Subsidence is a very specific issue that occurs when the ground under your house collapses, or sinks lower, taking some of the building’s foundations with it. This puts strain on your home’s structure as one side sinks, causing cracks to appear.

The overall subsidence rating is divided into 3 categories: Negligible – Very Low, Low, and Moderate to High. As this data is not property specific, further enquiries should be made to clarify the actual risk of subsidence at a property if the potential (Low, Moderate to High) has been identified.

You can tell if a crack is as a result of subsidence if it’s:

1. more than 3mm thick, and gradually getting wider.
2. runs diagonally across the wall.
3. Is wider from top to bottom.
4. clearly visible from inside and from the outside of the property.
5. occurs near doors and windows.
6. Causes rippling in wallpaper.

Subsidence can occur when the ground below the house shrinks or swells due to the weather – during wet weather the ground expands due to the moisture but then contracts during the dry summer months. So, as much as we may crave a long hot summer, it’s certainly not ideal for homes built on clay.

A subsidence report, also known as a Homecheck Mining and Subsidence Report, informs you if your property is in an area affected by subsidence due to soil shrinkage. Subsidence is one of the greatest risks to properties and is the fear of many a home owner as the costs to repair can be in the tens of thousands.

The subsidence investigation usually involves accurate monitoring of any movement of the building or structure. This includes precise datum monitoring of principal fractures and, where appropriate, precision level survey monitoring of datum fixed close to the foundations of the building or structure.

Subsidence – sinking of the ground because of underground material movement—is most often caused by the removal of water, oil, natural gas, or mineral resources out of the ground by pumping, fracking, or mining activities.

I tried searching for similar issues on subsidence but can’t find any (probably used the wrong keywords). Anyway, I am in the process of buying a house and I asked for an environmental search. The search report (from GroundSure) came back stating that there is a moderate-high risk of natural ground subsidence.

I thought the part “not in an area subject to subsidence” refers to the “moderate-high risk natural ground subsidence” in the search report. However, shouldn’t the insurance company know about the soil type of a particular post code? Insurance companies will always use weasel words.

Land subsidence occurs when large amounts of groundwater have been withdrawn from certain types of rocks, such as fine-grained sediments. The rock compacts because the water is partly responsible for holding the ground up. When the water is withdrawn, the rocks falls in on itself.

The subsidence data provided within our reports is not property specific and is designed to highlight the highest risk ranking within a 50m buffer. The overall subsidence rating is divided into 3 categories: Negligible – Very Low, Low, and Moderate to High.