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Foundation Crack Repair Methods and What to Consider

  
  

Poured concrete foundations crack for a number of reasons.  We recently published an article explaining why.  This post will examine the different types of crack repair options available.  Each method has its pros and cons.    

Before we get caught up in the details of how to fix a crack, let’s take a step back for a moment.  Foundation crack repair should be done by a professional basement waterproofing company - no ifs, ands or buts.  Handymen and plumbers are not usually qualified for the job.  You know what?  Waterproofers have no business hanging drywall or installing hot water tanks!  It really comes down to the experience and expertise of the company that will stand behind the repair. 

Cracks can be sealed from either the interior or exterior of the foundation.  If done right, either way is equally effective.  If there’s a deck or patio in the way, or your basement is unfinished, it’s more common to seal cracks from the interior.  If there’s drywall or paneling up, or an obstruction such as a furnace, an exterior method is often preferred.

Interior Foundation Crack Repair MethodsInterior Foundation Crack Repair

Before the advent of crack injection, the most common way to seal a crack was to “chip it out and patch it”.  What that meant was to take a rotary chipping hammer, chisel out the concrete at the crack location in a “V” shape a few inches deep and then patch it with hydraulic cement.  This usually didn’t hold up very long because the crack wasn’t filled all the way to the outside soil.  To make matters worse, hydraulic cement is not a very strong or durable product. 

Crack injection is now the preferred method of interior foundation crack repair.  You might have heard of “Epoxy Injection” or “Urethane Injection”.  The process consists of sealing the crack on its inside face with an Epoxy paste and injecting a resin (Epoxy or Urethane) which fills the entire crack all the way to the outside soil.  We typically prefer using Urethanes because they remain flexible and are considered by most to be more effective for waterproofing.  We used epoxies years ago, but found they were better suited for structural problems.

Exterior Foundation Crack Repair MethodsExterior Foundation Crack Repair

Some homeowners still believe the best way to fix a foundation wall crack is from the exterior.  I’ve found many are from an older generation, before crack injection was brought to the market.  Repairing cracks from the exterior is still a great way to go, especially when compared to a hydraulic cement patch on the exterior. 

In order to properly seal a crack, the earth must be removed along the wall to expose the crack from the top of the wall all the way down to the footing.  Some companies will take out a shovel, and dig a hole big enough to get a man inside it.  We prefer using a post hole digger – which is a tool most commonly used to dig fence posts.  The hole we core is typically about 8 to 12 inches in diameter.  It is a much less disruptive process to your landscaping.  We never saw the point in making a three foot wide hole to seal a crack which is typically not much wider than a quarter inch.  Once the crack is fully exposed from top to bottom, the hole is filled with granular clay which forms an impermeable water barrier. 

Again, we really like to stress that both interior and exterior crack repair solutions are viable options.  It really comes down to the obstructions. 

We speak from experience; we’ve probably repaired more foundation cracks than anyone in the country.  If you have a crack that is leaking, give us a call, or better yet schedule your consultation online and save 10%.  Or pose your question below.  We love chatting about cracks. 

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Comments

I have a small crack in the foundation that runs about 6 ft from below the basement window to the floor. I have dug a whole on the outside and was going to use tar with the roofing fabric to repair. I have a tar that has fiber in it but it is not mastic. Does it need to be mastic and does a heavy visqueen work better than roofing fabric? Also if I repair the outside should I still need to fill the crack on the interior?
Posted @ Tuesday, April 24, 2012 1:53 PM by Eric westrick
Hi Eric- 
 
Thanks for dropping in. You definitely don't want to use visqueen. Roofing tar really isn't intended for below ground use. If you already have the hole dug and the entire crack exposed, it's best to use a foundation waterproofing membrane which are best for below ground applications. Please let us know if we can be of further assistance.
Posted @ Tuesday, April 24, 2012 5:50 PM by Matthew Stock
Thanks for the clear instructions on how to repair cracks. Would it be alright to do minor repairs on our own though, or is it totally necessary to hire professionals for repairing interior cracks?
Posted @ Wednesday, May 09, 2012 3:32 PM by Roof Membrane
Hello @ Roof Membrane- 
 
 
 
Thanks for dropping in. 
 
 
 
I would advise against it and go with a pro. Here's a blog explaining why: 
 
 
 
http://info.seepage.com/chicago-basement-waterproofing-blog/bid/120750/Why-a-Handyman-Should-Not-Do-Your-Foundat
Posted @ Wednesday, May 09, 2012 10:41 PM by Matthew Stock
Hi - I'm in Ontario have a hairline leaking crack and thought I'd try your solution. I can buy fine or granular 3/8 clay. whats better? do you make a slurry or just dry pour it in. Do you fill the hole right to the top with the clay? Thanks for any info I hope this works, I just get a small trickle after alot of rain. Jeff
Posted @ Saturday, August 18, 2012 11:37 AM by Jeff Campbell
Hi Jeff- 
 
Both fine or granular clay will work. It should be poured in dry. The top 6" should be filled with dirt as you don't want to leave the bentonite exposed (which should be poured in dry). You can just tar the crack at the top where the dirt starts. Hope that answers your questions. Happy digging! 
 
 
Posted @ Saturday, August 18, 2012 1:22 PM by Matthew Stock
Great article. I shared it for the folks in the Philadelphia area that need foundation repair. For more information on foundation repair, you may visit http://www.ebasementwaterproofing.com/services_foundation_repair.php
Posted @ Wednesday, August 22, 2012 8:34 PM by eBasement
Hi- i have corner wall cracks (1cm)that show from the exterior to interior (vice-versa). what should i use to fill and patch the cracks?
Posted @ Wednesday, November 07, 2012 5:49 AM by Khotso
Hello, There is a rather wide crack in my foundation. An addition to the house was made and it is near that addition. There is no water showing in the basement but there is a mildewy smell. Do you recommend an inside injection - is this good for a crack that is wider than usual? Thank you for your advice!
Posted @ Friday, November 09, 2012 8:16 AM by cathy
I have a crack in my concrete foundation wall that was previous injected with epoxy. It has started to leak again. Is there a product that can be used in this application? I can still see the epoxy that was injected and the water is coming in between the epoxy and the concrete. Thank you in adance.
Posted @ Tuesday, November 13, 2012 1:06 PM by Danny Kapp
Hello, with ref to my previous post, yesterday the crack was injected from the inside by a professional. He said it was a cold-joint crack where the addition met the original portion of the building. It was sizeable but the results were very good. I was also told there was no evidence of previous water infiltration, which was very good news indeed!
Posted @ Thursday, November 15, 2012 8:08 AM by cathy
I should have mentioned in my last post that the injection was polyurethane. Another company I had called were planning to use epoxy so it is all very confusing which is best.
Posted @ Thursday, November 15, 2012 8:11 AM by cathy
Danny: Thanks for your question. That's one of the problems with epoxy injection -- it sets up rigid and often cracks with the slightest movement of the wall. 
 
Unfortunately, the crack cannot be re-injected without chipping out the epoxy and starting over. I suggest that you have it injected with expanding urethane this time to avoid a repeat occurrence. 
 
If you're in the Chicago/Milwaukee/NW Indiana area, we'll be glad to give you a free estimate.
Posted @ Thursday, November 15, 2012 8:16 AM by Warren Hazelton
Cathy: Polyurethane was definitely the right choice -- see the question above from Danny. 
 
There is still a good chance that the crack may be structural. Please keep an eye on it and if you see any further cracking, consult a structural engineer or foundation repair expert.
Posted @ Thursday, November 15, 2012 8:19 AM by Warren Hazelton
hi,i have a foundation of part cement then previous decded to dig from inside and add another part of the basement to the rest of the house , well he quit because of large rocks uhderneight the rest of the house. where the old fountation ends and the rocks begin is a steady stream of water-how can i patch that and keep the water out, i've tried hydrulic cement but it just floats away where the water is--help
Posted @ Saturday, January 05, 2013 12:04 PM by mike madigan
Maddy: It's hard to answer your question without seeing the problem. If the previous owner broke though the existing wall to attempt to enlarge the basement, that break will have to be repaired by a professional. 
 
If you want to e-mail some photos, maybe we can give you better advice.
Posted @ Monday, January 07, 2013 12:09 PM by Warren Hazelton
What would be the ballpark cost for an interior crack repair? I have a hairline crack in basement foundation about 4-feet long that stops about one foot from basement floor and allows water to seep in after heavy rains. Basement area where crack is located is unfinished.
Posted @ Tuesday, January 15, 2013 4:30 PM by Glen B.
Thanks for great information. I have searched locally (Google) in the Chicago area for sodium bentonite without success. I did find, however, cat litter made from 100% sodium bentonite. By chance is this the same product for pouring in around a vertical crack. 
 
Thanks
Posted @ Sunday, February 10, 2013 6:57 PM by Norm
I have the same problem as the above poster. The crack in the foundation had epoxy blown into the crack years ago and you can still see it, but now it's leaking again, so what can it be fixed now?
Posted @ Monday, February 11, 2013 12:36 PM by corinne walker
Corrine: 
 
That is the problem with epoxy injection -- it cracks with even small shifts or settling of your foundation. These cracks can be repaired by injecting them with expanding polyurethane that will remain flexible and won't crack again. If you're located in Chicago, Milwaukee or NW Indiana, please contact us. If not, make sure you find a basement waterproofing company that uses urethane; some still use epoxy.
Posted @ Monday, February 11, 2013 12:44 PM by Warren Hazelton
Corrine, what I did on mine was drill a small hole every 6" down the full length of the crack between the epoxy and the concrete. I then applied the surface ports over the holes that I drilled. I then followed the normal instructions for the application of the urethane injection. We have since had several hard rains and knock on wood I haven't seen any water leakage.
Posted @ Tuesday, February 12, 2013 6:10 AM by Danny Kapp
Hi we have recently went under contract to purchase our first home, we were a bit scared due to some major crack work in the basement wall. The previous owners just a month or so prior had a structure engineer come out to survey and then had a foundation company do the work that the engineer had requested. This involved grading the ground around the wall having new draining put in and then they did that epoxy/or something (these plastic tubes sticking from wall that squired stuff in) filler stuff. It all looked good, and like the problem had been taken care of. We just had a massive snow about a week ago and went to check on the house yesterday there was a small amount of water leaking from two different locations. One of them wasn't even from the original work? more like a concrete seam, like the water wanted to find a new route? I am getting nervous. THe work is under warranty but is there more we should ask to be done, some type of wall tar or something? any info would help.
Posted @ Sunday, March 10, 2013 11:48 AM by candice
I have gotten 3 estimates to fix a crack in my basement wall that runs from bottom to top and leaks when it rains, plus you can see the crack from outside at the base of the house. Out of these 3, which do you think is the best method: (1) drill holes along the crack inside and inject urethane. (2) Cleaning out the crack, covering it, and cutting the floor to allow drainage. (3) Injecting Bentonite along the crack from outside. Which would you recommend. These are tough choices for me. Sincere thanks for any advice.
Posted @ Friday, March 15, 2013 12:07 PM by Kathy
Hi I have a hairline crack 1cm wide on one of my walls in my basement. When it rains a lot/or hard enough it begins to leak. Of course my homeowners insurance does not cover,they said it was considered a flood,had to laugh at that one...any way the wall that it is on exterior side is covered by our enclosed front porth that runs the width of our home. You can get under there crawl space maybe 2.5 feet high? what would you recommend ? Sealing the interior first to see if that works first?Doing both? and again what is best to seal this hairline crack the inside? Hope this makes sense:) Any information any one has would be great. Thanks in advance. Chantell
Posted @ Thursday, April 11, 2013 9:05 AM by Chantell Williams
Chantell: If the crack is only 1 cm wide, you should able to stop it from leaking by having a professional inject it with expanding polyurethane from the inside. That should seal the crack permanently without having to disturb the exterior. 
 
Just so you know, it is typical that homeowner's insurance does not cover basement leaks because they are not considered "catastrophic losses," that is, they aren't caused by a single event. Usually, water damage is only covered when it is above ground.
Posted @ Thursday, April 11, 2013 9:30 AM by Warren Hazelton
I am seeing responses to the post after mine, and I hope I have not missed something, but could you comment on my post from March 15? I sure would appreciate any advice. Sincere thanks - Kathy
Posted @ Thursday, April 11, 2013 9:39 AM by Kathy
Kathy: Sorry. I missed your post until today and thought I might be too late to do you any good. 
 
I assume that the crack in your wall has been evaluated by someone who knows structural damage when they see it. You don't mention how wide the crack is but if it's more than 1/8th of an inch, that's a possibility. 
 
If it just needs to be filled, the best approach is to inject it with urethane. That will fill and seal it all the way to the outside and will remain flexible against future foundation movement. 
 
Sodium bentonite works, too, but it should be applied in a small excavation next to the wall rather than being injected. It won't however, do anything to the portion of the crack that's above grade; the urethane is a better choice. 
 
As far as #2 goes, just don't -- unless you like dampness and humidity. 
 
Please email me directly if you have any other questions: whazelton@seepage.com
Posted @ Thursday, April 11, 2013 11:46 AM by Warren Hazelton
I reside in a townhouse and the basement wall which is blocks is cracking in the mortar cracks, My neighbors have the same problem. It is 24 years old and we did not have this 6 years ago when we both purchazsed the townhouse. I would like to know the least expensive whay to have this permanently fixed as I want to sell. We had someone come in and measure and they stated that it was normal settling. Is this so? Thanks
Posted @ Saturday, April 13, 2013 7:29 PM by lonna fenaughty
Ionna: Before I can advise you on any repair methods, I need to know if the wall is bulging or bowing inward or just showing cracks in the mortar joints. Also, it would be helpful to know if you are getting water seepage through the cracks. 
 
One thing I can tell you that it is not "normal settling" when mortar joints crack. In a 24-year-old home there is no such thing as "normal settling."
Posted @ Tuesday, April 16, 2013 8:12 AM by Warren Hazelton
First, I wanted to thank you for the service you provide online for those who are too far to use your company! 
We have recently bought a house and discovered cracks in the basement that leak with heavy rain. A few of the cracks are exposed, but the main culprit,where the exterior wall has a corner & there is a large crack or two, is covered with sheetrock. (We finished that when we moved in in order to have a bathroom in the basement.) We were advised to put a membrane along the outside of the concrete wall; would you agree with this? Any help would be appreciated! 
Posted @ Friday, April 19, 2013 1:33 PM by Deann
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