Portland Stone
St Paul’s Cathedral. |
Portland Stone is a type of limestone that is commonly used in the construction of traditional buildings in the London area.
Limestone is a sedimentary rock formed during four geological eras: Cretaceous, Jurassic, Permian and Carboniferous, 70 – 345 million years ago. It consists of calcium carbonate, and is formed by the compaction of calcite, primarily from marine organisms, at the bottom of shallow lakes and seas. The presence of marine organisms and other fossil inclusion is often noticeable in limestone. Due to the presence of a variety of minerals, limestone also presents numerous colours, ranging from light grey Portland Stone, to creamy Bath stone and dark grey Purbeck stone.
Portland Stone was formed at the end of the Jurassic period, approximately 145 million years ago. It has been quarried on the Isle of Portland in Dorset since Roman times, and has been used as a building material in London since the 14th century, when it was used in the construction of the Palace of Westminster, the Tower of London and London Bridge. St Paul’s Cathedral, designed by Sir Christopher Wren, was built from Portland Stone, establishing it as the stone of choice for London. During the 19th and early 20th centuries Portland Stone, became popular for building banks, civic buildings and educational establishments, many of which were in the classical style.
It is strong, durable, resistant to weathering, easy to work and carve and can be used for masonry walls, cladding, columns, plinths, flooring, paving, mouldings, sculptures, fireplaces and so on. There are a number of different varieties of Portland Stone, with different appearances, properties and recommended uses depending on the bed that it has been extracted from. These include:
- Bowers Basebed.
- Bowers Roach.
- Fancy Beach Whitbed.
- Grove Whitbed.
- Jordans Basebed.
- Jordans Whitbed.
- Ostrea Patch Reef Whitbed.
[edit] Related articles on Designing Buildings Wiki
- Choosing stone.
- Defects in stonework.
- Finding stone to conserve historic buildings.
- Inspecting stone sample panels.
- Iraq, Afghanistan, Gulf War Memorial.
- Julian Opie Art Wall CitizenM Tower of London Hotel.
- Kentish ragstone.
- Limestone.
- Modern Stonemasonry.
- Sourcing stone to repair Exeter Cathedral.
- Stone dressing.
- Sustainable stone.
- Two New Ludgate Portland Stone Feature Wall.
- Types of stone.
- Use of Stone in Monks Lantern Weybridge.
Featured articles and news
Not buildings. Happy holiday from DB.
Future Homes Standard: Industry calls for more ambition
As the Government FHS consultation finally closes.
Improving government projects with data and AI
Enabling better outcomes, efficient modern delivery and influential leadership on government projects.
BSRIA Living Laboratory Innovation Challenge
Final days for submission, closing March 29.
Windows, their frames, forms, factors and functions.
The hidden subtleties of U-Value calculations
Different contexts and what to include as variables.
A brief run down with related articles.
Electrical sector calls for safer public EV charge points
Serious concerns about electrical safety in the public domain.
Building Blocks manifesto presented to parliament
Architects Declare call in for support of five critical policies.
The four elements of project management with APM
Analysis, expectations, collaborative communication and partnerships.
City of London launches Heritage Building Retrofit Toolkit
Empowering owners to initiate necessary adaptations.
Guidance on RAAC in listed buildings
Published by Purcell, endorsed by IHBC, SPAB and C20.
Learning from the past.
Reluctance to hire people with criminal convictions revealed
Employing People with Criminal Convictions Report.
Tackling unconscious bias; Women's History Month
Personal reflections, as the last week of March approaches.