The Pros and Cons of Polyurethane Foam Concrete Leveling (Polyjacking)
If you’re tired of looking at your old, settled concrete that’s riddled with trip hazards, professionally leveling the sunken concrete slabs may be just what you need to bring it back to life.
Concrete leveling is a great way to restore concrete for an affordable price, and there are a few different methods for getting the job done right, each with its own advantages and disadvantages.
It can be tricky to decide exactly which route to take when it comes to a concrete leveling repair method, but the concrete leveling company you choose to work with will be able to guide you in the right direction.
It’s important to note, however, that some companies only offer one method of leveling. For this reason, being aware of the options available to you, and their pros and cons, can help you make the best decision on who to work with to fix your settled concrete.
A-1 Concrete Leveling has been in the business of protecting and preserving our customers’ concrete for over thirty years, and in this time we’ve realized that while most repairs are best suited for stone-slurry leveling, sometimes foam-injection leveling will better achieve the desired results. That's why we offer both repair methods.
This article will focus on the pros and cons of the foam-injection concrete leveling method in order for you to be as informed as possible when choosing a concrete leveling company and repair method.
How does foam leveling work?
Before diving into the pros & cons of foam concrete leveling, it’s important to get an idea of how it works.
It is done in essentially the same way as other concrete leveling methods, including A-1’s stone-slurry leveling process, but uses expanding polyurethane foam to lift the slabs.
The foam leveling process is as follows:
- Holes ~⅝ inches in diameter are drilled in the settled slabs.
- The liquid foam is injected through the holes and ends up beneath the slab, where it undergoes a chemical reaction that causes the foam to expand and lift the slab.
- The drill holes are patched.
Pros & Cons of Polyjacking Overview
Foam leveling has some advantages and disadvantages, and they are listed below:
Pros of Foam Leveling
Foam leveling lifts concrete by injecting a polyurethane foam compound underneath the slab. This compound creates a chemical reaction underneath the surface which expands to lift the concrete. When transported, these chemicals have a small footprint, making it easier to carry more material for high-volume jobs, which could reduce repair time.
Because of the small footprint of foam leveling material, there are times when it can be transported easily with portable units. Some spaces are inaccessible by limestone slurry leveling or traditional mud jacking hoses, but portable foam leveling units can be taken almost anywhere.
While this is true, not all foam leveling is done with portable units. Most foam leveling is done with a hose connected to a truck or trailer, as with traditional mud jacking and A-1’s limestone slurry system.
Smaller drill holes
The drill hole sizes of foam leveling are around ⅝ inches and smaller than both traditional mud jacking and the A-1’s stone-slurry leveling system. This is beneficial for areas where a larger or more visible patched hole would be a nuisance.
Cons of Foam Leveling
Foam leveling is usually the most expensive method of concrete leveling. Foam leveling uses synthetic materials and chemicals, which cost more than the natural alternatives. For larger jobs, this higher material cost is a big roadblock.
Doesn't fill voids
Due to the nature of foam, it’s very hard to fill the crevices and space under a sunken concrete slab. What happens is “pancaking,” which is when foam spreads out in a small area, not filling the void, and technicians add layers to the stack until the slab is lifted.
This “pancaking” effect creates weak points where the individual “pancake stacks,” or pillars, hold up an entire slab of concrete, which has a higher chance of cracking where the base is unsupported.
Read more about why voids under concrete should be filled properly.
When technicians stop injecting the foam leveling solution, the lift doesn’t stop. The chemical reaction that takes place after the material is in the void continues to lift, making it easier to overdo the repair when not done correctly by an experienced professional.
Accidents and safety concerns
Unfortunately, accidents can occur with foam leveling. While rare, sometimes the combination of lifting heavy concrete slabs and the foam’s chemical reaction causes a lot of pressure to build up, which can explode and be very dangerous for the leveling crew and nearby surroundings.
Because of the nature of the foam’s chemical reaction, it produces a lot of heat. This heat can actually cause the foam to melt itself, which damages the compressive strength and overall durability of the slab and repair.
Your Next Steps
Professional concrete leveling is an excellent way to bring your settled concrete back to a safe and level position. At the end of the day, the goal of any concrete leveling method is to achieve this, whether it be with foam, mud jacking, or by using a stone slurry method.
Now that you know a little more about the advantages and disadvantages of foam-injection concrete leveling, you’ll be more prepared to decide which company to work with to lift your settled concrete.
If you haven’t already, you can request a free onsite consultation and cost estimate from the A-1 Concrete Leveling team with the link below. Our experts will evaluate your property and advise you on the best method for lifting your settled concrete.
You can continue learning about concrete leveling and other concrete repair and maintenance topics with A-1’s extensive library of resources, called Concrete Academy. Below you will find some related topics:
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