Foundation Repair Methods

There are quite several foundation repair methods today that can be applied to solve the most common foundation problems. The foundation of any building is the most important element of the entire structural system of the building, therefore it is important to ensure nothing goes wrong with your foundation from start to finish of your building project because a compromised foundation can result in a series of problems throughout the life span of your home or building, from landscaping damage, differential settlement to insect intrusion issues.

This article is aimed at providing detailed knowledge on how to use different foundation repair methods to fix any faulty foundation of your home or building.

What is Foundation repair?

Foundation repair is the process of restoring deteriorated or broken foundations. Foundation repair typically includes removing soil, repairing the concrete and rebar, and resealing the foundation. If the foundation is cracked or has other structural problems, foundation repair may also include adding additional support to the foundation.

Foundation repair can be done in two ways: ground stabilization and deep foundation repair. Ground stabilization uses equipment to compress and bind the soil, while deep foundation repair uses heavy machinery to break up and remove the damaged area of the soil.

Basic Signs of Foundation Problems

Cracked walls, bulging floors, doors, and windows that are out of alignment and won’t close are all signs of foundation failure. Most homes built on expansive soils suffer from foundation problems. These problems occur when only a part of a building foundation settles which is known as differential settlement, causing notable cracks and other damage to the superstructure of the building.

This differential settlement is largely caused by differences in the soil moisture content which can lead to serious swelling or shrinkage of the soil during wet or dry seasons respectfully and as well as soil-bearing capacity failure.

It is important to note that settlement cracks are commonly nearly vertical, and should not be confused with cracks that occur when a wall is subjected to bearing capacity failure or lateral movement from soil pressure.

You may be wondering if your home foundation has issues. Normally, every building foundation will settle over time, but issues arise when the settlement is not uniform or extreme.

Here are some common signs of foundation problems you may encounter in your home:

External Signs of Foundation Problems

• Displaced moldings
• Cracked bricks
• Wall rotation
• Separation around  door, window, or walls
• Broken or cracked foundation

Internal Signs of Foundation Problems

• Cracks in floor
• Misaligned doors and windows
• Uneven floors
• Cracked sheetrock

Causes of Foundation Problems

The majority of foundation problems and damages are most times water-related issues. Differences in soil moisture contents cause the soil to either swell or shrink, leading to uniform movement underneath foundation walls.

Most times building foundations are liable for failure or damages due to the following:

• If the area around the foundation has a poor drainage system
• If it was built on expansive clay
• If there are plumbing leakages below the building
• If it was built on poorly compacted fill soils
• If the area has extreme seasonal changes
• if tree roots are growing too close to the building.
• If the environment is prone to earthquakes, floods, or drought.

Soils with high content of clay are usually unstable and more susceptible to differential settlement while those with low clay content are less affected. In some areas, the settlement could be insignificant, and in some other areas, it could be quite pronounced. When your building sits on unstable soils as the foundation base, the differential or upheaval movement is transferred to the foundation and the effect can be seen in both slabs, beams, and the foundation walls.

On the contrary, if the soil under the foundation swells uniformly, there will be no negative effect on the foundation. Foundation problems only occur when only part of the building settles. Then, the differential settlement results in cracks or other damages to the building. Common problems  resulting from foundation differential settlement are:

• Unsightly cracks
• Loss of real estate value
• Damage to the structure
• Equipment malfunctions
• Tripping hazards

Irrespective of the cause, differential settlement can greatly impact the value of your home or building and could even render it unsafe and inhabitable. Any time you see signs of foundation problems, don’t hesitate to get them resolved as fast as possible, because the longer you delay in resolving them, the more your foundation will continue to deteriorate, resulting in further costly or irredeemable damage.

Best Foundation Repair Methods

Most foundation repair methods vary depending on the nature of the soil, climatic conditions, foundation type, and the uniqueness of the problems at hand. The following are some of the best foundation repair methods commonly used in fixing damaged foundations:

1. Sealants and Masonry Patches
2. Piering or Piling
3. Mudjacking
4. Soil Stabilizing
5.  Foundation Underpinning

Sealant and Masonry Patches

Foundation cracks and patches of most building structures can be repaired by patching the cracks and sealing them with a waterproof masonry sealant. The ability to spot and repair cracks early is important in solving your home foundation problem. The most commonly used sealants for minor foundation cracks include the following:

• Hydraulic cement
• Vinyl concrete
• Epoxies
• Silicone
• Polyurethane

The mixture used is dependent on the magnitude of the cracks and other minor or insignificant cracks can be fixed with masonry patches but regular maintenance must be ensured. This is an important foundation repair method.

Piering or Piling Method

The piering or piling method of foundation repair is carried out using a steel or concrete pier to resettle the foundation of a building structure. There is little difference between piering and piling foundation repair methods. Piering is done by excavating the earth strata and then installing the piers to support the foundation while piling is done by directly driving piles into the ground to support the foundation.

Examples of piering or piling commonly used in foundation repair of building structures are concrete-pressed piling, bell-bottom piers, helical steel piers, poured concrete piers, and steel-pressed pilings. These foundation repair methods will do a better job restoring your foundation to its original stable state compared to Slajacking and they are long-term solutions to foundation problems.

Concrete Pressed Piling

Concrete Pressed pilings are effective and durable foundation repair methods used for interior and exterior repairs of foundations. They work better on pier and beam structures as well as concrete slab foundations. Properly installed pressed concrete pilings are driven into the ground to accomplish foundation stability of the structure, usually within a depth of about 12 feet.

Helical Steel Piers

Helical steel piers are also known as anchors, they are usually an ideal foundation repair method for lightweight concrete slabs, piers, and beam foundations; and they are mostly used when the condition of the foundation cannot permit the use of other methods to predetermine the capacity of the load and the entire weight of the structure is transferred to the piers and subsequently to the load-bearing soil underneath. Helical piers can also be used to construct new foundations.

Poured Concrete Piers

This type of foundation repair method is carried out by driving into the ground concrete piers about 10 feet beneath the foundation and it takes about 7 to 14 days for the foundation leveling to be properly cured. The installation period for poured concrete piers is longer compared to pressed concrete pilings since pressed concrete pilings are installed by using precast concrete segments which are already cured before installation.

Bell-bottom Piers

Bell-bottom piers are installed like poured or drilled concrete piers.  The bottom of the pier’s foot is designed to provide a wide area of support to the pier. Just like poured concrete piers, bell bottom piers are constructed by pouring concrete into an excavated hole and placing reinforcement steels into the concrete.

Mudjacking

Mudjacking is a foundation repair method used to lift a concrete foundation undergoing differential settlement or sinking by pumping a grout beneath the foundation slab or beam producing a lifting force to restore the foundation to its original level and stability. This method is also known as slabjacking, concrete lifting, or slab leveling. This is ideal for small portions such as raising steps, decks, porches, walkways,  driveways, and garage floors.

Most times slab foundations undergo differential settlement or tilt when the soil underneath shrinks, swells unevenly, or collapses creating empty spaces beneath the foundation slab.

Mudjacking is carried out by drilling holes through the concrete foundation into the empty spaces below and a solution of natural elements such as sand, cement, gravel, etc. is injected through the holes to fill the empty spaces and then raise the depressed portion of the foundation back to its original level as the solution expands.

Alternatively, Mudjacking can be done by injecting polyurethane through the holes into the foundation concrete to fill the voids beneath instead of using the natural elements, dense and lightweight materials are used instead. These two Mudjacking methods serve the same purpose and work effectively well on smaller portions of the foundation. But, both methods are short-term repairs that will require routine maintenance periodically.

Soil Stabilization

Soil stabilization in foundation repair is the process of making the soil beneath the foundation stiffer and more stable than the previous by transforming the physical properties to increase the strength and the bearing capacity of the soil underneath the foundation. This is usually achieved by chemically treating the soil with lime-based products or other chemicals such as Portland cement due to their pozzolanic reactions to form permanent stable bonds between soil particles thereby creating a solid monolith that decreases the permeability of the soil, which in turn reduces the shrink versus swell potential and harmful effects of freeze versus thaw cycles.

The shrink versus the swell potential of soil is the amount that the soil can change in volume to the moisture content of the soil.  Some soils especially soil with high clay content can expand or shrink as much as ten percent or more. This drastic increase or decrease in volume can easily create enough force that can result in serious damage to a building. This type of foundation repair method is very effective and can last long, with fewer damages to the building structure, and is also environmentally friendly.

Foundation Underpinning

Foundation underpinning is a foundation repair method of supporting or strengthening the foundation of an existing building structure or other structures. This is achieved by reinforcing the existing foundation and strengthening the soil by injecting an expanding filler, or expanding the foundation area so that the structural loads are distributed over a greater surface area. Underpinning is usually required when:

• The existing foundation is no longer strong enough to support the building structure.
• The original usage of the structure has changed.
• A nearby construction necessitates the excavation of soil around the existing foundations.
• The properties of the soil underneath the foundation have changed or were mischaracterized during the analysis.
• The need arises to increase the depth or load capacity of existing foundations to support the additional story.
• Natural causes such as earthquakes, floods, or drought have destabilized the structure, therefore, requiring stabilization of the foundation soils or footings.