Lath and plaster
Lath and plaster is a technique which was used to finish interior walls and ceilings from the early-18th until the early-to-mid-20th century. It was then generally superseded by drywall techniques and plasterboard.
The process involved laths (thin strips of timber) nailed to timber joists or posts and then covered with built-up layers of plaster. Laths typically measure 25 mm x 6 mm, and are positioned about 6 mm apart from each other to allow the plaster to penetrate into the gaps between them.
Typically three coats of plaster would then be applied:
- A ‘render’ layer about 6 mm thick to bond to and fill the gaps between the laths.
- A ‘floating’ layer about 6 mm thick to provide a relatively smooth surface for the third layer.
- A ‘setting’ layer about 3 mm thick to provide a completely smooth finish for decoration.
The first and second layers typically used a 1:3 lime putty to clean, sharp sand mixture. Animal hair was often added to assist with binding. The mixture for the third layer was usually a 3:1 lime putty to fine sand mixture or lime putty on its own.
As time went on, gypsum or cement was added which helped to reduce the setting time between layers.
The advantage of using lath was that it allowed for ornamental or decorative shapes, and could provide sound insulation and fire resistant properties.
However, it was a skilled craft and was a time-consuming activity and so was largely replaced by the use of pre-manufactured plasterboard towards the middle of the 20th century.
[edit] Related articles on Designing Buildings
Featured articles and news
ECA Industry Awards 2024 shortlist revealed
22 leading businesses from across the electrotechnical and engineering services sector.
Government unveils Skills England strategy
Skills England to transform opportunities and drive growth.
New Government Hub for York Given Planning Green Light
For up to 2,600 civil servants, due for completion by 2028.
Construction Skills Certification Scheme cards
July update on Professionally Qualified and Academically Qualified Person Cards.
BSRIA Briefing 2024, November 22
Sustainable Futures: Redefining Retrofit for Net Zero Living.
The CLC on driving competency in the retrofit sector
Previously published roadmap on skills for net zero.
The first labour government King's speech in fifteen years
Construction industry reactions, support and some concern.
CIOB Retrofit of Buildings Technical Information Sheet
What retrofit is, the approach to be taken and processes to be followed.
Adapting Historic Buildings for Energy and Carbon Efficiency
Historic England advice note 18, free download published.
10 retrofit projects revisited 10 years after completion.
Information orders, building liability orders and SPVs
Key BSA terms and how they impact special purpose vehicles.
Listed despite problems with its design.
Zen and the art of cycling exploration.
Design Council Homes Taskforce launched
To support government 1.5 million homes target within UK climate commitments.