Tufa and tuff
Contents |
[edit] Introduction
'Tuff' and 'tufa' describe two types of stone – both of which have been used throughout history for construction. The terms are often used interchangeably (sometimes erroneously) but they have totally different origins. Despite this, and in both cases, the result is a porous, sponge-like rock that is soft, durable and extremely light for a stone; this characteristic has been exploited in its use for vaults as well as external walls.
[edit] Tufa
Tufa (or tufo) is the term applied to a stone that is formed by calcareous particles laid down over many centuries as a sediment at a hot spring, lake shore or other location. Sometimes called ‘tufaceous limestone’ or ‘calcareous tufa’, the calcareous particles are deposited as a precipitate as the water flows over organic material such as twigs, leaves, mosses and shells. When the water evaporates, the organic material becomes calcified to produce a stone with inherently rich, natural patterns.
Tufa is light and was used chiefly from Saxon times to the 14th century. Its main use was one for which it seems to have been specially ‘made’: vaulting – such as in the rebuilding of the choir of Canterbury Cathedral following the fire of 1174, and also for the vaulting in Bredon Church, Worcestershire.
Tufa can be seen used in association with Kentish ragstone at several churches in Kent; with chalk in the Isle of Wight and with carboniferous limestone in Matlock, Derbyshire. The Norman church at Moccas, Herefordshire, is built mostly of tufa. There are also extensive tufa deposits in Worcestershire and in Dorset (where it has been used with Purbeck limestone). In the Cotswolds, Berkeley Castle is the largest building in England to have been constructed mainly from tufa.
Today, tufa is mainly used for gardens and pond features, alpine rockeries, rock walls and fountains.
[edit] Tuff
Tuff is the volcanic variety of the stone and is relatively soft, hence its use in construction. It is formed from successive layers of ash ejected from the vent of a volcano and later compacted over geological time. Volcanic tuff is extremely durable and was used by the Romans as an external facing for buildings.
[edit] Other varieties
Hypertufa is an artificially made stone comprising various aggregates bound by Portland cement. Used as a substitute for natural tufa, its porosity facilitates plant growth and is thus used for pots and garden ornaments. It was originally invented for use in alpine gardens.
[edit] Related articles on Designing Buildings Wiki
- Types of stone.
- Choosing stone.
- Defects in stonework.
- Etruscan architecture.
- Finding stone to conserve historic buildings.
- Inspecting stone sample panels.
- Kentish ragstone.
- Masonry.
- Modern Stonemasonry.
- Natural stone cladding.
- Natural stone for Interiors.
- Natural stone.
- Patio stone.
- Portland Stone.
- Sourcing stone to repair Exeter Cathedral.
- Stone dressing.
Featured articles and news
Boiler Upgrade Scheme and certifications consultation
Summary of government consultation which closes 11 June 2025.
Deputy editor of AT, Tim Fraser, discusses the newly formed society with its current chair, Chris Halligan MCIAT.
Barratt Lo-E passivhaus standard homes planned enmasse
With an initial 728 Lo-E homes across two sites and many more planned for the future.
Government urged to uphold Warm Homes commitment
ECA and industry bodies write to Government concerning its 13.2 billion Warm Homes manifesto commitment.
From project managers to rising stars, sustainability pioneers and more.
Places of Worship in Britain and Ireland, 1929-1990. Book review.
The emancipation of women in art.
Call for independent National Grenfell oversight mechanism
MHCLG share findings of Building Safety Inquiry in letter to Secretary of State and Minister for Building Safety.
The Architectural Technology Awards
AT Awards now open for this the sixth decade of CIAT.
50th Golden anniversary ECA Edmundson awards
Deadline for submissions Friday 30 May 2025.
The benefits of precast, off-site foundation systems
Top ten benefits of this notable innovation.
Encouraging individuals to take action saving water at home, work, and in their communities.
Takes a community to support mental health and wellbeing
The why of becoming a Mental Health Instructor explained.
Mental health awareness week 13-18 May
The theme is communities, they can provide a sense of belonging, safety, support in hard times, and a sense purpose.
Mental health support on the rise but workers still struggling
CIOB Understanding Mental Health in the Built Environment 2025 shows.
Design and construction material libraries
Material, sample, product or detail libraries a key component of any architectural design practice.
Construction Products Reform Green Paper and Consultation
Still time to respond as consultation closes on 21 May 2025.
Resilient façade systems for smog reduction in Shanghai
A technical approach using computer simulation and analysis of solar radiation, wind patterns, and ventilation.