can do the job ourselves. If number two is correct we’ll look for a roofer with sheet metal expertise.

How should we proceed?

Last edited by Duke14052; 11-10-05 at 04:49 AM.
Old 10-18-05, 04:18 PM
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Number 2..........and,

I don't know how well those "sealers" work. You might have to do that every year or two.
Old 10-22-05, 05:48 PM
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The chimney flue Cap might help divert the water from going into the chimney. That's a cheap place to start. If you have water entering the house, the obvious place to look at is where the flashing meets the house and chimney. Get up there and Eyeball it. Think water shed. The flashing should make it possible for the water to just run past chimney and not pool or hang around. Go to the home center and get yourself a tube or 2 of roofing seal asphalt cement and apply to any places that look iffy, 6 bucks and a few minutes might save you a lot in the long run. Go luck.
Old 10-22-05, 06:20 PM
Join Date: Mar 2005
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Help - Water Leaks!!

It sounds like this has been an ongoing problem judging by the different attempts to seal, patch or repair.

A 3 x 11 chimney definitely needs a metal cap to shed the water and let it run off the the roof and not down the side of the chimney.

Sealing the joints between the flue and the masonry cap is normal preventative maintenance.

The one item both contractors noted was the repair of the mortar joints. Moss is a definite indicator of a problem. If there were some cracks, they should have been tuckpointed rather than temporarily patched. If there were some cracks a while ago, there probably are more now.

I would suggest having the chimney tuckpointed. Your chimney is a major structure and has many square feet of area getting the worst exposure of any part of your home. Assuming an average projection above the roof of 4', you have over 110 square feet of exposure to collect moisture. With that exposure and some cracks subject to wind while moisture is running down the face, there is good likelyhood of moisture entering.

After tuckpointing you can seal if you feel the brick have a high absorption.

Old 10-23-05, 04:08 PM
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What actually is tuckpointing? Is that the same as repointing the joint?
Old 11-10-05, 04:16 AM
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With fall here and all the rain we've had in NH it has taken a while to get a highly recommended roofer who had some time to work on our problem. When he started to work on it he discovered that there was no step flashing under the counter flashing, just ice and water sheild. The ice and water sheild was punctured in several places where the roof meets the chimney. He installed new ice and water sheild and step flashing over the existing ice and water sheild. As he was working on it we saw evidence of several other attempts to fix the problem at the roof/chimney. He also caulked the morter where it needs to be repointed - a temporary fix until spring - the soonest a mason will commit to coming here (NH is in the middle of a huge building boom).

The next heavy rain we still had the same problems as before. He suggested that sealing the masonry chimney and crown was the next thing to try and did it last week. He used a product called Seal Krete.

Last night we had another heavy rain. In the attic, looking at the small space between the chimney and the roof you can see the bottom of the ice and water sheild. It has water droplets on it. There is seepage or leakage on some of the block in the attic. Water is getting to the wall board causing further damage and dripping into the fireplaces. Bottom line - same problems as before.

We hesitate to install a metal cap because of the $2,000 quote we got and also because it would significantly change the look of the house. It is a contemporary with cedar and brick exterior. A cap big enough to cover this large a chimney would be very obvious. We also got quotes for a bluestone cap with brick towers - looks like between $3-4,000 but would blend in with the existing architecture much better. Either way a lot of money with no guarantee of a fix.

Any further suggestions would be greatly appreciated!!

Last edited by Duke14052; 11-10-05 at 12:52 PM.

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