If your property is suffering from subsidence, it’s really important to find the cause. This is because even after remedial works such as underpinning, resin injections, and other building work, the problem can reoccur if the original cause hasn’t been dealt with.
One of the most common causes of subsidence is leaky drains. Here, we’ll take a look at how this can happen, and the effect of a drain leak on the ground around your property – and crucially, how the problem can be fixed.
What is subsidence?
First of all, it’s important to know what subsidence is, how to recognise when it’s happening, and why it’s so serious.
Subsidence is where the ground around and under the foundations of a property sinks, shifts or settles. This creates instability, which can create serious structural damage to anything built on top.
For your home, it could mean large cracks, sloping floors and doors and windows that stick (because the openings are no longer square and true). It can be very expensive to fix, as well as affecting the value of your property and potentially causing insurance issues too.
How leaky drains cause subsidence
A number of things can cause subsidence, from the growth of tree roots to major weather events such as earthquakes, floods, and extended periods of unusually heavy rain. Excessive groundwater pumping has also been known to cause it, by lowering the water table.
But one of the most common causes of subsidence is related to drainage problems. If a drain pipe installed underground develops a crack, hole or a leak, the water it carries simply leaks out into the surrounding earth instead. In the case of a drain that completely collapses, this can start to happen quite quickly.
All of this excess water in the ground is bad news for your property. It can soften and loosen the subsoil around and underneath the foundations, so that they’re no longer able to adequately support the weight of the building on top. It also makes it more likely that tree roots will grow towards the area (in search of water). Unfortunately, this can exacerbate the situation even further.
In some types of soil, an issue called sulphate ingress can happen. This is where sulphates in the ground and water can start to erode concrete foundations. In serious cases, this can cause structural damage as well as subsidence.
What to do to fix the problem
Both leaky drains and subsidence are urgent issues that require professional attention.
If you’ve started to notice diagonal cracks in your walls, particularly around windows and doors, these could be the first signs of subsidence.
If this is the case, the next step is to investigate potential causes – starting with the drains. A subsidence specialist can help, carrying out a site survey and testing the soil around your property.
Of course, you might also experience things the other way around, noticing the signs of a leaking outdoor drain before you even start to think about subsidence. Common signs include slow-draining water from your sinks and other fixtures, pools of standing water in the garden, or bad odours coming from the drains.
While these signs aren’t good, it’s preferable to spot these instead of the signs of subsidence. This is because it could mean you have time to fix the leak and stabilise the ground before subsidence starts to affect the structural stability of your home.
You can act fast and bring in a specialist in drain collapse repairs to prevent structural damage, which could save you a great deal of money and stress further down the line.
