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Concrete Porch Lifting Using Polyurethane Foam Injection

Table of Contents


1. What Causes a Concrete Porch to Sink and Become Unlevel?
2. What Is Porch Lifting?
3. How Is Porch Lifting Done?
4. Polyjacking vs. Mudjacking
5. How to Prevent a Concrete Porch From Becoming Unlevel

Looking for information about porch lifting? If so, don’t hit that back button because you’ve landed on the right page. This article will review what causes concrete porches to sink and become uneven, porch lifting and how it’s done, polyjacking vs. mudjacking for lifting porches, and more.

What Causes a Concrete Porch to Sink and Become Unlevel?

There are a few common things that could cause a concrete porch to become unlevel. These include the following:

sinking concrete porch
  • Expansive soil – Expansive soil contains a lot of clay, and this causes it to expand as it soaks up moisture and shrink as it dries out. This swelling and shrinking cycle – which is usually seasonal – creates movement under the porch. Over time, the porch could become unlevel because of this.
  • Erosion-prone soil – Some types of soil are prone to erosion. Over time, the ground underneath the porch can wash away, leaving voids into which the concrete could sink. This is especially common in areas with heavy rainfall or near bodies of water.
  • Improper installation – If the soil underneath the porch wasn’t adequately compacted before installation, the porch is more likely to sink and become unlevel.
  • Seismic events – Anything that causes the ground under the porch to move can cause it to become unlevel.

What Is Porch Lifting?

unlevel concrete patio

Porch lifting involves lifting and leveling an uneven porch by injecting high-density polyurethane foam into the voids beneath the porch. As the foam expands, it lifts and stabilizes the porch. Polyurethane foam injection is also used to level uneven sidewalks, patios, and other concrete slabs that have become unlevel over time.

Porch lifting via polyurethane foam injection is more advanced and cost-effective than mudjacking. (We’ll talk more about mudjacking in just a bit.) Porch lifting is also preferable to replacing the porch.

Porch lifting using polyurethane foam is also fast. The process typically takes only a few hours, so there’s minimal interruption to your daily routine.

How Is Porch Lifting Done?

Step 1: Drill the injection holes

Small, dime-sized holes are drilled into the affected area of the porch.

Step 2: Inject the polyurethane foam under the porch

The polyurethane foam is injected under the porch via the holes. The foam immediately begins to expand and fill the voids under the porch. Gradually, the porch is re-leveled.

Step 3: Patch the holes

After the porch has been lifted, the holes are patched using a compound that closely matches the color of the concrete.

Polyjacking vs. Mudjacking

Compared to mudjacking, polyurethane foam injection (also known as polyjacking) offers a range of advantages that make it a more practical and effective solution for property owners. These include the following:

  • Smaller injection holes – The holes used to inject the mudjacking slurry under a porch are quite a bit larger than those required for polyjacking. As such, there’s a diminished aesthetic with mudjacking as the repair is more visible.
  • Polyurethane foam is lightweight – Because polyurethane foam is incredibly lightweight, it won’t add any additional weight to the soil underneath the slab. This is especially important if the soil is already unstable or poorly compacted, as adding more weight can cause further damage or sinking.
  • Foam won’t wash away – Another advantage of polyurethane foam injection is that the foam won’t wash away or erode over time, unlike the mudjacking slurry. This means the repair will last longer and provide a more reliable solution for property owners.
  • Faster repair – Polyurethane foam injection is also a quicker repair process than traditional mudjacking. Most jobs can be completed in a few hours tops. In contrast, the cement slurry used in mudjacking takes time to cure.

In summary, polyurethane foam injection is superior for repairing concrete slabs affected by settlement. Its smaller injection holes, lightweight properties, long-lasting results, and faster repair times offer a more practical and effective solution than mudjacking.

For more information, see How To Fix An Uneven Sidewalk In Just A Few Hours.

How to Prevent a Concrete Porch From Becoming Unlevel

Fortunately, there are some things you can do to help prevent a concrete porch from becoming unlevel. These include the following:

  • Proper site preparation – It’s essential to adequately compact the soil before laying the slab. This will ensure that the porch is stable and won’t shift over time, causing it to become uneven. It’s also crucial to ensure the soil is free from dead leaves or organic matter that could decompose and create voids beneath the slab.
  • Keep trees away from the porch – Tree roots can grow and shift the soil, causing unevenness and even cracking if planted too close to the slab. Therefore, it’s best to plant trees a safe distance away from a concrete porch.
  • Ensure good drainage – Good drainage around the porch is also essential for preventing unevenness. Water collecting around the porch can erode the soil and cause shifting, resulting in an uneven surface. Therefore, ensuring the surrounding area is graded correctly is essential to encourage water to flow away from the porch. If necessary, a drain tile system should be installed to ensure the soil remains dry.

By taking these preventive measures, you can help ensure that your concrete porch remains even and stable.

If you’re concerned your concrete porch might need lifting, contact us today to schedule an evaluation and receive a repair estimate. We serve all of Northern California.

Steve Egloff

Steve Egloff

Founder of Bay Area Underpinning

Steve is the Founder of Bay Area Underpinning, a foundation repair company serving the San Fransisco Bay Area, California. Bay Area Underpinning was founded in 2005 with the goal of providing a cost-effective, engineered solution to foundation settlement problems with an emphasis on educating customers to make them feel comfortable with the various methods of foundation repair.

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Disclaimer: “Concrete leveling” means the process by which cracked, uneven concrete is stabilized, and in many cases lifted, by means of PolyRenewal™ polyurethane foam. Bay Area Underpinning does not guarantee that PolyRenewal™ can make your concrete perfectly level.

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