The Test and Itchen are among England’s best-known chalk streams. Winchester, Romsey and the villages along their valleys have some of Hampshire’s most attractive homes: flint and brick cottages, thatched houses and listed townhouses.
Chalk, rivers and groundwater
Much of central Hampshire sits on chalk, which drains freely. But chalk aquifers can rise after very wet winters, and the river valleys have higher water tables. Homes close to the rivers can see damp floors and cellars as a result.
Flint walls and lime mortar
Flint walls rely on generous amounts of lime mortar. When that is replaced with hard cement, or walls are rendered with impermeable materials, moisture can become trapped and damp patches appear inside. Failed rainwater goods on flint walls are another common source of penetrating damp.
Listed and period buildings
Many properties around Winchester are listed or in conservation areas. Damp treatments need to suit the building, and consent may be needed before work. The best approach is often to address external causes and use breathable materials.
Signs to look for
- Damp patches at low level on solid walls
- Crumbling mortar and lime render
- Decay in timber floors with poor sub-floor ventilation
- Woodworm in older floors, roof timbers and beams
We cover Hampshire from Farnborough and Basingstoke through Winchester to the coast. See damp proofing in Hampshire and timber treatment in Hampshire.





