A stair step crack in brickwork on an external residential home wall

What are the signs of subsidence?

Subsidence signs can focus on cracks in walls. While this is accurate, cracks in walls aren’t always a sure sign of subsidence. The key to knowing whether cracks in walls are a sign of subsidence is to pay attention to their pattern and progression. Typically, subsidence cracks run diagonally and get wider over time.

The most common subsidence symptoms include:

Diagonal cracks in interior and exterior walls

Cracks that are wider than 3mm

Windows and doors sticking or jamming

Uneven or sloping floors and surfaces

Gaps appearing between ceilings, walls, skirting board and coving

Cracks in walls & brickwork

The most common and talked about sign of subsidence is cracks in walls, both internally and externally. You can easily identify whether the cracks around your property are a sign of subsidence by checking to see if they:

  • Run diagonally or in a zig-zag pattern
  • Follow the mortar lines that also step up or down
  • Are wider at the top when compared to the bottom
  • Are present around doors, windows and other openings into the property
  • Get wider over time

You may have noticed several hairline cracks around your property, but they’re usually very common and are not a cause for concern when it comes to subsidence. However, if they’re wider than 3mm, or start to get bigger, then it should be looked at by a professional firm, like us here at Geobear. Here’s how you can tell if cracks are a more serious sign of subsidence:

  • They continue to widen over the course of time
  • They suddenly appear
  • They come about after long, dry periods, especially during the summer
  • They’re visible both externally and internally, in the same place on the wall

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Windows & doors sticking

If your doors or windows have become more difficult to close or open, or if you’ve noticed that the frame itself has warped or shifted, then it could be a sign of subsidence. This normally happens because:

 

  • One section of the foundation has moved more quickly or more substantially than the others
  • The brickwork has distorted, even if it’s slightly
  • The frames themselves have become warped or misaligned

 

It’s important to bear in mind that doors and windows can stick on a seasonal basis, as the temperatures rise and fall or when conditions become more humid. This is because wooden doors and frames swell and contract with changing weather patterns. However, if your windows and doors stick or jam on a regular basis, regardless of the weather, then it could indicate subsidence.

View looking out from inside home through partially opened window.
View of a level spanning a depression in a residential home's wooden floor

Sloping floors and uneven surfaces

Uneven floors, ceilings and surfaces can indicate structural movement. However, older properties will often have historic settlement. When it comes to sloping ceilings, floors and other surfaces, the question should be asked of ‘is the movement active?’.

If the floors, ceiling or surfaces feel as though they’ve become more sloped or uneven over the course of time, then you’ll need to have a subsidence survey carried out by us here at Geobear to confirm instances of ongoing structural movement.

Gaps between walls, ceilings, or skirting boards?

Small, visible gaps between ceilings, walls, skirting boards and coving will appear if differential ground movement is at play. Although it seems like a small thing, it can mean that a structural shift is occurring. Look for gaps forming between:

  • Skirting boards and flooring
  • Skirting boards and walls
  • Walls and ceilings
  • Coving and ceilings
  • Other internal partitions

 

View of corner of internal wall with floor visibly sunken creating a gap between the wall and floor.
Resi home window frame subsidence cracks

Are there any external signs of subsidence?

Yes. There are some external signs of subsidence that you should be aware of. When looking for them, pay close attention to one section of the building, as subsidence will often only affect one side of the property as the foundations shift. Here are some external subsidence signs:

  • Cracking under rendering
  • Cracked patio slabs, driveways or garden paths close to the property
  • Gaps between the main house and an extension
  • Boundary walls that are leaning to one side

 

View of a curved brick residential wall showing two large stair-step cracks caused by subsidence.

When you should be concerned about subsidence?

There are some instances where subsidence signs are completely harmless, such as hairline cracks or seasonal door and window jamming, for instance. However, there are some signs of subsidence that should not be ignored and will require further assistance from a subsidence specialist, like us here at Geobear.

Here’s when you should seek further guidance:

Cracks, either inside or outside of the home, are 3mm or wider

Cracks are running diagonally or are stepping up or down the brickwork

Cracks have appeared after a period of long, dry weather

Doors/windows suddenly start binding or sticking

You’re noticing active movement of the property, including the building leaning to one side

External corner of residential home bricks with settlement cracking visible in the brickwork

Steps to take if you suspect subsidence

If you think that your property is experiencing subsidence, then you should book a professional subsidence assessment as soon as possible. Our team of subsidence specialists are able to carry out free video inspections on a wide range of properties to help determine whether subsidence is at play. In the meantime, it’s recommended that you take an inventory of the subsidence signs you’ve noticed, along with a progression report on things like crack width and length, for example.
Here’s what you should do while you await our support:

1
Take photographs of the signs you’ve noticed

It’s beneficial to take photos of the same sign on a week-by-week basis to track progression. This helps to determine whether the structural movement is active or historic

2
Measure the crack width and keep a record of it

Do this regularly and note down the date the crack was measured, along with its exact width

3
Keep records

Keep an accurate and up-to-date record of any progression of subsidence signs you’ve noticed

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Do I need to have my house underpinned if I spot signs of subsidence?

 

No. Not all signs of subsidence mean that underpinning is necessary. However, with Geobear, underpinning isn’t normally required. This is because we use a modern method of soil and foundation stabilisation, without the need to excavate the grounds. This means that:

  • No large trenches will need to be dug
  • You won’t need to move out of your home
  • Disruption is minimal
  • We won’t make any mess
  • The installation is far quicker and more efficient

Learn more about how to treat subsidence.

View of dry, cracking clay soil with a little green grass on the edges. Deep cracks are visible in the soil.

Why do signs of subsidence appear in the summer?

In Britain, soil shrinkage is a common cause of subsidence, especially if your property is built on clay soil. It’s caused by sudden increases and decreases in moisture levels in the soil. As the moisture increases, the clay soil expands, and as it decreases, the clay soil contracts. This is often why subsidence will make itself apparent during the summer months, especially after prolonged periods of dry, hot weather.

During long, dry summers, clay soil will:

1

Lose moisture

2

Shrink considerably

3

Pull away from the building’s foundation as it contracts

4

Cause your home to settle unevenly

Frequently asked questions about signs of subsidence

When signs of subsidence are spotted around the home, whether internally or externally, then it’s natural to have a lot of questions about what it means and when to worry. We’ve answered some of the most common questions about subsidence that we’re often asked by homeowners in order to give you some advice and support regarding signs of subsidence.

Subsidence, heave and settlement describe different forms of ground movement, and so the terms cannot be used interchangeably. Here’s what the differences are between them all:

  • Subsidence - this is when the ground beneath a building shifts or sinks unevenly. It’s often caused by soil issues, such as clay soil shrinkage, for instance
  • Heave - this is the opposite of subsidence. Instead of downward movement, it references upward movement as a result of clay soil swelling after extreme hot or wet weather or after a large tree has been removed from the grounds of the property
  • Settlement - this is typical downward movement of a new property. It happens as the new structure compacts the ground below as it gets used to the new weight on top

While you can spot the classic signs of subsidence in and around the home, the only way to tell if subsidence is the problem is to have a professional subsidence survey carried out by a Geobear expert. Otherwise known as a site investigation, it aims to identify, assess and determine the causes of the structural movement, which is the first step in having the problem rectified.

No. Hairline cracks, for instance, aren’t a sign of subsidence, typically. Most homes will have minor cracks throughout, usually as a result of temperature changes. If a subsidence crack is present, it’s usually obvious to homeowners, usually because they’re wider than 3mm, are visible in brickwork both inside and outside of the property, and run diagonally or in a step-up or step-down fashion.

No. Most homes have minor hairline cracks in the plaster that appear over time due to normal temperature changes. Subsidence cracks are different—they are typically diagonal, wider than 3mm (the width of a 10p coin), and are often visible both inside and outside the property.

It’s rare for a property in Britain to collapse as a result of subsidence. This is usually because the signs are spotted and the problem is rectified long before it gets to this point. Subsidence normally takes place over a long period of time, taking months, or even years, to become apparent. While it is a serious structural issue, it’s often one that’s addressed before it becomes a severe, irreversible problem to the point where the foundations fail.

Yes. Subsidence can definitely be fixed. Modern engineering solutions, like the one we use here at Geobear, are highly effective at repairing subsidence. The Geobear method is expertly designed to fix the problem at source. It does this by strengthening the ground beneath the property, improving ground conditions and providing stable, ongoing support for the foundations. It’s a solution that will last for decades to come.

If you have your property underpinned using conventional methods, then it can take weeks, or even months, to complete the work. On the contrary, Geobear’s geopolymer resin injection method is extremely quick, efficient and convenient. Most residential projects will be completed within just one or two days (depending on the size of the property and the complexity of the issue), and with minimal disruption. This means you can carry on with normal life as soon as possible.

You need to inform your home insurer if you suspect subsidence. If the issue is unresolved, then it could make it difficult to take out insurance or even switch providers. As such, you need to resolve subsidence issues as soon as possible in order to satisfy the requirements of most home insurers.

You can prevent subsidence by:

  • Maintaining drains and gutters to prevent leaks
  • Ensuring large trees and shrubs are planted a safe distance away from the property to prevent roots from penetrating the ground beneath the foundations
  • Pruning large, established trees and shrubs to reduce the amount of water their roots take away from the soil
  • Preventing the pooling of water on patios, paths and driveways

Subsidence cracks are usually wider than 3  mm, but they may widen over time if the structural movement is active.

Yes. Seasonal clay soil movement can mean that cracks will widen and close up again as the weather changes. However, repeated ground movement cycles can make the structural problem worse over the course of time. Alternatively, you’ll notice that cracks will close up when you choose Geobear for subsidence solutions. As the resin injection is pumped into the ground, it will fill gaps and voids in the soil beneath the foundations, hardening as it goes. This will actively lift the property back up to its original position, causing any subsidence cracks to close.

It’s not usually a dangerous issue. However, continually ignoring the signs of subsidence can make its resolution more costly and complicated the longer it’s allowed to go on. If the property is left to subside for decades, then it could cause the collapse of the building itself, although this is a very rare occurrence.

Worried about your home?

If you've noticed any of these signs, don't wait for the problem to get worse. Contact our expert team today for a professional assessment and a clear plan to secure your home.

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