Cast stone is a unique material that provides multiple benefits for builders, developers and architects alike. A cost-effective alternative to natural stone, cast stone is chosen for its durability, versatility and strength, as well as its beautiful appearance. In this blog we explore the many benefits of choosing cast stone over natural stone and provide a complete guide to the material options available, manufacturing process and advice on specifying cast stone.
Cast stone is a special type of reconstituted stone. In building and construction cast stone is often preferred due to flexibility of installation and adaptability to create structural components. It is regularly used as an alternative to quarried stone as it looks, performs and weathers similarly to natural stone, but at a fraction of the cost.
Cast stone is also chosen over natural stone for its strength, colour, texture and for its freeze/thaw resistance. As it is free from the naturally occurring imperfections and stratification, found in quarried stone, it is much more versatile and adaptable than its natural alternative.
Cast stone is defined by the United Kingdom Cast Stone Association (UKCSA) as:
“Any product manufactured with aggregate and cementitious binder intended to resemble and be used in a similar way to natural stone”.
The use of cast stone as a structural material dates back thousands of years to ancient Rome, where pozzolanic cement was used along with other natural aggregates. Many important buildings and structures were created using this new combination of building material, including the vaulted arches and gateways of Rome’s Colosseum and the large span dome of Athens’ Pantheon.
Cast stone has been used by numerous civilisations since its early beginnings and a full history of its use can be found on the UKCSA website.
Cast stone has been used for centuries, but it had a renaissance in Georgian Britain, where many prestigious residential properties and public buildings were constructed using the material.
These days cast stone is chosen by builders, architects and developers around the world to complete architectural details of residential and commercial projects alike.
There are many benefits to choosing cast stone instead of natural, quarried stone.
Because cast stone components are produced using moulds, almost any design specification can be met, making it a very versatile material. Standard and bespoke designs can be produced with highly intricate detail, integrated structural reinforcing and lifting sockets, in contemporary, classical and traditional styles.
Cast stone is also regularly chosen by developers who need to create large volumes of the exact same components. Cast stone designs can be replicated in large quantities quickly and relatively cheaply, making it a much cheaper option that carved, natural stone.
Cast stone can also be easily used for both internal and external new-build projects and retrofit requirements. Plus, because it can easily match natural stone based on aesthetics and performance, cast stone is often the natural choice for restoration and renovation projects.
The constituents used to produce cast stone include:
Haddonstone is committed to an Environmental & Sustainability Management System. This includes a programme of continual improvements across our business to minimise our impact of our operations on society and the environment.
As part of our commitment to supporting long-term sustainability we source the highest-grade natural aggregates from Longcliffe Quarries, an environmentally responsible UK supplier. They are acutely aware of how their operations may impact the natural environment and as such, are committed to a programme of continual improvement to minimise its effect on the environment, prevent pollution and to provide a safe working environment for its employees.
Find out more about how we source our limestone aggregates in our blog.
There are two types of moulds we use in the production process: wooden moulds, for simple designs like window sills and coping stones, and rubber moulds for complex designs. Here’s how the fibreglass rubber-lined mould is created:
For Haddonstone (semi-dry cast limestone), the materials involved in this are limestone, white cement, sand, a small amount of water along with some secret ingredients. This mix produces the Portland colour – for other colours, pigment is added. We have two other materials as well: TecStone (wet-cast limestone) and TecLite (fibre-reinforced). Here’s how it works:
Curing is an essential process applied to de-moulded cast stone as it helps both its appearance and long-term strength and durability.
The curing process can take over two weeks to complete, depending on the size of the cast stone component.
To speed up this process and ensure our clients receive the highest-quality cast stone components quickly, we have invested in an accelerated vapour curing chamber at our manufactory.
We offer three high-specification cast stone material options to suit your unique requirements:
This is a unique form of cast limestone, with a surface texture, feel and strength similar to Portland or natural limestone. The principal materials for this are limestone, white cement and sand, a mix which has a feel of damp sand or earth. This stone is packed into the mould either by hand or a pneumatic hand rammer. No finishing is required with this material due to the quality of the mould manufacture and casting, resulting in a look that’s virtually indistinguishable from natural quarried stone and weathers beautifully.
While displaying similar properties to that of natural stone, cast stone is significantly more cost effective piece for piece, making it the ideal choice for many ornamental and architectural products. Our vapour curing process gives the stone the equivalent of 14 days’ strength overnight, which results in reduced delivery lead times and improved handling.
Download Haddonstone Data Sheet
We also manufacture products using a wet-cast production process – this material is called TecStone. Denser than our standard Haddonstone, it’s made of much larger particle sizes and exhibits a higher water content. The fluidity is created by plasticisers and super-plasticisers and the density of this material means that it doesn’t need vapour curing which means it doesn’t need vapour curing. Hand finishing is necessary at the end to ensure a high quality product. The TecStone mix is poured into a mould. This process gives a finish, once acid etched, much more akin to honed limestone. It has a smooth and sealed surface, which makes it ideal for flooring, fireplaces, complex statuary, larger architectural products and contemporary designs where clients prefer a surface finish that does not weather quickly. It’s also usually easier to clean for this reason.
We use TecStone for a number of our products, particularly those used in larger architectural projects, such as columns and paving. TecStone is designed to meet demanding performance criteria and as it can incorporate structural reinforcement, it tends to be the preferred material for architectural projects requiring structural strength as well as cast-in fixings.
This revolutionary cement-based material contains alkali-resistant glass fibre (Glass Fibre Reinforced Concrete). Although it closely resembles cast stone in appearance, the use of thin wall construction teamed with GRC/GFRC technology means the component weight is reduced by approximately two thirds when compared with similar Haddonstone and TecStone pieces.
Its high strength to weight ratio makes it ideal for new build, retro-fit, timber frame and new build projects. It can also be used to achieve the same crisp detailing normally only achieved with Haddonstone designs. Robust and lightweight, TecLite can be used in conjunction with Haddonstone architectural components.
The United Kingdom Cast Stone Association (UKCSA) states that all Full Members of UKCSA produce their cast stone to a higher compressive strength than BS 121.
As a founding member of UKCSA, all of our materials exceed the requirements of BS 1217:2008, BS5642-2: 1983 + A1 2014 and BS EN 13198: 2003.
We also regularly conduct quality checks on our cast stone materials, to ensure only the highest quality product reaches our clients.
According to the United Kingdom Cast Stone Association, choosing an UKCSA Member company gives the confidence required through the strict controls and standards adhered to, which include the manufacturing standards and procedures and third party testing and verification together with the social responsibility expected from a credible organisation.
All categories of cast stone products, whether semi-dry, wet-cast or fibre reinforced, have their relative advantages and should be considered as suitable or preferred alternatives to the natural stone they replicate. In addition to their manufacturing process is the quality of the raw materials, product durability, buildability, and most importantly the reliability, dependability and accountability of the manufacturer. Therefore it is essential that, whichever product category is selected, the supplier should be chosen extremely carefully.
We strongly recommend that cast stone components should only be installed by an experienced and trained installer.
Our team will be able to assist you in finding a suitable installer in your local area.
We have a range of helpful assembly advice on our website, including recommendations for pointing Haddonstone (semi-dry cast limestone) and TecStone (wet-cast limestone).
For architectural projects, installers can often assist with the cleaning and maintenance of cast stone components. Our team can help you choose an installer in your local area.
To care for your Home and Garden stonework and to keep it looking pristine, you should remove any build-up of dust, dirt and grime. To do this, we recommend using a gentle, non-invasive method such as cleaning your cast stone with fresh, clean water before applying a mild, environmentally-friendly detergent with a soft nylon brush. Learn more about caring for your cast stone designs in our helpful blog.
Repairs to small areas, chips etc. can be achieved with our pointing mix.
Whether you’re working on a private residential or large commercial project, or if you are interested in home and garden products, our friendly and expert team are happy to discuss your requirements.