ResidentialPeriod Townhouse Restoration
Lime Plastering · Decorative Plaster
Quick answer
Why use lime plaster instead of gypsum?
Lime plaster is vapour-permeable and slightly flexible, so it allows moisture in solid brick, stone and timber-framed walls to evaporate rather than becoming trapped. Gypsum and cement-based plasters are much less breathable and can lead to damp, salt damage and decay in older buildings. Lime is usually the correct material for buildings constructed before around 1920.
Understanding older walls
Traditional buildings have no cavity or damp-proof membrane behind the plaster. They rely on the wall being able to absorb and release moisture. When modern gypsum or cement is applied, that moisture can be driven into the wall or trapped behind the finish, which often shows up as blistering, salts and damp patches.
We use non-hydraulic lime putty plasters and natural hydraulic lime (NHL) where a slightly faster set is appropriate, often with hair or fibre reinforcement on laths.
Repair and replastering
Where possible we repair rather than replace original lime plaster, consolidating sound areas and patching in matching material. Where modern plaster has caused problems, it can be removed and the wall re-plastered in lime.
Lime work is slower than gypsum: each coat needs to cure properly and conditions must be controlled. We programme work accordingly and explain how to care for the finish afterwards.
Benefits
- Breathable, reducing trapped moisture in solid walls
- Compatible with original building fabric
- Flexible, accommodating slight movement
- Suitable for listed and conservation-area buildings
- Can be finished with breathable limewash or mineral paints
Suitable property and project types
- Georgian, Victorian and earlier homes
- Listed buildings
- Timber-framed and cob buildings
- Churches and heritage buildings
- Barn and farmhouse conversions
