When a void under a concrete slab develops, the damage can be costly. It can also reduce a foundation’s integrity, causing cracks in the concrete. These voids can appear underneath driveways, sidewalks, pool decks and other slabs. Professional slab repair specialists know how to fill voids under concrete slabs and restore the quality of the structure of your foundation.
What Causes Voids Under Concrete Slabs?
Voids under concrete slabs are caused by erosion and other soil problems. The following are some of the most common causes why voids form under concrete:
- Erosion: Soil erosion is one of the most common reasons voids form. Erosion occurs when excess water forms around a slab when the water washes away the soil and rocks near the foundation. Two of the most common reasons why erosion occurs under concrete are leaky plumbing and drainage problems.
- Burrowing Insects and Animals: Burrowing critters can contribute to the formation of voids in the soil under a slab or foundation. It can take many months before it can cause significant damage.
- Poor Maintenance Practices: Poor maintenance practices, such as putting off slab repair for later, can make matters worse. They can also contribute to the formation of voids.
- Hydrostatic Pressure: Hydrostatic pressure builds up when water underneath a slab accumulates and doesn’t drain off. This massive pressure buildup can cause the slab level to become uneven and cause cracks later.
- Drought: Dry soil tends to shrink during a drought, which causes voids underneath. If you’re experiencing a drought season in your area, call experts to inspect your home’s foundation and get help fixing erosion under a concrete slab.
- Short Downspouts and Clogged Gutters: Short downspouts and clogged gutters can cause excess water buildup near the slab, leading to soil erosion. Fixing these problems can help prevent excess water from collecting near the slab.
- Soil Settlement: When soil isn’t compacted before foundations are built, the settling soil can cause voids under the concrete. Soil tends to compress unevenly when heavier things are positioned over it. It can cause the foundation to become uneven, which can cause further damage if left unchecked.
- Seasonal Temperatures: The freezing and thawing cycles of the soil can contribute to soil erosion underneath concrete slabs.
How To Fill Voids Under Concrete Slabs
There are three main solutions to fix voids that form underneath foundations and slabs, which include the following:
- Foam Injection: This process is an innovative method for fixing erosion under a concrete slab. It involves the use of polyurethane foam to fill the void that forms underneath a home’s foundation. It’s a high-density foam that reacts and fills the void, expanding and sealing any cracks and other defects.
- Mudjacking: This method uses a cement slurry, also known as mud. You’re not using mud per se, but a mixture of sand and cement, which is used to fill the void underneath. It’s a cost-effective solution, but it has drawbacks. First, the concrete needs time to cure, lasting two to three weeks. Next, there’s no guarantee that the concrete slurry can fill all the void pockets, which can cause problems in the future. Finally, the solidified slurry can make repairing any nearby plumbing more difficult.
- Sectional Repair: Sectional repair requires breaking specific sections of a damaged slab to provide direct access to the underground void. After which, the void is filled with sand, which is compacted and then a cement mixture is poured into the level sand.
The above methods require sufficient training and experience and are best left to professionals. Professionals know how to fill voids under concrete slabs and have the tools and equipment to do the job efficiently.
Expert Concrete Slab and Foundation Repair in DFW
Our seasoned experts at HD Foundations can determine which method is best suited to fill a void that forms under your concrete slab or foundation. Our team can get your slab fixed and stop further cracks from forming. Contact our specialists today by filling out this form and get a free quote.