Have you noticed, especially after recent heavy rains, water ponding on your patio, driveway, or other concrete slabs? While there may be no visible cracks, somehow the concrete has settled or sunk, and water simply accumulates there, unable to run off. Besides being inconvenient and unsightly, it presents a safety hazard for your family and friends who walk across the concrete surface. The question is, “What should you do about it?”
If there is no obvious crack or hole in the concrete which allows water to seep onto its surface, water ponding often is caused by incorrect grading of the concrete slab from the time it was poured. It is critical that the concrete is set up with a slight slope away from the house and foundation so that the water has an opportunity to run off into the yard, drain, or drainage ditch. If not, water will simply remain pooled on top of the concrete.
Frequently, natural settlement of the soil through the passage of time will cause the concrete to sink in such a way that water is unable to run off. For that reason, builders often recommend not building concrete patios until the soil around a new construction has had adequate time to settle.
Most often, water ponding is due to changes in the soil beneath the concrete slab. After cycles of wet and dry or freezing and thawing, the soil beneath the concrete may become unstable and develop pockets or holes. Eventually, the soil will not be able to support the concrete, and the concrete will actually sink into the holes beneath it. Naturally, after a heavy rain, water will pool into the lowest sections of the concrete.
There are basically three choices regarding what to do to repair a concrete slab that has water ponding. You can grind it, replace it, or raise it. The following information explains the three options along with their advantages and disadvantages. Hopefully, it will help you determine the best option for your sinking concrete.
Grinding involves milling off a portion of the good concrete slab so it matches the sunken slab. While it may eliminate a trip hazard, it does not solve the underlying problem and offers only a short-term solution.
While some companies are willing to grind off a layer of a good slab to fix a trip hazard, it doesn’t solve the underlying problem: what caused the slab to settle in the first place? Unfortunately, whatever caused the problem in the first place will simply return, usually within a year. If the company grinds the concrete a year later, the problem will simply occur the next year, and so on.
The bottom line is that grinding a good section of concrete never solves the root of the settling problem. It’s the underlying soil that caused the settling in the first place. After several years have gone by, the concrete will simply become too thin and crack, requiring the entire slab to be replaced. Besides paying for the annual grinding, the homeowner is now faced with the expensive option of replacing the concrete.
If you are extremely tight on funds, grinding could be a solution for you. Keep in mind that it is a short-term fix that eventually will require replacement of 2 or more concrete slabs.
Replacement involves tearing out the old concrete and building a new concrete slab in the same spot. It is very costly and disruptive and could lead to further problems in other parts of the structure.
Replacing a concrete slab is the most expensive method to eliminate a tripping hazard. Not only will you have the cost to tear out and remove the old concrete, but you will also need to pay for the grading, materials, and labor for the new slab.
Concrete replacement is also extremely disruptive. Besides creating loud noises with the jack-hammers, removing the old concrete creates a great deal of dust and mess. It also tears up the soil and landscaping surrounding the slab. Bringing in a cement truck to pour the concrete can also tear up the yard and make a mess. Also, it takes a long time for the concrete to cure before you can use it again.
Finally, concrete removal and replacement could damage other parts of the structure while the concrete slab is removed and the soil is disrupted. If they are not properly braced, adjacent decks, porches, crawl spaces, drainage systems, and the foundation itself could be damaged during the process, leading to an even greater expense.
Concrete raising involves pumping either a concrete grout (mudjacking) or a polyurethane solution (polyjacking) through holes in the concrete slab to fill the voids underneath and raise the concrete.
Mudjacking lifts and raises concrete slabs by pumping sand-based grout beneath it. The force of the pump pushes the slab back into place. Unfortunately, it is very messy, takes a long time to dry, and isn’t a permanent solution because the conditions that caused the soil to shift under the slab still exist. It will only be a matter of time before the slab has slipped again.
Polyjacking, sometimes called foamjacking, lifts and levels slab foundations through injecting a high-density polyurethane foam beneath the slab through small holes drilled in the concrete. The foam expands and gently lifts the entire slab back into place.
Polyjacking has many advantages over mudjacking and other methods of concrete repair:
Initially, polyjacking is more expensive than either grinding or mudjacking. In the long-run, however, it is more cost-effective because it is extremely long-lasting and will not need to be redone in a year or two. Also, polyjacking not only stabilizes the soil, but it also strengthens it, so that the concrete is far less likely to crack or need to be replaced.
Polyjacking.com can raise your sunken slab to its proper level within an hour, allow you to use the slab almost immediately without waiting for concrete to cure, and provide a long-term solution to your problem. Contact us today for a free estimate!