Cast Stone Versus Natural Stone

Natural stone has been used in building and construction for thousands of years, but it was in the eighteenth century – when classically inspired country houses rose in popularity – that it became the preferred material of choice for the building industry. Can cast stone be considered a viable alternative?

Katherine Kates, Production Director at Haddonstone, discusses the main differences between the two types of stone and tells us why cast stone can be a cost-effective alternative to natural stone and explains how it is used in a broad range of building projects undertaken today.

What is the difference between natural and cast stone?

Natural stone is an organic material that has undergone many years of geological change. The stone is unique offering many variations in grain, texture and colour. This stone is excavated from the ground via quarrying, where it is then cleaned, cut and finished. The most popular types are limestone, marble, granite, slate, sandstone and travertine.

So, what about cast stone – what is that? The United Kingdom Cast Stone Association defines it as; “any product manufactured with aggregate and cementitious binder intended to resemble and be used in a similar way to natural stone”. Haddonstone’s cast stone is such a type of stone. It is produced using a blend of limestone, pigments, additives and cement. The resultant mixture is then packed into specially created bespoke moulds before being cured and/or finished.

What are the drawbacks of natural stone in the building industry?

Natural stone – while undoubtedly appealing – is prone to imperfections and stratification, which can spoil its appearance. The process of extraction, cutting and finishing can be time consuming, meaning increased lead times and meeting exacting project specifications with a material like natural stone can be hard. A big disadvantage is, unlike cast stone, natural stone cannot be moulded into any size or shape, so its design and construction options are limited. Finally, many of the natural stones mentioned above are imported from Asia and southern Europe, which adds significantly to their carbon footprint.

What are the benefits of specifying cast stone?

The highest-quality cast stone will have the appearance of natural stone and is almost impossible to distinguish from its quarried equivalent. In addition, because cast stone components are produced using moulds, almost any style and scale – including highly-intricate designs and patterns – can be achieved and, at reasonable cost. Particularly important in the architectural world, the ability to match colour, texture and material is also possible with cast stone, making it the ideal material for restoration and replication work, as well as new-build projects.

In terms of cost, cast stone is a far more competitively priced material than natural stone while offering a wider expanse of architectural possibilities. In the context of construction materials, cast stone’s performance is impressive; with a compressive strength of 35 Megapascals of pressure per square millimetre. What this means is it can significantly withstand heavy loads, while it weathers in a similar way to natural stone and has a sound freeze/thaw resistance level.

One of the most flexible construction materials, cast stone can fit all your needs when it comes to production and installation, as during manufacture components can be structurally reinforced with steel or fixing and lifting sockets can easily be integrated, plus stonework designs can be adapted to meet specific architectural requirements. Cast stone designs can be manufactured to exact colour, textural and material specifications, which ensures against natural imperfections and achieves a beautifully consistent finish.

When it comes to stringent environmental considerations, Haddonstone are committed to supporting long-term sustainability and reducing environmental impact, as we only source the highest-grade, British natural limestone aggregates to produce our cast stone designs.

But how durable is cast stone?

Cast stone is much more durable than say, Bath stone, for example. Part of the reason is that cast stone has no natural bed, so its surface will not flake, meaning it will withstand even the harshest of conditions. This is why our cast stone was the ideal solution to replace the existing parapet of the Spa in Scarborough, a delightful Grade II* Listed property. Using cast stone enabled our team to successfully recreate the beautiful and sophisticated design of the original, after its stone had been badly damaged following years of erosion caused by the sea air and spray from the North Sea.

Our work will mean the restored parapet of this wonderful building will remain structurally and decoratively sound for many years to come – despite its rather exposed location on Yorkshire’s east coast. In fact, we were awarded the prestigious Gold Award (Building Materials) for Environmental Practices and Sustainable Development in The International Green Apple Awards which recognise leaders in environmental practice and sustainable development. For further information, call 01604 770711 or visit  www.haddonstone.com