Guides
Subsidence information for homeowners in Hampshire
Find out what a crack means, how different soils behave across the county, and what repair methods a specialist might use. Each guide answers one question you might have about your home.
What a specialist looks at first
A subsidence survey establishes whether movement is active or historic, and what is causing it. The specialist examines cracks, checks door frames for distortion, and looks at the soil beneath the foundations.
Seasonal cracking and structural movement leave different marks. Knowing the difference means you can describe exactly what has changed when you report the problem. Mention when the crack first appeared, whether it widens in dry weather, and if any doors have started to stick.
If you have noticed a new crack and are unsure whether it needs a professional opinion, find out what happens during that first visit and what information the specialist needs from you before arriving.
Repair methods used in Hampshire
Underpinning deepens foundations to reach stable ground. Resin injection fills voids beneath a slab without excavation. Screw piling drives steel piles through soft fill to a load-bearing stratum. Each method suits different soil conditions and building types.
These guides explain how a specialist firm carries out each repair, what disruption to expect inside your home, and why one approach is chosen over another. Concrete floor repair covers sunken slabs in kitchens, driveways and patios where the ground below has washed out or compacted.
Reading about the methods beforehand means you can ask informed questions when a firm quotes for the work. The guides do not recommend one technique over another, because the right choice depends entirely on what the survey finds beneath your specific home.
Cracks in older and unusual walls
Hampshire has many homes built with flint, cob and chalk block. These materials move differently from modern brick, and lime mortar behaves unlike cement. A crack in a cob wall does not always mean subsidence; it may reflect normal moisture cycling.
Outbuildings present their own problems. Garage walls, porches and garden walls often sit on shallow foundations that respond quickly to tree roots or frost. This guide separates structural concerns from superficial damage in smaller structures.
Coastal and waterside homes frequently stand on made ground, reclaimed marsh or soft silt. Subsidence on filled land follows different patterns than movement on natural clay. The guide for these sites explains what a specialist considers when the original ground was disturbed decades or centuries ago.
Soil behaviour and seasonal signs
Clay shrinks in dry summers and swells when rain returns. This cycle opens and closes cracks around window frames and above door lintels. If you notice gaps appearing in August and closing by November, clay shrinkage is the likely cause.
Removing a large tree near your home can trigger heave, where the soil expands and lifts floors upward. The resulting cracks look different from settlement cracks, and the repair approach changes accordingly. Old wells, infilled cellars and buried ponds also create localised voids that collapse years later.
Valley floors and areas near rivers sometimes sit on peat or soft silt. These compress under the weight of a house over time. Recognising which soil lies beneath your home helps you understand why movement started and what conditions might worsen it.
Ruling out other causes of cracking
Not every crack points to subsidence. Thermal expansion, poor construction joints, vibrating traffic and rusting wall ties all produce damage that mimics foundation movement. Jumping to the wrong conclusion leads to unnecessary expense.
Tapered cracks, diagonal lines running through bricks rather than along mortar joints, and sticking doors carry specific meanings. Visual clues separate subsidence cracks from those caused by other factors.
Find out whether the signs you see genuinely suggest ground movement or whether the problem sits elsewhere in the structure. Either way, you make a better decision about what to do next.
Town-by-town soil and building guides
Hampshire geology changes rapidly over short distances. Southampton sits partly on reclaimed estuary ground. Basingstoke homes rest on chalk and clay-with-flints. Fleet houses are surrounded by heathland sand and mature trees. Each combination produces distinct subsidence patterns.
These guides cover individual towns across the county, explaining the typical soil, common building styles and the problems specialists see most often in each area. If your home is in Gosport, Fareham, Winchester or any other listed town, the relevant guide describes the ground conditions you are likely dealing with.
Knowing your local geology matters because repair firms base their approach on what lies below. A method that works on Andover chalk downland may be unsuitable for Lymington silts. Start with your town guide to understand the context before reading about specific repair techniques.
Ask about cracks in your home
Send details of what you have noticed. A specialist firm receives the information and decides whether a survey is needed. There is no fee for this enquiry and no obligation to proceed.
- No cost to enquire
- No obligation to proceed
- Details go to a specialist
Subsidence Guides
- Clay shrinkage
Cracks that open in summer and close in winter often mean clay soil shrinking as it dries. What to look for in Hampshire homes and when to seek advice.
- Heave
Heave after tree removal can crack walls, lift paths and leave doors binding at the top. Signs to watch for, why clay swells back and what helps next.
- Wells and voids
Old well under house subsidence often shows as a localised dip, sinking path or sudden crack in older homes. What these signs mean and what comes next.
- Peat and soft ground
A house built on peat ground can settle as soft alluvium, silt and made ground compress over firmer gravel. Signs to look for and what to check next.
- Other crack causes
Wondering is my crack subsidence? Compare thermal cracking, failed lintels, rusting wall ties, plaster shrinkage and dropped arches before worrying.
- Signs & Advice
Signs of subsidence include diagonal cracks wider at the top, doors and windows that stick, and sloping floors. See which signs matter most.