Underpinning consists of adding extra support to the foundation of your building, and if the soil around your building has changed or if subsidence has occurred, it may be time for underpinning. Wondering how to detect if underpinning is necessary? Here are a few signs that it's time to consider it:
1. Sinkholes have been detected near your building.
Subsidence refers to the motion of the earth's surface in a downward direction, and while this can occur in a range of conditions, it can occur when some of the rock under the surface dissolves and creates a sinkhole. In particular, if your building is in an area with a lot of limestone and some of the limestone has dissolved, this can create holes under the surface, and that can cause the surface to sink. If this process has been happening on any of the land around your building, you may want to consult with a geologist to see how the earth is doing under and around your building. That can help you determine if you need underpinnings for support.
2. A drought has caused changes to the water table in your area.
In other cases, changes to the earth's surface may be linked to changes in the level of the water table. Additionally, if there have been a lot of droughts in your area, that can change the moisture levels in the soil, potentially causing the foundation of your building to sink further in the soil.
If there have been significant changes in the level of precipitation in your area, you may want to speak with a surveyor to see if the level of your building is stable, and if it's not, you may want to consider strengthening the foundation of the building through underpinnings.
3. Old mines have been discovered in your area.
If someone discovers an underground mine near your building, that is another sign that the ground supporting your building's foundation may not be totally stable. In that case, you also may want to consult with a surveyor. Keep in mind, however, that potential disrupters to the surface don't necessarily need to be as deep and expansive as a mine. You may also face issues due to tree roots, drains or other openings under ground.
4. The foundation has cracks.
In addition to monitoring the ground around your foundation, you should also look at the foundation for signs that it may need a bit of extra support. Namely if you see a lot of cracks in the walls of your foundation, especially around doors or windows, you may want to consult with an underpinnings expert for advice.