How to Repair a Crack in a Concrete Foundation – This Old House

Fixing a fractured foundation with This Old House general contractor Tom Silva. (See below for a shopping list and tools.) Click here to SUBSCRIBE to the official …


Click here for the best online deals on Living Room, Kitchen, Patio, and Bedroom Furniture and decor.

44 Responses to “How to Repair a Crack in a Concrete Foundation – This Old House”

  1. remove the tree

  2. Vivaci Anon says:

    how not to repair a foundation crack…

  3. Dr.Feel Good says:

    Back when I was a teenager we had a floor to ceiling crack like this in the basement of the first house my mom bought after she got divorced. It was covered up (notice I didn't say fixed) in a similar manner. The first time it rained our basement literally filled up with water. This is the kind of dishonest thing you do when you want to sell a house and don't want to spend the time and money to fix something properly.
    I can't believe a show like ask This Old House would show people how to do something in this fashion. I mean it's just idiotic! I learned the hard way as a teenager the proper way to fix this type of thing but this guy doesn't know how?! I'm baffled.

  4. Barry Lab says:

    Foam is not waterproof…and his foam had not cured and he applied the mortar. I wouldnt recommend it if you dont want water coming through that crack. That mortar will crack when the foundation moves a little.

  5. cool work . you are such a pro

  6. tsfcancerman says:

    dumbshits, the crack always stop where the dirt begins (why the hell didnt you do the job properly by digging up the dirt so you can fix the whole crack

  7. Yes he showed perfectly what to do if you want to cover up a real problem and sell the house. Now you paint over it and the poor guy who bought the house has a basement full of water. If anything he only made the problem much worse.

  8. I'm glad that a lot of people see this for what it is, an improper fix. He should know better. That's a cosmetic fix at best and it isn't going to last long, I can tell you that from experience. You can't always believe what you watch on This Old House. There are different ways of fixing that below grade Foundational crack but that ain't one of them. 

  9. Alison Isaac says:

    Can I use this method for the entire outside of my house? ( i think my house is made of concrete blocks ) and i wish to paint the outside, however there are lots of huge ugly holes, not something I can use caulking on.

  10. Polina Kohan says:

    I have a leaking basement without a single crack in the walls or the floor. Wonder if I could "paint" the wall with this cement

  11. nick moore says:

    expandable foam can also crack a wall

  12. Do you know what to use to fill in the crack along where the concrete porch meets the wall bricking?

  13. that is a temporary fix.

  14. Fat Rabbit says:

    lmao "I had a little bit of extra mortar". Not sure why you mixed a whole bag for 1 little crack.

  15. Linda Blais says:

    Can this method be used for retaining walls to? Have a large crack in mine looking for repair options. Not the first time its been repaired not sure how to do it the right way? Not many videos of repairing retaining walls on here

  16. GeoFagus 123 says:

    Isn't this going to crack in the near future?  Water will find its way into the crack overtime. I'm surprised you did it this way.  Epoxy or Poluerethane Injection is the way to go as it fills up the crack completely on the inside.  I believe your way, you are due to re-visiting this crack soon again.

  17. いつもカステラヤンデレちゃん!ですね Σ( ̄。 ̄ノ)ノ wtf

  18. ありがとうさいますfor the help 内ジャンピンポーぽっぽポピーええええええ著ゆはい

  19. water proof says:

    this is a terrible way to fix a crack! maybe 30 years ago this was new technology but there are way better methods.

  20. John Dow says:

    Your kidding, this is the exact reason why you don't have a general contractor touch foundation problems. This is NO FIX!!! A cosmetic fix only, will crack again and make the proper job harder and more expensive. DON"T EVER USE EXPANDING FOAM LIKE THIS!!!

  21. There is a better way of repairing this crack with less work, less product and feeling 100% safe that it will not leak again even if the foundation moved again. You prep the crack with ports that are held with hydraulic cement and the entire crack is also covered with the hydraulic cement. Then you inject through the ports into the crack with a two component urethane with epoxy. You are best to let a professional do it because if you put the wrong product in a crack, especially a hairline crack, you just made the problem a lot worse and much harder to repair. In order a professional can repair it correctly, he has to be able to get the wrong stuff out if that crack first and that is not possible on a fine, hairline crack, which means he will have to bash the hairline crack wide open. Just let the professionals do it.

  22. I like your expertise, I watched your video and I liked the way you get wet the walls for making sand mix bonds with cement, not to many "pros" does it.
    I will continue watching more videos from you.
    thank you very much for making of you your best.

  23. 网中 人 says:

    but what cause the wall crack ?

  24. I always read the comments first so to get a better understanding of what's ahead. Piece of cake, think maybe I will choose different ingredients, add a little of this , a little of that and press dough!  Michigan basement, hate it, fieldstone always crumbling always repairing. If I could afford a contractor and money was not a problem I would dig out the old and pour a new basement.

  25. Sjrick says:

    Tommy adding the acrylic is something ive never seen before. But Tommy knows his stuff for sure.

  26. andy leung says:

    I loved watching this man's video. Although he looked the old man in KFC bucket, but his video didnt make me hungry!!!

    nice job!!

  27. anyone know the best ratio for using the Concrete Bonding Adhesive ?

  28. expanding foam. …not very clever.. you could dry pack it with a dry concrete mix all the way in..or even epoxy concrete resin mix usually used for fixing bolts into masonry.

  29. Tavo Morales says:

    It's gonna crack again for sure

  30. bigbooda011 says:

    I wanna do shit like this

  31. Should or was anything done with that crack on the exterior that extended below ground level?

  32. Thanks for sharing your foundation repair clips.

  33. Chase H. says:

    John you fat piece of shit, go be useless somewhere else.

  34. M. Sebastian says:

    First we must identify why it has crack, subsequently we need to know because of the movement. Then accordingly we can suggest the repair procedure and for the repair we required to wear PPE very important for any kind of relative works.
    The video is good showing how to repair.

  35. ronv11 says:

    hey I got an idea,  come to my house and fix my stuff  too

  36. Concrete foundations move in and out through the seasons (expansion/contractions), they settle down as they get older. Using mortar to surface patch the Crack will only Crack within 5 years. Cracks are moving joints, and it's difficult to bond two different substrates together and have them stay bonded. Since concrete is porous, only certain materials can be used, yet even those materials differ on how far into the pores it gets. Most material, including epoxy, breaks at the bond point. I also noticed he applied the mortar on top of the paint both sides of the Crack. He may as well have just used school glue. It'll be re-cracked within 2 years. .

  37. That looks easy and fast to do. Repairing cracks in the basement as early as possible can prevent major structural problems in your house.

  38. Maxima says:

    Are they using mortar because it is above ground?

  39. Electone_Guy says:

    That crack required epoxy injection and hydraulic cement.

  40. Absolute joke!! This guys sometimes are like clown show!!

  41. Man that was a TON of mortar. Hopefully he has no water seepage problems.

  42. MRrwmac says:

    I know this was just a cosmetic repair and to keep water out. But he didn't talk about the reason for the rack and that it was fixed first. Otherwise be back soon to do again!

  43. Nice job patching… I hope they also solved the settling problem or Tommy will be back patching in another year…

  44. Fantastic segment.  I would love to hear TOH's thoughts on painting the interior of the basement with an impermeable sealer, like DryLok