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cinder block foundation wall cracking


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Hello. I am considering to buy a house in a waterfront and found many cracks in the basement cinder block wall. Some are vertical and some others are stair step crackings. The house is built in 1948 and once there was water infiltration through the basement walls, but never afterwards, that is what the real estate agent of the seller side says.

I attached a couple photos of the cracks below. First 3 photos are from inside the basement and last 2 photos are from outside the house. You can see some cracks patched up.

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What do you guys think is the cause of those cracks? Is this a settlement problem?

If so, how serious is it? Is this good idea to buy this house?

I am concerned if the cracks would give more problems after we buy it.

Thanks. Your advice is greatly appreciated. :-)

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You're in an area where your frost line probably goes down at least four feet. Without establishing shots of the inside and outside of those areas, it's hard to tell from the photos, but it looks to me like there'd been a drainage issue at the exterior that'd been allowing water to back up around the base of the foundation. When that water-saturated soil freezes it expands and can sometimes cause damage like that.

There's also supposed to be a footing drain installed around the base of that foundation wall to remove that water. If there isn't one, it's been placed in the wrong location, has become occluded with silt, or isn't deep enough and it freezes, you can end up with water in the basement and the same heaving issues outside.

Did you ask them what caused the water in the basement and what's been done to fix it? Find out who did the work, check them out to see what kind of a reputation they have, give them a call and ask them to tell you about what they found and what they did, and then talk to one or two local drainage specialists in your area to see what they'd have done under similar circumstances.

Maybe the issue has been corrected. The grading around that foundation needs to slope away from the walls at a rate of about an inch per foot for at least the first six feet. Does it? If it does now, but they tell you that it used to slope toward the foundation and they'd had to correct it, that would be a plausible explanation.

The water from the leaders (downspouts) also needs to be conveyed at least six feet from the foundation or into an intact tight-lined drain system that discharges to a drywell on the property or into municipal drainage. Does it? If the answer is yes, and they explain that the cause of the flooding had been broken or improperly oriented downspouts that were dumping water at the foundation, that also would be a plausible explanation.

However, if the owner tells you that the problem had nothing to do with either of those issues, and the owner claims that the issue involved the footing drains and it's been corrected, there's no way that anyone here can help you - you'll need to talk to a drainage specilist in your area. In the end you'll be left with the choice to either believe the seller or walk away.



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You stated that the house is on the waterfront. I would be curious as to how high the water table is.

So long as the house isn't floating, my thoughts are, being that the house is 60 years old, unless I saw something that led me to believe that those cracks are recent or if the pictures are simply typical of similar cracks all over the place, I wouldn't be too alarmed by them.

Like I said, unless there is more than the pictures dipict, my thoughts are that they have done whatever they are going to do.

Waterproofing cracks is easy enough. I prefer Hydrophobic Polyurethane. Injected under pressure from the inside. Since the walls are open, that's easy enough.

Like Mike says, make sure the exterior drainage is well away from the house.

If you do buy the house and wish to monitor the cracks, purchase a small microscope slide (glass). Using urethane adhesive, attach it across the crack. If the crack widens, the glass will break.

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photo 1) proves ongoing water instrusion..paint has been "pushed" off of the wall

photo 2) the same thing..stains around penetrations... efflorescence and the repair has opened since applied.

photo 3) corner joint broken and stair step crack since last painting

photo 4) stair step and some differential separation since last painting

Things are moving. Water is entering. Around here lake front homes are built on extremely fine soils that compact well but don't drain. The local glacial till is like crusher run...all sizes of aggregates that after some time become tightly compacted and hold water.

Drainage is paramount: large roof overhangs w/ fully functioning gutters can do a lot to keep foundations stable in poorly draining soils.

To be accurate: The block in the photos is concrete, not cinder.

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Sounds like there are no long horizontal cracks; those are the ones where the earth is pushing the wall inward.

It all looks like settlement caused by excessive moisture.

And, forget what the realtor says; they have no idea whatsoever how many times there's been water in the bsmt. I think there's ongoing water entrance.

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Hi everyone,

Thanks for your responses. It gives me a very good starting point.

From the outside of the house, it seems like most of the measures you’ve mentioned were already in place.

  • The grading had a slope going away from the house
  • The water from the downspouts was redirected away from the house

  • In picture 4, we can see that there is some black coating on the lower part of the foundation. I assumed this was an external membrane used to waterproof the foundation from the outside. However, I still don’t know if there is a footing drain.

I’ll try to find out if these measures were implemented by the current owner. Especially, since you are saying that it is an ongoing problem.

Thanks to you all, and don’t worry, if I put an offer on the house I will have it inspected.


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