Water Leaking Through Brick

[WoodChopper92]

Hello all,

TL:DR At the bottom.

Hoping for some input or advice here. My house has a 2 story fireplace in it with 2 flues. One flue vents the main floor fireplace, the other vents the basement fireplace. Every spring that I have owned this house (2021 to present) I have had water begin leaking through the bottom two or three layers of brick and mortar in the basement (see pictures).

After consulting with a chimney inspector, the first summer I dug out all around the chimney and did a bunch of waterproofing work. It happened again spring of 2023, so I had a new chimney crown put on, and a lot of the mortar chiseled out and re-tuck pointed (all done by a well-known and reviewed chimney company in town). It had some major cracks and decaying mortar joints prior to this.

I live in Michigan and it has been very warm with a lot of rain melting all the snow for this past week. Sure enough, this afternoon water started leaking through the brick once again. The flashing between the roofing and shingles got re-sealed with some type of caulk while they were up there too. I run a wood stove insert on the main floor and a pellet stove insert in the basement. Both of those are dry and have proper rain caps and stainless steel liners. The ash door clean out is on the exterior of the chimney, and the inside seems to always be dry.

Any ideas where to go from here? This is the only place in my basement that I get water leaks. I have no idea what to check next.



TL:DR The bottom of my chimney weeps water through the bricks every spring. Have rebuilt the top part of the chimney and had the flashing joints resealed. I have water sealed the exterior underground section. What do I look into next?

 

[EatenByLimestone]

Can you get up to the roof to take pictures of the crown and flashing? There are drains that can be installed into chimneys, but you really shouldn’t have that much water getting into them to begin with.

 

[WoodChopper92]

Can you get up to the roof to take pictures of the crown and flashing? There are drains that can be installed into chimneys, but you really shouldn’t have that much water getting into them to begin with.

Here are some pictures. It's dark out so hopefully you can still see details alright.

There's another layer of black flashing that is under the shingles and under the brown flashing you see here. The vertical ends of the flashing on the sides of the chimney aren't caulked, but everything else seems to be.

The crown is intact, has a drip edge, expansion joints for the flues, and a slight angle to drain water away from the house. Thanks for taking a look!

 

[EatenByLimestone]

I’m not seeing anything screaming at me. Maybe the black flashing that we can’t see has a hole? Being at the peak you’re not going to get a ton of water being pushed yp against the outside. You mentioned it being 2 stories tall. What rooms are pushed up against the chimney? Do any of them have water pipes? We once installed baseboardtrim around a dry walled over chimney passing up through a kitchen. Somebody used the clearance to combustible space to run a water line. We didn’t know it was there until we put a finishing nail into it.

@bholler , any ideas?

 

[vatmark]

Is it possible the water is being wicked up from the ground? It seems weird to me that if it were leaking from high up you would see signs of water elsewhere above this area.

 

[WoodChopper92]

I’m not seeing anything screaming at me. Maybe the black flashing that we can’t see has a hole? Being at the peak you’re not going to get a ton of water being pushed yp against the outside. You mentioned it being 2 stories tall. What rooms are pushed up against the chimney? Do any of them have water pipes? We once installed baseboardtrim around a dry walled over chimney passing up through a kitchen. Somebody used the clearance to combustible space to run a water line. We didn’t know it was there until we put a finishing nail into it.

@bholler , any ideas?

The house is 3 stories total, including the basement. The chimney is on a 2 story (basement and main floor) kick-out. Both rooms that are against it are a sitting room/family room. There are no water lines run into this section of the house. This only happens for a couple weeks every spring when a bunch of snow melts with heavy rains.

@vatmark, The first project I did trying to fix this was underground waterproofing. When the chimney reaches the ground, the brick shifts inwards and it is surrounded by the foundation concrete. I dug down to and exposed the footing. There was a thin vertical crack in the center that I filled with concrete caulk. Then I sprayed the entire area with multiple layers of Lastiseal (brick and concrete sealer). After that I painted 2 or 3 coats of rubber paint over it all. Finally, I glued 6 mil black plastic sheets over the whole area. So if the water is coming in through the ground, it would have to be underneath the footing. The house does have a drain system in place that goes to a sump pump, so that doesn't make sense to me, but it also seems like the most likely explanation.

 

[WoodChopper92]

Now that it’s day, here’s the chimney from the outside.

 

[Solarguy3500]

My bet would be ground water coming up through the floor and moving through the concrete/brick through capillary action. Concrete is actuality quite porous and water can move freely through it.

Your excavation and waterproofing efforts on the outside basement wall were a good effort, but if there is no moisture barrier under the concrete floor, water will always be able to come up through it and your description of when it happens (spring) makes sense because thats typically when groundwater is the highest.

The fact that there is a sump indicates that groundwater is a known issue there. I have the same problem with my house. It was built in 1935 and back then the understanding of how water moves through concrete wasn't what it is today, and the use of barriers under basement floors wasn't exactly mainstream then. Short of jackhammering your entire basement floor and redoing it with a barrier under it, there may be limited options for dealing with it. I have a ground rod that comes up out of my basement floor, and in some of the recent heavy rain events we've had, there has actually been water bubbling up out of the floor around that ground rod.

 

[Max W]

Getting the water from the downspouts further away from the chimney may not solve the problem but it could help make that gournd less saturated.

 

[WoodChopper92]

My bet would be ground water coming up through the floor and moving through the concrete/brick through capillary action. Concrete is actuality quite porous and water can move freely through it.

Your excavation and waterproofing efforts on the outside basement wall were a good effort, but if there is no moisture barrier under the concrete floor, water will always be able to come up through it and your description of when it happens (spring) makes sense because thats typically when groundwater is the highest.

The fact that there is a sump indicates that groundwater is a known issue there. I have the same problem with my house. It was built in 1935 and back then the understanding of how water moves through concrete wasn't what it is today, and the use of barriers under basement floors wasn't exactly mainstream then. Short of jackhammering your entire basement floor and redoing it with a barrier under it, there may be limited options for dealing with it. I have a ground rod that comes up out of my basement floor, and in some of the recent heavy rain events we've had, there has actually been water bubbling up out of the floor around that ground rod.

Michigan is definitely know for groundwater issues. If you have a basement here, you have a sump pit and pump. I've added another photo here that shows the interior and the fireplace. Water ONLY comes in through the brick of the chimney. And only through the bottom couple layers. Not anywhere else. This fireplace is below grade, and as stated above, the chimney is surrounded by concrete at this point.

Water being pushed up from below grade is my worst fear since, as you stated, there isn't anything I can do to stop that. This is also the only area in the entire basement that has water issues.

@Max W I actually forgot to mention, but the first year I had this house there were no gutters, and there was dirt piled up against the chimney. I added that little retaining wall to push the dirt back, and had the gutters and downspouts added. I graded everything to flow away from the house into a low spot that then flows into the backyard. All that seems to have made no difference though .

 

[stoveliker]

I don't understand why construction here does not learn from expertise elsewhere.

I grew up in a country where 25-30 pct of land is below sea level. Ground water in most of those places is 2 ft below grade.
Yet every home has a (concrete) basement, and lines (water, nat. gas, and electric (!) come in underground.
No leaks. Sump pumps are not known and would be regarded as a poor substitute for good building practices.

This doesn't help the OP, but concrete doesn't need to be leaky.

That said, OP, given that you don't have problems elsewhere, I would consider settling and resulting cracks as a potential cause - evidently the concrete itself is fine. If the water table was up to your slab, and the slab is leaky concrete, you'd have seen water elsewhere too

Having a heavy chimney on the slab may have induced cracking?

 

[WoodChopper92]

I don't understand why construction here does not learn from expertise elsewhere.

I grew up in a country where 25-30 pct of land is below sea level. Ground water in most of those places is 2 ft below grade.
Yet every home has a (concrete) basement, and lines (water, nat. gas, and electric (!) come in underground.
No leaks. Sump pumps are not known and would be regarded as a poor substitute for good building practices.

This doesn't help the OP, but concrete doesn't need to be leaky.

That said, OP, given that you don't have problems elsewhere, I would consider settling and resulting cracks as a potential cause - evidently the concrete itself is fine. If the water table was up to your slab, and the slab is leaky concrete, you'd have seen water elsewhere too

Having a heavy chimney on the slab may have induced cracking?

The water table here can reach to within a foot or two of the grade of my backyard, and the slab is about 4 feet deeper than that. And the fact that it only happens in the spring would indicate to me that the rest of the year the ground can absorb downpours. So its very possible the chimney caused a crack in the slab underneath itself. Is there anything I can do to get at something like that? Or would I need to do an interior drain system that involves jackhammering through the slab?

 

[stoveliker]

The water table here can reach to within a foot or two of the grade of my backyard, and the slab is about 4 feet deeper than that. And the fact that it only happens in the spring would indicate to me that the rest of the year the ground can absorb downpours. So its very possible the chimney caused a crack in the slab underneath itself. Is there anything I can do to get at something like that? Or would I need to do an interior drain system that involves jackhammering through the slab?

Unfortunately I don't know.
Maybe there are ways to inject something into cracks under high pressure. I would think that if you mess with the structural integrity of the slab under the chimney (jackhammering), you might induce.more.cracks.

 

[jjam]

I would remove the brick that are leaking and look where it is coming in

 

[WoodChopper92]

I would remove the brick that are leaking and look where it is coming in

Would it be safe to take bricks out of the bottom of the chimney? I don’t want to cause any structural issues.

 

[BigJ273]

My money is on groundwater as well. Everything else looks buttoned up pretty well

 

[bigealta]

You could try an Exterior sump pit, at 4 ft it is getting a bit deep but do able. You will know exactly where the water is if you do it.

I have a 2 1/2 - 3 ft deep one at my Utah house. It's used during the spring melt season. Works well, and i have a hose to siphon so it can work with no electricity. An easily removable pump is also in it so there are options.

 

[bigealta]

An older pic when i first put it in.
Both Pump and hose siphon running here.