Strengthening the Foundations of an Existing Home
The foundation of a home isn’t something many property owners think about until there’s a problem. However, there are solid reasons to consider investing in reinforcing the foundation long before that happens. Floods, wind forces, and general soil erosion can all be key concerns for property owners over time. Luckily, there are solutions available for most situations to prevent catastrophic failures.
Photo credit: Visitor7.
Why Should Foundations Be Strengthened?
The foundation of a home is what everything else rests on. It’s supposed to be the durable base that can withstand anything. Yet, changes in the soil under it (for example, caused by floods) or the weight above it (e.g. by adding a story addition) can create shifts in the foundation. Sometimes, the foundation itself cannot handle those shifts and breaks occur.
In Houston, we have to deal with clay-rich gumbo soil which is sensitive to changes in water content. When the soil gets wet it expands upwards, applying pressure on the concrete slab above. When the soil dries out the soil shrinks, leaving the concrete base unsupported.
When shifts and breaks happen, it can compromise the integrity of the entire home. That’s never a good thing, and it’s a costly repair.
The good news for property owners is that most existing structures can be reinforced. There are various methods to doing so. However, it’s best for a structural engineer or residential contractor to provide specific recommendations for your home. The bottom line is – if your foundation has problems, it can often be fixed.
Signs of Damaged Foundations Requiring Improvements
It can be a challenge, in some cases, to see the pressure and force that a foundation is under. Most people never think twice about the changes they make to the structure, such as adding new walls, changing the layout, room additions, or managing moisture buildup. Yet, there are typically tell-tale signs that the foundation needs repairs. Here are some of them.
Perhaps the most common sign of a damaged foundation is the development of cracks. Visible cracks typically occur after hidden ones, meaning the problem is likely more extensive than it seems. If there is any crumbling of the exterior walls, this is a key concern. Inside the home, a basement may show signs of hairline fractures and visible damage. These are all concerns.
Warped Ceilings and Walls
The walls within the home may provide more insight into what’s occurring underneath. If there is warping, such as the walls or the ceiling is no longer flush and flat, this can indicate a house shifting has occurred. It can also be found by looking at the corners of the rooms of the home. They may no longer match well. If the corners, molding, joints, and ceiling are no longer flush, that can be a concern.
Many times, foundation damage stems from water. If water does not drain properly away from the structure, this can create a damaged foundation. Concrete foundations can only take so much moisture buildup before they begin to crumble.
A few other structural signs also need to be considered. Sloping stairs, windows that are no longer square, floors that are no longer level, and doors that do not align properly are also signs. You may notice these when objects roll on the floor in one direction, or the doors do not stay closed tightly.
How Can Foundations Be Strengthened?
If you have these signs, it may be time to consider a variety of solutions that may help repair them. The right method for your residential structure depends on the specifics of your situation. Here are some commonly used methods.
This method is used to either increase the depth of the foundation or to repair the foundation if it has significant damage. If the building has cracks in it, especially those that are wider than ¼ of an inch and visible, this may be the right method. There are several types of underpinning available.
Mass Pour: This method is the most commonly used. The foundation is excavated in sections to below the footing. Concrete is placed into each pit exposed. This is repeated until the area is completely underpinned.
Screw Piles and Brackets: A second form of underpinning involves the use of screw piles and brackets, which can be done by hand or with a smaller excavator. It is a faster option with a reduced amount of vibrations that could cause damage to other areas of the property.
Pile and Beam: This method of underpinning involves the installation of a mini-pile on either side of the walls impacted. Then, all brickwork is removed under the wall, and then reinforced concrete is placed in this area. This is beneficial in situations where access is limited or when there is a high load capacity.
Piled Raft: This method is used when the entire building needs to be underpinned, which is not that common. If the foundation is too deep for other methods or if the soil is just too hard, this method may be used. Here, piles are located at various locations, and then pockets are broken out under the footing. Then, the process involves placing reinforced needle beams to hold the weight of the wall.
2. Jacketing of Foundations
Another method you may hear about is jacketing of foundations. This method is used when there are columns that require strengthening. This is a common need when adding additional load to the wall, such as through expansions. In order to ensure the wall is strong enough to accommodate this, it may be necessary to widen or add more strength to the foundation that is already present. To do this, the team constructs a concrete jacket that is added to the existing footings of the building.
Mudjacking doesn’t quite use mud, but it is a method for improving the foundation of smaller footprint spaces. It is often used for steps, small concrete surfaces, and porches. Cement and other materials are injected into small holes that have been placed into the concrete. The material expands, which helps to raise the slab that is no longer aligned into place.
4. House Lifting and Leveling
To avoid flood damage, it may be necessary to use house lifting. This is never a simple process, but it can involve the use of a hydraulic jack that is placed under the home to lift it. Sometimes called building jacketing, this process removes the actual structure of the building from the foundation itself and raises it with screw jacks. It can help when there is a need to relocate the structure or to improve the foundation underneath it.
In all situations, contractors must consider things like the condition of the concrete slab and the rest of the home. They also need to consider the actual level of damage and the type of soil around it. A customized plan is nearly always best.
The Added Benefits of Foundation Work to Reinforce a Home
There’s no doubt the main benefit of shoring up the foundation of a structure is to make it safer. However, there are other benefits, too. In some situations, this helps ensure that the property remains valuable and one you can sell. Without the repairs, it may be hard to find a buyer. More so, a foundation with significant damage may also make the home harder to insure.
Residential foundation repair isn’t something to put off. If you believe there’s a concern with your structure, turn to an engineer or contractor to determine which solutions are best for your needs.