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 It was then generally superseded by drywall techniques and plasterboard.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
Shading for housing, a design guide
A look back at embedding a new culture of shading.
The Architectural Technology Awards
The AT Awards 2025 are open for entries!
ECA Blueprint for Electrification
The 'mosaic of interconnected challenges' and how to deliver the UK’s Transition to Clean Power.
Grenfell Tower Principal Contractor Award notice
Tower repair and maintenance contractor announced as demolition contractor.
Passivhaus social homes benefit from heat pump service
Sixteen new homes designed and built to achieve Passivhaus constructed in Dumfries & Galloway.
CABE Publishes Results of 2025 Building Control Survey
Concern over lack of understanding of how roles have changed since the introduction of the BSA 2022.
British Architectural Sculpture 1851-1951
A rich heritage of decorative and figurative sculpture. Book review.
A programme to tackle the lack of diversity.
Independent Building Control review panel
Five members of the newly established, Grenfell Tower Inquiry recommended, panel appointed.
Welsh Recharging Electrical Skills Charter progresses
ECA progressing on the ‘asks’ of the Recharging Electrical Skills Charter at the Senedd in Wales.
A brief history from 1890s to 2020s.
CIOB and CORBON combine forces
To elevate professional standards in Nigeria’s construction industry.
Amendment to the GB Energy Bill welcomed by ECA
Move prevents nationally-owned energy company from investing in solar panels produced by modern slavery.
Gregor Harvie argues that AI is state-sanctioned theft of IP.
Experimental AI housing target help for councils
Experimental AI could help councils meet housing targets by digitising records.
BSRIA Occupant Wellbeing survey BOW
Occupant satisfaction and wellbeing tool inc. physical environment, indoor facilities, functionality and accessibility.