There are many reasons why land under or around your house could be caving in. But if you think your house is sinking, act now to prevent any complicated and costly structural damage.
In this article, we share the issues of a sinking foundation, including the warning signs and recommended repairs.
How Serious Is a Sinking Foundation?
No homeowner wants to spend money and time on foundation repair. But house foundation issues can create a lot of stress and pressure on your home’s wall, resulting in cracks, leaks, and even structural damage. This can affect you and your family’s safety plus reduce the value of your home.
Common Causes of Sinking Homes
A sinking foundation can be the result of any (or all) of the below causes.
Common subsiding causes
- Foundation settlement
- Clay shrinkage
- Water escaping
- Underground mines
- Drought
- Your home’s age
- Trees
Foundation Settlement
There are many factors that can cause foundation settlement, such as climate, soil condition, and age. Every home’s structure will settle slightly — especially with new homes — but the severity of settlement depends on the foundation’s design and the type of soil.
Furthermore, unstable soil can change over time, which might mean that it can no longer support a home’s structure, resulting in foundation sinking
Clay Shrinkage
Clay soil shrinking is a very common cause of sinking land. Since clay consists of around 30% water, it can dry out and absorb nearby water sources, especially if the weather is hot. This decreases the volume of soil, which leaves your home more susceptible to subsiding.
Water Escaping
Leaking pipes can cause water to escape, reducing the volume of soil beneath, and potentially causing your home to sink. This water escape can also cause soil underneath to soften, making the foundation for your home softer and weaker.
Underground Mines
Buildings can sometimes collapse due to underground mines. Fortunately, some insurers will compensate you for this foundation damage, and it might be possible to receive a recovery payout to compensate for the damages.
However, there are some situations where homeowners will be held responsible for the loss or damage caused by underground mines.
Drought
If you live in an area where drought is common, the home’s foundation might be more prone to shrinking due to lack of moisture.
Your Home’s Age
The older your home, the bigger the chance is of it sinking. However, it’s not all bad for older homes because they’re usually built from lime mortar and bricks, making them less likely to damage from the ground beneath them shifting.
Trees
Trees planted near a house are a common cause of a house sinking because their roots withdraw moisture from the surrounding soil. This means that there’s less soil to support a foundation.
Warning Signs of Sinking Homes and Inspection Guide
Warning signs of settlement issues
- Sinking or uneven floors
- Cracks in walls
- Doors and window frames separating
- Skirting boards separating
- Water pooling around the property
Below are some common foundation problems that you can recognize in the early stages.
Sinking or Uneven Floors
It’s fairly common to experience sloping floors under your home if your foundation is sinking.
Cracks in Walls
Look for any cracks in the walls or floors (vertical or horizontal). These floor or wall cracks are usually a result of a house sinking. In the early stages, they aren’t always visible, but you can feel the gaps if you place your finger over the area.
Window and Door Frames Jamming
Have you noticed that doors and windows don’t open or close as easily as beforehand? Or perhaps you’ve discovered gaping holes between the frames and the door/window. This is usually caused by cracks surrounding the joints.
Skirting Boards Separating
You’ll notice visible gaps between skirting boards and the wall.
Water Pooling Around Your Home
Waterproofing your home prevents water from pooling on the soil, which can then soften it, causing your home to sink.
What to Do If Your House Is Sinking
If you think your home might be subsiding, don’t ignore the problem. Contact a structural engineer immediately to prevent the issue from worsening. The sooner you take the step to make repairs, the easier everything will be to deal with.
A professional will assess your home’s foundation to check for any issues before they confirm if it’s caving in. It might take several inspections before they determine the issue, and the entire process — including repairs — can take up to a year, depending on the severity. That’s why the earlier you start, the smoother and cheaper the process will be.
Ways to Repair a Sinking Home & Cost
Here are some ways to repair a sinking home before the problem worsens.
| Method | Cost |
| Sealants and masonry patches | Around $37 |
| Slab jacking | $511–$1,790 per $3–$6 square foot |
| Helical steel piers | $30 per foot |
| Steel piers | $700–$1,600 per pier |
| Concrete piers | $1.50–$24 per linear foot |
Sealants and Masonry Patches
This is a common method to patch up cracks in a foundation and to prevent any further damage. Vinyl, concrete, polyurethane, silicone, and cement are just some materials used to seal cracks, but the type depends on how severe the crack is.
Cost
Around $37
Slab Jacking
This method includes companies drilling holes through the foundation to the sunken space underneath. They then fill the holes with soil or cement, or you can use a polyurethane injection.
You might need to repeat slab jacking every few years, depending on whether new cracks form.
Cost
$511–$1,790 per $3–$6 square foot
Helical Steel Piers
This is the ideal solution for lightweight concrete slabs. Helical steel piers are threaded into the ground, and the weight of the structure is transferred to the load-bearing soil.
Cost
$30 per foot
Steel Piers
These peels are driven up to 100 feet deep into the ground. Once installed, they won’t move in soil that expands if they’re dug deep enough.
Cost
$700–$1600 per pier
Concrete Piers
Concrete piers are dug up to 10 feet into the ground, and it takes up to 10 days for the foundation to settle and even out.
Cost
$1.50–$24 per linear foot
Other Considerations
If our house is sinking, you should consult a professional immediately. Fortunately, there are methods and tools available to make the necessary repairs, but you can also reduce the risks of subsiding by removing any trees or bushes planted near your home; regularly pruning them can also stump their growth.
Additionally, consider carrying out regular inspections to check your home for foundation cracks, leakage, blocks, and any drainage issues.
