An unstable subgrade, the soil beneath your home or business can cause your foundation to crack or differentially settle. There are several techniques contractors can use to remedy foundation problems, and using polyurethane foam to stabilize and lift your home is a viable solution. Polyurethane foam leveling can lift sinking foundations, stabilize soil, and fill underground voids left by erosion and excess water, among other applications. Learn what you need to know about polyurethane foam foundation leveling here, including what it is, how it’s injected underneath concrete slabs, and what the benefits are.
Polyurethane foam is a 2-part polymer that’s synthesized from a chemical reaction between polyols and isocyanates. When combined at the correct temperature and pressure, these chemicals expand to form a dense but lightweight foam. Since its creation in the early 1940s, polyurethane foam has been a mainstay of various industries around the world. It has many applications, including cushioning, insulation, packaging, and refrigeration. But in the context of concrete foundation repair, it’s used to raise sinking or settled concrete sidewalks, foundations, and slabs of almost any type.
Poor drainage can cause the soil beneath a foundation to wash away, leaving gaps or voids that make the soil less dense and less stable. Technicians can use polyurethane foam to fill these voids and restore stability to weak and loose subgrade.
When a slab lacks sufficient support and can’t bear the load of the building atop it, it can sink or crack. In these situations, technicians can use polyurethane foam to fill voids in the soil, providing extra support and eliminating movement.
Technicians can also use polyurethane foam to repair seawalls on seaside properties. Over time, seawalls will wear down from constant exposure to tidal action and the chemical attack of the salty seawater. Cracks and breaks in seawalls allow water through, and this water can wash away the soil near the building’s foundation. This results in soil voids and cracks. These cracks and voids can put wall joints in jeopardy and cause them to fail, damaging the structural integrity of the foundation. Polyurethane foam injection can seal leaks in seawalls and fill voids to restabilize loose soil.
Polyurethane foam is specially engineered for use with concrete slabs. It’s powerful and exerts enough pressure to push cracked or shifted concrete back to its original positioning. During the foam leveling process, small, dime-sized holes, roughly 5/8 of an inch, are drilled into a concrete slab. A technician places tapered ports into these holes, then attaches a foam pump or gun to the ports. These pumps are full of polymer liquid, and once injected through the port and slab, the liquid rapidly expands into a foam. The pressure created by this expansion compresses loose soil and raises the concrete slab back into place. Once the slab is filled and lifted, the technician removes the pumps and ports and patches the holes drilled for the ports with grout or concrete. Once patched, the concrete slab will look almost as good as new.
Why use polyurethane foam leveling over comparable foundation repair solutions like mud jacking? Polyurethane foam is a reliable, permanent fix with countless benefits.
Polyurethane foam leveling is a budget-friendly repair method that costs less than half the price of replacing a slab entirely. On average, it costs between $7.00 and $12.00 per pound of foam to lift and level a foundation.
Polyurethane foam is environmentally benign. In its mixed state, after injection, polyurethane foam is inert and non-toxic. It won’t leach corrosive chemicals into the ground and soil.
Polyurethane foam is also hydrophobic, meaning it’s basically waterproof. When exposed to moisture, polyurethane foam remains hard and immobile. This makes it a much sturdier option than slurry or mud, which can wash away in the presence of water. Hydrophobic polyurethanes repel water, similar to the way oil repels water and stays separate when you try to mix them in a glass. When injected, it pushes water out of the area in question as it expands. They also have zero shrinkage after curing.
Polyurethane foam cures quickly, typically taking no longer than 15 minutes after injection to fully dry and harden. Polyurethane hardens within 2–3 minutes.
Polyurethane foam is a synthetic polymer material. In most cases, it provides a long-term solution to foundation settlement or sinking.
Mud jacking slurry weighs roughly 130–150 pounds per cubic foot. The heavy load it places on the soil below the slab can cause the foundation to gradually sink again. Polyurethane foam weighs considerably less at 2.5 to 4 pounds per cubic foot. It’s lightweight and won’t put excessive strain on the soil beneath a foundation.
There’s no need to vacate your home or business during the polyurethane foam injection process. Occupants can continue to live or work normally while a contractor drills into the foundation and injects the foam. Polyurethane foam leveling doesn’t involve any heavy, loud machinery or excavation, and generally only takes a few hours from start to finish.
One of the most important things you should know about polyurethane foam foundation leveling is that it is a versatile repair technique that offers immediate results, but how do you know if it’s right for your home or business? Consulting an experienced contractor can help you determine how to best treat your specific foundation problems.
If you want to learn more about residential and commercial polyurethane foam foundation repair and discuss whether it’s the ideal fix for your property, contact the experts at Foundation Tech. With years of hands-on experience in the foundation repair industry, we have the professional tools and know-how to fix your foundation quickly, correctly, and permanently. We can perform a free inspection on your foundation to pinpoint the cause of your foundation problems. From there, we’ll work with you to formulate a plan that will work for your building and your budget.
If we determine that concrete lifting is necessary, we will use some of the highest-quality and longest-lasting polyurethane lifting foams on the market. We get our geotechnical polyurethanes from HMI and NCFI Geotechnical, whose foams are specially formulated for optimal density, performance, and longevity, so you can be assured our repairs will hold up.