A flagstone (sometimes called a ‘flag’) is a flat slab of stone used for paving, walkways, driveways, patios, flooring and occasionally roofing (shingles). Since the Saxon period, flagstones of various sizes were used for internal flooring purposes in castles and other structures.
Traditionally, natural flagstones are quarried from sedimentary rock. This sedimentary rock can have various compositions and characteristics. One of these is the distinct stratification (or bedding planes) which allows the stone to be easily cleaved, i.e readily separated, into largish, irregular but sometimes rectangular pieces. It is frequently a fine-grained sandstone interbedded with thin, shaly or micaceous layers, but can also be a limestone.
Depending on the application, flagstone tends to be durable and weather resistant and can be cut into smaller pieces to create interesting patterns. It also provides a naturally slip-resistant finish if properly maintained.
Building with Scottish Stone, published by the Natural Stone Institute and the Scottish Executive in 2005, defines flagstone as: ‘…generally a layered (thinly bedded or laminated) sedimentary rock (sandstone or siltstone) capable of being naturally split or riven into large thin slabs suitable for paving. Some flagstone quarries are capable of producing 'stone slates' for roofing.
 Related articles on Designing Buildings Wiki
- Bituminous mixing and laying plant.
- Britain's historic paving.
- Coal holes, pavement lights, kerbs and utilities and wood-block paving.
- Code of Practice for Ironwork Systems Installation and Refurbishment.
- Floors of the great medieval churches.
- Floorscape in art and design.
- Hazard warning surfaces.
- Highway drainage.
- How to lay block paving.
- IHBC articles.
- Penarth Alabaster.
- Permeable pavements.
- Road improvement scheme consultation.
- Road paving.
- The Institute of Historic Building Conservation.
- Types of road and street.
IHBC’s 2021 virtual conference examines how we can best change and sustain places for the benefit of people, led by expert practitioners boasting international, national and local profiles and experiences.
One of the most stunning Roman finds ever unearthed in Britain has been discovered on the site of a new housing development in a village near Scarborough.
The latest issue (no.167) of the IHBC’s membership journal Context is now out, boasting a tight focus on Urban Design, with a distinctly international take.
Europa Nostra has announced the list together with its partner, the European Investment Bank Institute.
Work is underway on an ambitious project to virtually ‘clone’ Bradford city centre, as a ‘Digital twin’ will open the door to a 3D world with virtually endless possibilities.
The support will create dozens of opportunities in heritage repair and construction and waterways management, funded by the Department for Work and Pensions.
The 2021 edition of the Building Conservation Directory, also available online, has been published. Find skilled trades specialising in work to historic and traditional buildings.
BT has revealed that almost 4,000 of its iconic red phone boxes across the UK are available for local communities to adopt for just £1.
On 26 March the IHBC, led by Prof. John Edwards, hosted a free one-hour CPD webinar ‘Introduction to Building Survey for Retrofit’ for sector professionals.
Greg Clark, writing an opinion piece for RICS, explores how good governance in cities pays dividends.