Sinking or cracked concrete slab

Posted Mar 17, 2021 in Concrete Raising

A sink­ing slab (also known as sink­ing con­crete) is always worth fix­ing, whether it’s locat­ed in your base­ment, garage, dri­ve­way or patio. A sim­ple crack in a con­crete slab isn’t nec­es­sar­i­ly a prob­lem. Cracks are even sup­posed to occur along con­trol” joints such as those built into a sidewalk.

When a con­crete slab cracks and sinks, this indi­cates a more seri­ous struc­tur­al issue. In addi­tion to look­ing bad, a sink­ing slab can cre­ate an uneven sur­face that pos­es a safe­ty haz­ard. Instead of hop­ing the prob­lem will go away or wor­ry­ing about the poten­tial for injuries and even law­suits, it’s smart to fix a sunken slab.

What caus­es a slab to sink?

When all or part of a slab sinks, it’s usu­al­ly due to one of two pos­si­ble con­di­tions. First off, the soil beneath the slab may have char­ac­ter­is­tics that make it com­press eas­i­ly. In oth­er words, the weight of the slab push­es down on the soil, caus­ing the slab to sink. Soil ero­sion can be anoth­er cause of a sink­ing slab. Heavy water flow some­times wash­es away the soil beneath a slab, which then sinks into the result­ing hole or void.

Some con­trac­tors rec­om­mend repair­ing a sink­ing slab by demol­ish­ing the dam­aged area and pour­ing new con­crete. There are sev­er­al prob­lems with this repair strat­e­gy. For starters, it’s expen­sive and the repair will take at least sev­er­al days because the fresh con­crete must hard­en and cure before the slab can be used again. But even more impor­tant­ly, if weak soil caused the slab to sink, the soil may com­press again under the weight of the new slab. A short­cut repair –adding more con­crete to lev­el or even out the slab — impos­es, even more, weight on the soil, increas­ing the risk of sink­ing in the future.

Patio 2 Before
Patio 2 After

Polyurethane Foam Con­crete Rais­ing can repair your sink­ing slab quick­ly & effectively.

What if you could raise a cracked slab back to its prop­er lev­el in less than an hour, with no down” time wait­ing for new con­crete or mor­tar to cure? This fast, afford­able way to repair a con­crete slab. The process involves drilling one or more small holes in the sunken area of the slab, then inject­ing an expand­ing geot­ech­ni­cal” foam beneath the slab.

As the foam expands due to a chem­i­cal reac­tion, it push­es the slab back towards its orig­i­nal posi­tion. Our team can gauge the expand­ing action of the foam, con­trol­ling the injec­tion process for just the right degree of slab-rais­ing action.

Because the inject­ed poly­mer mate­r­i­al cures quick­ly, the restored slab can return to its full weight-bear­ing func­tion with­in a mat­ter of min­utes. Slab repair cost by using polyurethane method also costs far less than replac­ing the con­crete slab altogether.

Fam­i­ly Water­proof­ing Solu­tions can raise, lev­el, and sta­bi­lize your con­crete slabs for an afford­able price. One of the biggest advan­tages of using polyurethane foam is that it fills the voids while also adding sta­bil­i­ty. Call our team at (708) 330‑4466 for more infor­ma­tion on fix­ing that sink­ing or cracked con­crete slab today, or sched­ule an online FREE esti­mate.

About the Author

Maria Kirchner, founder of Family Waterproofing, is a waterproofing expert with extensive hands-on experience in basement waterproofing, concrete raising, and moisture prevention. Passionate about staying ahead through annual training, she shares practical tips on her blog to empower homeowners—like tackling sinking slabs with polyurethane foam for quick, cost-effective fixes. Her customer-first approach has earned hundreds of 5-star reviews, helping families protect their homes with confidence. Connect with Maria for personalised advice: Contact Us.

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  • Thank you for final­ly get­ting rid of my flood­ing prob­lem. I had almost resigned myself to liv­ing with the Black Lagoon in my base­ment. You were able to iden­ti­fy the real prob­lem with my leak by using some empir­i­cal evi­dence rather than guess­ing and charg­ing me for fan­tas­ti­cal projects. Above all, you talked to me as if l am an intel­li­gent per­son instead of the lit­tle lady” who needs her hus­band to make a deci­sion. Final­ly, the extent and care of your pro­pos­al, with its exten­sive pic­tures, con­vinced me that you are an hon­est bro­ker. My base­ment stayed dry despite the recent tor­ren­tial rains. I would be hap­py to rec­om­mend your work.

    Paris
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    Ed
  • We con­tract­ed Fam­i­ly Water­proof­ing Solu­tions for exte­ri­or wall seal­ing and foun­da­tion crack repair ser­vices. Ken was very thor­ough in explain­ing the work that would be done, and his crew did a great job. This busi­ness was a plea­sure to work with.

    Stacie T.
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    William