Why older buildings are different
Many period properties have solid (rather than cavity) walls, lime-based mortars and renders, and a construction designed to “breathe” letting moisture move in and out. Problems often arise when modern, impermeable materials are applied to them.
Defects most often seen
- Trapped damp: cement renders, modern gypsum plasters and impermeable paints can trap moisture in solid walls, causing damp and decay.
- Timber decay: rot and beetle in embedded timbers, floors and roofs, often linked to damp.
- Movement and cracking: shallow historic foundations and past alterations can lead to settlement.
- Roof spread, and chimney and flashing defects.
- Outdated services: old wiring and plumbing needing upgrade.
The golden rule: use compatible materials
Repairs to older buildings should generally use breathable, compatible materials (lime mortars and plasters, breathable paints) rather than sealing them up with cement and plastic-based products. The wrong repair can do more harm than the original defect.
Advice
Because period buildings need specialist understanding, a detailed (Level 3) building survey is usually the right choice before buying or undertaking works.