In our experience, many homeowners with foundation problems want to see foundation repair methods compared. During their research on foundation repair, they come across numerous methods and products, leaving them a little unsure of which route is best. This article will give you a high level overview of the most common foundation repair methods, their differences, and when each one is recommended. But, before we do that, let’s briefly go over why foundations are necessary.
Foundations Support Your Home
Although they’re largely invisible, foundations are essential because they take the load – that’s the weight of the building and everything in it – and transfer it to soil that can support it. In other words, they literally hold up your home. Therefore, foundation problems directly affect a building’s structural integrity. That means if there’s a problem with your home’s foundation, you want to be quick about fixing it because minor foundation issues can often turn into big problems, and big problems are expensive to repair. The good news is that an experienced foundation repair contractor can fix most foundation problems. A foundation replacement is rarely required.
Three Main Types Of Foundations
The deepest foundations are basement foundations. Although in the past, basements were primarily used for storage or as laundry rooms, today, basements are often used as living spaces and have ceilings that are at least 6 feet high.
Crawl Space Foundations
Crawl space foundation walls are usually no more than 4 feet high. That’s just enough room for a homeowner to crawl around underneath the house and get easy access to plumbing, electrical wires, and the central air conditioning system.
A slab-on-grade foundation is a solid concrete slab that sits directly on the ground. While slab-on-grade foundations are usually less expensive than crawl space and basement foundations, you’ll need to break up the concrete to access the pipes if you have a plumbing problem.
Foundation Repair Methods Compared
The four main foundation repair options are helical piers, drilled concrete piers, steel push piers, and crawl space screw jacks. Let’s take a closer look at each one:
Helical piers are used for both new construction projects – especially those requiring a deep foundation system because soil conditions are less than ideal – and for lifting and stabilizing a sinking foundation.
Helical foundation piers are quick to install – because they don’t require heavy excavation – and less expensive than traditional concrete foundation piers. Other names for helical piers include helical piles, screw anchors, screw piles, screw piers, and ground anchors.
Helical piers look something like giant screws and come in a variety of types and sizes. The configuration used depends on the soil type (clay soils require larger helices) and the project’s load requirements. During installation, the piers are turned into the earth until the proper load capacity is reached. This is usually 10-30 feet below ground. However, it could be deeper depending on the requirements.
Drilled Concrete Piers
Drilled concrete foundation piers are often used to repair homes built on hillsides because these structures are susceptible to something called soil creep. Soil creep causes lateral foundation movement and settlement. Signs of lateral movement and/or settlement include sloped floors, cracks in walls, and doors and windows that stick. Other terms for drilled concrete piers include caissons, Cast-In-Drilled-Hole (CIDH) piles, cast-in-situ (DCIS) piles, drilled shafts, and bored piles.
Installing drilled concrete foundation piers involves first drilling a cylindrical shaft deep down into the bedrock. Then, a steel rebar cage is inserted into the shaft, followed by concrete. Once the concrete dries and hardens, the drilled concrete pier is complete.
Heavy-duty steel push piers are probably the most popular piering repair solution for fixing a sinking foundation. The steel piers are driven down into the load-bearing strata using hydraulic pressure along with the weight of the building. The installation process is as follows:
1. The foundation repair contractor attaches steel brackets to the foundation.
2. A hydraulic ram pushes the steel piers through the brackets and into the soil until they reach the load-bearing strata.
3. Hydraulic jacks are then placed on top of the piers, and they lift the building back up.
4. The hydraulic jacks are removed, and the steel piers remain in place to support the structure.
Crawl Space Screw Jacks
Sagging crawl spaces are often repaired using screw jacks. Screw jacks allow the user to adjust floors in hard-to-reach areas with limited access. They’re fast and easy to install and will immediately support the floor’s weight.
In homes without basements, the crawl space is the empty area between the ground and the first floor. Crawl spaces keep the house off the ground and are just big enough to crawl around in. They provide the homeowner with easy access to wiring, plumbing, and central air conditioning.
Over time the support posts in a crawl space can develop problems caused by various things, including expansive soil, drainage issues, screw jacks that weren’t correctly installed, screw jacks that have deteriorated, and an inadequate number of screw jacks. If this starts to happen, you might notice that the floor squeaks, feels spongy when you walk on it, or that your furniture shakes as you walk by.
We can usually repair a sagging crawl space using the existing pier locks and then just removing and replacing the posts or screw jacks.
What Causes Foundation Problems?
No discussion of foundation repair methods compared would be complete without talking about what causes foundation problems:
Soil that hasn’t been adequately compacted before the start of construction. Soil needs to be compacted before construction. If not, it will slowly compact after construction, and this could cause damage to the building.
Expansive clay soils. These are soils that swell when they absorb moisture and then shrink by that same amount when they dry out. Over time, this swelling-shrinking cycle puts stress on a foundation leading to differential settlement.
Heavy excavation next to the foundation. Excavation too close to an existing foundation can cause a loss of support. The effect is similar to what might happen if you dig a hole next to a chair on the beach. Eventually, the chair will probably fall into the hole.
Earthquakes. We probably don’t need to explain this one to you.
Floods. Even slow-moving water has the power to move a foundation.
The repair method used to fix a foundation depends on the type of foundation and the specific problem. When it comes to foundation repair, one size does not fit all. An experienced foundation repair contractor or structural engineer will only recommend a repair solution after a thorough inspection.
Of course, when it comes to foundation trouble, an ounce of prevention is most definitely worth a pound of cure. Foundation trouble can be expensive to fix. Therefore, every homeowner should know both the signs and causes of foundation problems and the basics of foundation repair. Spot foundation problems early, and they’re less expensive to fix.
If you suspect your home has foundation trouble and you’re in our northern California service area, contact us today for a free inspection and estimate.
Steve is the CEO at Bay Area Underpinning, a foundation repair contractor 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.
Northern California can depend on us for expert foundation repair and replacement services such as push piers, polyurethane foam injection, helical piers and more.