Last edited 06 Apr 2021


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.

Flagstone is available in numerous colours – such as buff, red and blue – which are usually determined by the natural cement material existing within the matrix of the stone.

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.

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