Flagstone, slate and other materials used for patios and flooring are often confused for each other, to the point that slate is often called ‘flagstone’. Whilst there are some similarities, particularly in how the two materials are used, there are fundamental differences in how the materials are made and the finished product. To help make sure you get the right look for your stone flooring, here is a look at the different types of material class as flagstones, and how they differ.

What is Flagstone?

A flagstone, or simply flag is less the name of a specific stone and more what it is used for.

Flagstone is a flat stone that traditionally was laid out as part of paths and roads. Traditionally it takes the form of sedimentary stones like sandstone, however, several other rocks have also been used in the same way and mistakenly called flagstone.

Sedimentary Flagstones

Sedimentary rocks are formed when layers of sand, particles and other materials settle in place and form layers of rock, which is what forms the unique patterns, layers and colours in sedimentary rocks. These include sandstone, which is sometimes described explicitly as flagstone, bluestone and limestone.

They have very unique looks and last a long time, but if you have carvings and details on sedimentary rocks they can sometimes be damaged due to erosion, water damage and acid damage.

Igneous Rock

Igneous rocks are formed by volcanic lava after it cools. As most volcanic rocks tend to be crystalline in nature they are not suitable to be used as flagstones, but the most common igneous rock, basalt has become increasingly popular.

Igneous rocks are exceptionally strong and are very good for absorbing sounds and retaining heat. However, over time they can end up looking dull, although this has made them very popular as indoor tiles.

Metamorphic Rock

Metamorphic rocks are rocks that transformed into a different shape and are the hardest to group. This transformation can be caused in different ways, although typically it involves a mix of intense pressure and intense heat. As a result, metamorphic rocks can take all sorts of different forms with very different textures, some which resemble sedimentary rock more and others with more of a crystalline, igneous rock-like finish.

The most popular form of metamorphic rock is slate, to the point that slate and sandstone used as flagstone can often be confused. They are both grey and layered, and often used in the same ways. The difference is in how they react to pressure.

The layers of slate can easily split, making it fragile for certain uses, whilst sandstone tends to erode.

Along with slate, there is quartzite, which is far smoother and far glossier a surface, to the point that like marble is often used for kitchen counter-tops and bathrooms as much as outside. This material is far harder to shape, much like marble, and so often is used in asymmetrical and unique paving designs based around the shape of different shards.