Split stone roofing is a traditional method of roofing that has been used for centuries. It is a unique and beautiful way to cover a building with a natural and long-lasting material. In this article, we will explore the history, terminology, stone types, production, and sizing of split stone roofing.
Split stone roofing has been used in Europe for hundreds of years, and it is still used today in many parts of the world. In the UK, it is commonly found on historic buildings, especially in the North of England and in Scotland. The use of split stone roofing became popular in the 16th century, and it continued to be used until the 19th century when other roofing materials, such as clay tiles and slate, became more prevalent. In the United States, split stone roofs were first used in New England in the late 19th century, and they became popular in other regions over time. The use of split stone roofing declined during the 20th century when the popularity of clay tiles and slate increased. However, it is still used today on some historic buildings and homes.
Stone slates are known by different names in various parts of the country, including grey slates, flags, flagstones, thackstones, slats, flatstones, stone tiles, and tilestones. Geologists prefer the term tilestone as these limestone and sandstone products are not, geologically, slates. Stone slate is, however, the most commonly used term and has been adopted in this technical advice note.
The process of cutting the stones into slates is called "splitting," where the term "split stone roofing" comes from. Split stone roofing is made from a variety of materials, including slate and limestone. It is also known as "split-face" stone roofing because the stones used for this type of roof have a rough surface that makes them easier to split into slates.
The most common types of stone used for split stone roofing are sandstone, limestone, and slate. Sandstone and limestone are often used in the Cotswolds or South of England, while slate is more commonly used in Scotland. The type of stone used for split stone roofing depends on the location of the building and the availability of the stone in that area. Both sandstone and limestone are very hard and durable so they can withstand exposure to the elements.
Most stone slates were surface delved rather than mined. Where the rock has been weathered, it is weakened along the bedding planes, allowing it to be split into thin layers of a suitable thickness for roofing. In some cases, the weathering actually completes the splitting process, and stone slates are found at the surface or turned up by ploughing. Traditionally, the delves tended to be small in scale, supplying one village or even a single farmstead, although some developed into large operations supplying industrial towns. Once the rock had been split to the required thickness, it was dressed to size and shape. In some cases, the faces of the slates were also tooled to provide a flatter surface. The slates were holed using a pointed tool, and fixings were used to hold the slates in place without slipping.
The size of the slates used for split stone roofing varies depending on the location of the building and the style of the roof. In the North of England, the slates are typically larger 18"-24", while in Scotland, they are smaller. The size of the slates also varies depending on the pitch of the roof, with steeper roofs requiring smaller slates.
In conclusion, split stone roofing is a traditional and beautiful method of roofing that has been used for centuries. Part two of this article will focus on the installation methods used with split-faced stone.