The hard stuff

A high-quality stone floor can do wonders to lift a flagship commercial development above the ordinary, and it can also add a touch of style to a domestic setting. But delivering such a finish comes with its own set of difficulties. For a start, there’s the need to create a level concrete sub-floor to take the stone or tiles. This often means a long wait for the screed to dry. And then there is the dust and dirt that comes with laying such a floor – not good news for any of the building’s finishes already in place.

On top of this are the questions of just how sustainable it is to use stone and how long its useful life is if it is permanently bonded in position. Solutions and alternatives are at hand, however, in this selection of three new developments in the world of hard flooring.

Stone raised access flooring

Next week, stone specialist Szerelmey will begin laying the stone floor for the main entrance of the new BBC building in Portland Place, London. Although it will give the impression of a traditional hand-laid monolithic stone floor, it is actually the first application of the firm’s Marmofloor stone raised floor system.

It’s been developed to offer the advantages of a raised access floor while at the same time eliminating the need for wet trades on site so speeding up installation and eliminating dirt.

The prefabricated system comprises traditional access floor pedestals which are fixed to the subfloor and adjusted to create a level base.

Onto these are laid the floor panels – a calcium sulphate board made from 95% recycled paper and gypsum – onto which is bonded the stone or hard floor finish. The boards are routed so that they interlock on installation, giving a monolithic structure.

However, the design incorporates a joint between the stone tiles for insitu grouting, giving it the appearance of a hand-laid traditional floor – something that stone fixed into individual raised floor trays without grouting fails to achieve.

The set-up is similar to the Technik system developed by Arup and stone specialist Grants. However, Szerelmey is looking to exploit the composite action resulting from bonding the stone or hard floor finish to the calcium sulphate board. According to Martyn Swash-Wallbank, contracts manager of Szerelmey Systems, tests are being undertaken at BRE. “The idea is that this will allow us to reduce the thickness of the stone and ultimately we want to optimise the system depending on the type and stone thickness, enabling us to use less material and create a lighter product.”

According to the company, the system is 10-15% cheaper than a traditional stone floor and faster to install, as there is no need to wait for a screed to dry. Another advantage is that by incorporating access points, the gap underneath the finished floor can be used for services. BRE tests have shown it is capable of supporting a 30kN point load.

Swash-Wallbank says the calcium sulphate boards can also be routed to allow pipework to be recessed for an underfloor heating system.

Take it with you when you move

InterfaceFlor is the pioneer of modular flooring – it was the brains behind the humble carpet tile when it was introduced in the mid-fifties. Since then it has been progressively refining its products but it is now applying its modular concept to hard surfaces.

According to the company’s sustainability director Ramon Arratia, this is partly for commercial reasons – countries such as Italy, Spain and Scandinavia simply don’t buy a lot of carpet and prefer ceramic and timber finishes – and also because it offers environmental benefits. “It’s aimed at the retail and office environments where churn rates are high,” says Arratia. The idea is that it can be easily moved or reused if the layout of the space needs changing. According to the company, it can also be laid six times quicker than a conventional ceramic or porcelain floor and can be walked on immediately after it is laid.

The Versaflex system has been developed to enable hard surfaces to have the flexibility of carpet tiles. What sets it apart from traditional ceramic flooring is the patent-pending system that holds the tiles in position.

A polymer grid is bonded to the back of the 10mm thick tiles, and this is laid directly onto the substrate to provide a uniform support. A detachable polymer “grout” then clips the tiles together and provides a seal in the junction between tiles. This does away with the need for traditional “wet” grouts and enables the tiles to be easily lifted and rearranged or taken away and reused elsewhere. It also means they can be used with access floors.

Twelve ceramic finishes are available and these can be mixed with the firm’s carpet tiles to increase design choice. Arratia says they are also considering other materials, including timber.

Walking on sea shells

A floor made of sea shells is a novel idea. In this case it’s also a sustainable solution. Kent-based South East Coatings has developed Shell, a seamless floor finish that is made up of 85% recycled sea shell aggregate sourced from a local fishery. These are typically cockle and scallop shells, which are held within a solvent-free epoxy resin.

Anna Hurst of South East Coatings says it was looking for a natural product that would provide a strong visual impact and began developing the product which uses a waste by-product from a nearby fishery.

Typically aimed at residential applications such as wet rooms, it can also be used to enhance commercial buildings, especially areas subject to impact, abrasion and spillages. The finish can be tailored by using larger or smaller sizes of aggregate or changing the ratio and sizes of shell fragments to deliver coarse or fine patterns. The colour itself depends on the proportions of the variegated cockle and whiter scallop. A pigment can also be added to the resin to complement the natural colour.

The finish is applied by trowel to a stable sub-floor in a thickness of about 12mm. After it has cured overnight, it is ground and polished, exposing the seashell fragments in a smooth surface. A stain-resistant top coat is also applied.