Tips & Guidance on Natural Stone Paving
The following has been produced as a guide to the characteristics & properties of natural stone products.
A benefit of natural stone, as no two pieces are the same, allows bespoke appearance & design compared to other paving products. Each piece is uniquely formed with its own colour variation, mineral veining, markings & characteristics, often enhanced when wet.
Mineral content can appear as patches or inclusions, veins (which can be mistaken for cracks), striations and fossils. Minerals such as iron may oxidise & appear over time due to weathering, and not be visible prior to installation.
When choosing a natural stone product, a number a things must be considered:
– sample pieces are only a small representation of the variation of colour.
– mix from as many crates as possible to better blend the colours, if laying from only one crate, sort out different colours before laying.
– breakages are expected and these are normally used for cuts.
– consider the area being paved for surface finish, some paving giving more grip than others, shaded areas causing damp & algae growth, direct sunlight causing fading over time.
– dust sediments causing scratches & tool marks can be present on the stone, from the production process of the stone, and generally naturally weather away.
– external factors can affect natural paving also, such as, cleaning acids, weed killer, fertilisers and metal structures left on the stone, staining the stone.
– aftercare is all part of the process. Natural stone can be stained by algae & lichen growth, bird droppings, tree sap, leaf stains, so regular sweeping & cleaning is recommended, and sealing may be considered after a period of time.
– efflorescence is a naturally occurring salt deposit in or on the surface of the stone. These deposits can come from a reaction in the cement used or be naturally present in the stone. This should weather away over time.
– after laying, some stone can flake, where the top layer comes away due to weathering or frost and can not be prevented. This does not affect the strength or durability of the stone.
– other weathering causing stains & changes in appearance can be caused by saturated ground under the paving soaking up through the stone, acid rain & UV light causing fading, especially in darker limestones.
– when using a professional landscaper, always ask about the non-use of spot bedding, installing upside down, butt jointing and the use of recommended chemicals, whether for sealing or cleaning.