Last year I had an old concrete porch re-done. Long story short, they did not keep it wet when curing, and now the concrete has several cracks in it. I’m concerned about the cracks getting worse and spreading over time, so I am thinking about filling the cracks with some kind of compounds. Any recommendations? I’m thinking a flexible compound like the Sika self leveling concrete fill, but am open to more experienced suggestions.

  • jay2@beehaw.org
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    1 year ago

    The chemical reaction that binds concrete in a matrix takes place after you add the water and continues until you dry it out. Anything you put in the crack will be a temporary fix only. The material will work itself out over time, and you will additionally be trapping a certain amount of moisture in the crack with it. You will now have a concrete pad with a ‘pocket’ and a ‘plug’ made from different materials. Materials that are likely to expand and contract at different rates exposing an opening for moisture and debris at least once through the year.

    You only get (1) chance to successfully pour concrete i’m afraid. Your pad is damaged for all time. The crack will certainly grow from thermal conditions alone. It’s incapable of healing itself. What you need to stave that off is good chemistry for binding and something that expands and contracts at approx. the same rate as the concrete. I’d call the company that poured it. They’ll know what repair product best matches their chemistry. If you put the wrong products in it, it’s going to accelerate the degradation.

    I am a refractory designer, and the company I work for makes several ‘patch’ type products of different chemistries. They all have a use. Temperature, application, chemistry, elevation even. While these do work, they are again only temporary.

    They come in different consistencies. One of those is what we call a plastic. It is very much like a putty until it dries. It does contain some moisture so it will shrink as it dries out. It does not contain as much moisture as a self flowing castable would.

    • gimlithepirate@beehaw.orgOP
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      1 year ago

      Yeah, I called the company and they did a big fat “cracks are normal and we do not guarantee concrete against anything.” Was really frustrating. Found out about half way through the project they just subbed the whole thing out… but reality is around here if you aren’t a contractor willing to do a big order for multiple jobs at once, you aren’t getting a concrete guy. Called 10 different people and these were the only ones that answered…

      Honestly though, I’m not expecting a miracle to “undo” the damage. Just trying to see if there is something that can minimize the amount of damage water seeping through might do.