Cracks in Walls: When to Worry & How to Fix Them

When should you worry about cracks in your walls?

Discovering cracks in walls and ceilings can be concerning. Whether they appear suddenly or worsen over time, you may be wondering when you should start to worry about them.

Sometimes, small cracks in walls are just cosmetic flaws and they’re easy to cover with some simple DIY, yet they could also be indicators of more severe structural problems.

There are several reasons why you may experience superficial cracks in interior walls , such as settling, seasonal weather changes or minor vibrations from everyday living. However, not all small cracks are harmless and they can be an indication of sinking or damaged foundations. Recognising the signs of serious structural damage is the first step to ensuring the integrity, safety and value of your home.

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How to fix cracks in walls

When it comes to fixing cracks in walls , the solutions vary based on the severity and underlying causes. For minor, non-structural cracks, you can use a joint compound or spackle to fill them. Not only will this improve the appearance of your interior, but also prevent the cracks from expanding.

For more significant, structural cracks, it’s crucial to contact professionals. Early intervention from subsidence technicians can save you a lot of money and hassle in the future.

Hairline Cracks v Structural Cracks

Identifying subsidence cracks in internal walls is key to addressing any potential structural issues before they cause significant damage. Cracks caused by subsidence typically appear diagonally or stepped, rather than the vertical cracks that are more common in aesthetic wall problems. Subsidence-related cracks are often wider at the top than the bottom too and generally speaking, cracks wider than 3mm are cause for concern.

They can also widen or change over time, indicating ongoing movement in the foundations. Where the cracks are is also an important indicator of subsidence, cracks near structural weak points like doors and windows or several cracks along the same wall can be a sign of subsidence.

As touched on above, not all cracks indicate problems with the structural integrity of your home. Small hairline cracks in plaster walls, especially near the corners of rooms or where the walls and ceilings meet, are often caused by things like damp patches drying or plaster expanding and contracting with changing weather.

If you have cracks in plaster and you’re wondering when to worry, check whether you can insert a coin into the crack. Larger cracks that grow over time, appear in multiple places or are accompanied by other signs of subsidence, like door frames sinking or sloping floors, require immediate attention.

subsidence crack in external wall

subsidence crack in external wall

internal subsidence crack

internal subsidence crack

Should I be worried about cracks in walls?

Although cracks can occur for lots of different reasons, there are a few key characteristics that indicate internal cracks in walls might be caused by subsurface movements and there is cause for concern. If you have cracks on interior walls, floors or ceilings that are getting wider, have a zigzagging pattern or branching formations, and are clustered in the same area, it may be time to start worrying. These types of cracks often suggest structural weaknesses and foundational shifts, and you may have subsidence.

When you notice worrying cracks in your home, you should contact a subsidence specialist straight away. They have the skills and experience required to repair cracks in walls, and prevent further damage caused by subsidence. Typically, expert technicians will conduct a detailed inspection of the cracks and your home’s foundations to determine the structural health of your home.

If subsidence is found, remedial measures may be required to maintain the long-term stability of your home. Traditionally, techniques like underpinning were recommended, but now modern alternatives like resin injections can address the root causes of the cracks.

How to Fix Cracks in Walls

Covering small cracks in walls

For minor cosmetic cracks, DIY solutions are often suitable to fix structural cracks in walls . You can use a range of caulk or filler materials available at local DIY stores to fill cracks in walls and you don’t need to be an expert to achieve perfect results. Commonly, you just need to clean out the crack and remove any debris, apply a suitable filler, and then sand down the area once it’s dry. You can then simply paint over the filler to disguise the cracks.

Fixing large cracks in walls

If you think the problem is more serious, don’t try to fill large cracks yourself. Instead, call the professionals and get some expert help with fixing subsidence cracks . Getting a professional assessment and suitable repairs are crucial to protect your home for years to come.

DIY fixes simply won’t work for structural problems and your home might need to be raised, re-leved and re-supported. With the help of modern technology, this process is easier than ever before and subsidence issues can be fixed quickly without significant disruption.

Contacting our team at Subsidence Ltd is the best way to fix cracks in internal and external walls . Our expert assessments and specialised treatments can rectify the underlying problems, ensuring your home remains safe for years to come. We use resin injections that don’t require planning permission or extensive digging.

There are several benefits to using resin materials and when compared to conventional methods, we can stabilise your property much faster. With our professional help, you can have peace of mind knowing your home is structurally sound and potentially save significant amounts in future repairs.

If I have subsidence cracks, how much will it cost to repair them?

If you have cracks in your walls and ceilings, and you’re worried about the underlying damage to your home’s foundations, you shouldn’t put off getting expert help due to the costs involved with subsidence repairs. It’s a common misconception that to fix structural cracks in walls , you need to have your home underpinned and there is a cheaper option available.

You may be surprised by how budget-friendly professional repairs can be when you enlist the help of an experienced company that uses alternative techniques to conventional underpinning.

Key Takeaways

Not all cracks are serious – A lot of the time, they are harmless (e.g., cosmetic shrinkage cracks).

Hairline cracks (<1mm) are usually normal, caused by drying plaster or minor settling.

Worry if cracks are:

• Wider than 3mm (especially if they are growing).

• Diagonal or stepped (indicating subsidence/heave).

• Near doors or windows (signs of structural movement).

• Accompanied by sticking doors or windows (suggests foundation shifts).

Common causes of cracks:

• Subsidence (soil shrinkage, clay movement, leaks).

• Thermal expansion or contraction (temperature changes).

• Poor construction (e.g., inadequate foundations).

When to act:

• Monitor cracks (tape test to check growth).

• Seek expert advice if cracks are wide, multiple, or worsening.

Solutions:

• Cosmetic cracks: Fill and repaint.

• Structural cracks: Underpinning, resin injections, or wall ties (professional repair needed).

Remember: Early assessment prevents costly damage, so contact a specialist if unsure.

Contact Subsidence Ltd for a free consultation and quote

To get some tailored advice from our team at Subsidence Ltd about the cracks in your walls, ceilings or floors, get in touch with us today. We pride ourselves on our many years of experience addressing subsidence issues across the UK and we can help you keep your home and family safe.

We have carried out over 2,000 jobs to date and have over 16 years experience, so you know you are in safe hands.

We also offer flexible payment plans and discounts for neighbour postcodes.

Contacting us is the first step towards stabilising your home and preventing further structural issues.