All buildings settle over time. Settlement causes no problem if it’s uniform across a building’s entire foundation. However, if one section of a building settles faster than others, structural damage may occur.
How a structure settles depends on its weight and the characteristics of the soil it sits on.
While foundation settlement is fairly common in Colorado, it’s every builder’s and homeowner’s worst nightmare. Here, we will shed light on differential settlement, which can have a damaging effect on your home.
What Is Differential Settlement?
Differential settlement is the uneven or unequal settling of a building’s foundation. This phenomenon occurs when the soil under your foundation contracts, expands, or shifts irregularly. Differential settlement causes the structure to settle at a variable rate.
When this occurs, the affected building develops small or large cracks and gaping in the concrete walls and floors. You may even notice uneven problems with your doors and windows.
What Causes Differential Settlement?
Let’s look at some of the reasons that might cause your home’s foundation to sink unevenly.
Highly compressible soils have a weak bearing capacity. Structures erected on such grounds require special footings to help spread the load of the building over a wider area. This will help prevent differential settlement.
Poorly Compacted Soils
During the construction of a building, the ground may require artificial leveling and filling to ease the construction process. When adequately compacted, this fill soil provides a substantial base for supporting the foundation. If not properly packed, the ground may settle unevenly under the building’s weight, leading to structural damage.
Clay soil is one of the worst soil types for building. This is mainly because this soil swells with water during wet seasons and shrinks during the dry months. Soil that behaves this way is highly expansive.
If your foundation sits on clay soil, you are likely to experience differential settlement after some time. Your footing will settle downwards during the dry seasons as the clay shrinks.
The bedrock is one of the strongest supports a foundation can have. This, however, does not mean that it is immune to differential settlement. Sometimes, the bedrock may intercept the footing trenches, causing differential settlement. Hilly and rocky areas tend to have shallow and outcropped bedrocks. Builders find it hard to dig through such soil to cast trench footing.
Signs of Differential Settlement
The effects of differential settlement may appear immediately after a building’s construction or take decades to manifest. Some obvious signs of differential settlement include;
- Foundation cracks: This is one of the first signs that something is brewing. Watch out for cracks that appear wider at the top and narrow at the bottom.
- Sticking doors and windows: When a foundation settles, it can slant the wood framing, throwing the doors and windows out of plumb. As such, they may not close as smoothly as they should.
- Uneven floors: Your floors may also get so out of level that a tennis ball or marble will roll when placed on the floor.
Other signs of differential settlement include bulging walls, sinking exterior stairs, and tilting chimneys, among others.
Once the foundation of your Denver, CO, home starts showing signs of differential settlement, you should ask your contractor to further investigate the issue. Left unchecked, differential settlement can lower the structural integrity of your building.
Underpinning a settling foundation with push piers provides an effective way to lift and stabilize your home. These piers offer a permanent solution to your settlement issues. Other piering solutions include helical piers and slab piers. Your contractor will be able to help determine which of these solutions would be the best for your home and its foundation.
When it comes to foundation issues, prevention is vital. Builders should start by assessing the soil to confirm that it is perfect for the type of structure they want to put up. Ideally, you should build a house on soil layers with minimal clay or silt. This way, you will not have to worry about the soil under your foundation shrinking and expanding. If possible, the house should sit on native soil and not fill soil.
Before any construction work starts, get a structural engineer to determine the load-bearing capacity of the soil. The engineer will advise you on whether the ground needs some improvements or amendments early enough and whether a deep foundation is necessary.
Foundation Repair in Denver, CO
At Complete Basement Systems, we can help stop your foundation from settling unevenly. If you have any foundation concerns, contact us today to schedule a free foundation inspection and quote and get a lasting fix to your problem.