Posted on: 3 April 2017
If your home's foundation is unstable, you may need to hire someone to do underpinning to strengthen the foundation so it's sturdy enough to hold up your home. There are a number of situations in which underpinning may be essential, but subsidence, changes to the elevation of the land, can definitely require you to need underpinning.
If you're worried about subsidence, there are several things you may want to investigate. All of the issues below are potential signs that your area may have an increased risk of subsidence, and as a result, you may want to set up a savings account in case subsidence occurs and you need to put underpinning on your home.
1. Inaccurate Soil Assessment
In most cases, the original builder of your home likely took soil samples to determine how to set up your foundation. However, if the chemical makeup of your soil has changed or if the samples were taken incorrectly in the first place, that can potentially lead to subsidence and cause foundation instability. To be on the safe side, consider taking a new soil sample and comparing it to the original sample used by the builder. If you don't have access to your old soil samples, you may want to take a new one and have an expert estimate whether or not subsidence may be an issue.
2. Presence of Limestone
Unfortunately, when there is a lot of limestone in the ground beneath a home or any other type of structure, the limestone can get washed away by water travelling underground. That can cause sinkholes, and if that occurs near your home, it can disturb your foundation and require you to need underpinning. To see if that's likely to happen in the near future, you may want to figure out what type of rock bed is underneath your home.
3. History of Extraction or Mining
If you're trying to assess your risk for subsidence, you may also want to investigate the history of land use in the area. In particular, in areas with a lot of mining or extraction, there may be an increased risk of subsidence. If possible, look into the history of the area and see if those types of activities have happened there.
Earthquakes can also cause subsidence in an area. If you know that your home is in an area prone to earthquakes, you may also want to make a plan in case subsidence happens. If earthquakes are already happening, you may want to talk with an underpinning expert about strengthening your foundation proactively.