Kent guides
What cracks in walls mean and where to start
Read the guide that matches what you have noticed at home. Each one explains what the ground under your house might be doing and what to do next. Nothing to pay and no obligation to follow up.
Understanding cracks and movement in your home
A crack in plaster or brickwork does not always mean subsidence. It can be seasonal drying, settlement from when the house was built, or a failing drain washing soil away. The first step is knowing which type of movement you are looking at.
The opening guide covers how cracks appear in a home and why some widen while others stay hairline. It separates normal settling from movement that needs a specialist to look at the footings.
If you are unsure whether the crack matters right now, the guide on judging urgency walks through what to watch for over the coming weeks. It explains when a reading should be taken before any repair starts, so a structural engineer has evidence rather than guesswork to work from.
Ground conditions across Kent
Kent sits on several different types of ground, and each behaves differently when the weather changes. Weald clay shrinks in summer and swells in winter. Chalk dissolves slowly, leaving hidden voids. Brickearth near Thanet is fine sand that washes out if water finds a path.
Separate guides cover each of these soils. They explain where in the county you will find them and what kind of damage they tend to cause. A house on Gault clay near Sevenoaks moves for different reasons than one on reclaimed marsh near Sheerness.
Older industrial land brings its own problems. Houses built over former chalk pits or cement works along the Thames and Medway may sit on fill that compresses unevenly. The guide on old quarry land explains how this shows up in walls and floors years after construction finished.
Houses shaped by their history
Many homes in Kent were not built as houses. Converted oasts and barns often have shallow footings that were never meant to carry residential loads. Ragstone walls and tile-hung facades crack in patterns distinct from modern brickwork.
Homes backing onto railway cuttings sit on ground that was moved and compacted during Victorian engineering. Embankments settle over decades, and drainage installed beside the track can fail silently.
New builds on infill plots face different questions. The guide on new houses explains the difference between early settlement, which usually stops, and ongoing subsidence, which does not. Knowing which one you have prevents unnecessary worry and avoids expensive mistakes when arranging repairs.
Surveys, monitoring and repair methods
Once the cause of movement is understood, a specialist firm can recommend what to do. A structural movement survey records the pattern of cracking and measures distortion across the walls. Crack monitoring uses small gauges fixed either side of a fracture to record whether it opens or closes with the seasons.
Drainage surveys use a camera pushed through pipes to find fractures leaking water into the ground beneath the footings. A broken drain is a common cause of localised sinking.
Repair methods vary by site. Underpinning extends the foundations deeper into stable ground. Resin injection fills voids and compacts loose soil without heavy excavation. Screw piling drives steel shafts down to firmer layers. Each method suits different access conditions, soil types and budgets. The individual guides explain what each involves and when a specialist would recommend it.
Guides for every town in Kent
Movement looks different depending on where your home stands. A terrace in Gillingham built on London clay behaves differently from a clifftop house in Ramsgate sitting on chalk. Town-specific guides describe the local geology, typical building styles and the problems homeowners report most often.
Maidstone, Ashford, Canterbury, Dover, Folkestone, Tunbridge Wells, Tonbridge, Dartford, Gravesend, Rochester, Chatham, Sittingbourne, Margate, Herne Bay, Deal and Sheerness each have a dedicated page. These explain which streets sit on made ground, where old streams were culverted and which areas see repeated claims for subsidence.
Reading the guide for your town gives context to what you see in your own walls. It tells you whether neighbours share the same problem or whether something specific to your plot needs investigating.
Ask about a crack in your home
Send a brief description of what you have noticed. An adviser reads it and suggests which guide applies or whether a specialist firm should visit. There is no charge and no commitment to proceed.
- No fee to ask
- No obligation to proceed
- Advice based on Kent ground
What cracks mean
- Weald and Gault Clay
Clay soil subsidence in Kent makes cracks open in summer and close in winter on Weald and Gault clay. Learn what to look for and when it matters.
- Dene Holes
Dene holes in Kent are old chalk shafts found between Dartford, Gravesend and the Medway towns. Learn the signs of a hollow and what checks can follow.
- Brickearth
Brickearth subsidence around Thanet, Herne Bay and the Swale coast: how fine wind-blown soils and sands move, the cracks they cause and what to check.
- Old quarry land
A house built on an old quarry, brickfield or cement works along the Thames or Medway can settle unevenly. What causes the cracks and how it is checked.
- Marshland
A house built on reclaimed marsh or riverside fill can settle as soft ground compresses. Signs to look for on the Thames, Swale and Romney marshes.
- Ragstone walls
Cracks in ragstone walls and behind tile hanging rarely show as neat steps. How movement looks in traditional Kent buildings and what to check next.
- Cliffs and landslip
Cracks in a house near cliff ground can point to slope movement or landslip on the chalk and clay coasts of east Kent and Sheppey. What to look for.
- Orchards and hops
A house built on old orchard or hop ground can crack as tree roots and dried clay settle. What the cracks suggest and which ground checks help.
- Railways
Cracks in a house backing onto a railway cutting, embankment or tunnel line may follow slope movement or clay shrinkage. What to look for and record.
- Oasts and barns
Cracks in a converted barn or oast often trace back to shallow farm footings never meant to carry a house. What the pattern suggests and what to check.
- Crack widths
Crack widths in millimetres line up with damage grades from hairline to severe. See how to measure yours and what width alone can and cannot tell you.
- Urgent or wait
Cracks in walls are serious in some cases and harmless in many others. Here are the signs that point to real movement and the ones that can be watched.
- New build plots
Cracks in a new build house or a garden infill plot can mean settlement, poor fill or ground movement. What the patterns suggest and when a survey helps.
- Common questions
Common subsidence questions answered, from what cracks look like and what a survey covers to monitoring, underpinning and who carries out the work.