How To Lift A Concrete Slab
- First, dime-sized holes are drilled into your concrete. Sometimes, sidewalks can be lifted using a special jack instead of drilling holes.
- Second, the unique polyurethane foam is pumped into the holes until it fills the entire void beneath the slab.
- Lastly, the polyurethane foam will expand under your concrete and harden, lifting up your slab, giving it a stronger foundation to rest on.
Learn more: A Homeowners Guide To Concrete Floor Leveling.
When Should You Lift A Concrete Slab?
- Your slab is sinking due to poor drainage or a sewer break – If water is draining toward your slab, the soil could be washing out from underneath the concrete. This can also happen if your gutters are dropping water too close to your slab or if a sewer line breaks and wastewater begins leaking into the dirt.
- Your slab is sinking into improperly compacted soil – Before any foundation or slab is poured, the dirt underneath must be properly compacted, decreasing the space between soil particles. If this process was skipped or done incorrectly, your slab could sink into the loose soil.
- Your slab is sinking and rising over expansive soil – Soil that contains a lot of clay is what experts call expansive soil. This type of soil will grow when it absorbs water and contract when the soil dries, causing the slab above to rise and fall.
- Your slab is too close to trees and their roots – Roots can make their way underneath your slab, causing the concrete to lift up. Then, when the roots die or absorb all the water in the soil, they could leave behind voids that cause your concrete to sink.
How Much Does Replacing A Concrete Slab Cost?
How Much Does Lifting A Concrete Slab Cost?
- Sidewalks – The cost to lift a sidewalk depends on the width, length, and how much the slab dropped.
- Driveways and patios – The cost to lift a driveway or patio usually costs around $1,500. It just depends on how large the void under the slab is and how much lift is required.
- Interior concrete slabs – The cost to lift an interior concrete slab is one of the most expensive repair types. This is because the usual cause of interior slab sinkage has to do with sewer breaks. Your slab won’t sink right away, though. It will take a large void to sink your six-inch-thick floor. That means that more foam is required to fill the void, thus, increasing the total cost.
Read more: How Much Does Concrete Leveling Cost?
Benefits Of Lifting A Concrete Slab
- It only takes about 15 minutes for the foam to harden and become usable.
- The foam won’t leech chemicals into the soil or grass.
- The foam is lightweight and won’t contribute to any further sinkage.
- Lifting a slab is cheaper than pouring a new slab.
- The foam is waterproof and won’t erode or shift if it comes in contact with water.