The appeal of stone is unquestionable — when the right stone is specified for a room it can provide a long-lasting, durable floor, adding a timeless look and unique character. And while it’s been used in homes for centuries, its heat-retaining properties make it an excellent partner for modern-day underfloor heating. Added to this is the ongoing trend for continuing the same flooring outside — while in reality few interior products can be used externally, stone does lend itself readily to being matched with external pavers.
The Stone Choices
Slate, limestone, granite, travertine, basalt and some sandstones are all options. But stones which fall under these titles can vary considerably — quarried locally or imported from throughout the world, with varying grades of quality. Travertine, for example – a sedimentary rock deposited by mineral springs (air trapped during its formation results in its characteristic surface pits) – is available in different grades. Higher-quality travertine, often referred to as ‘premium’ or ‘first grade’, possesses fewer pits, with a more vibrant colour compared to those at the lower end, often referred to as ‘third’ or ‘commercial grade’. It may be supplied filled (where the pits are filled by hand and/or machine) or unfilled, with the tiler required to undertake the task.
Different stones and edge and surface finishes – such as honed, riven, polished and vein cut – are also suitable for different applications. It goes without saying that rooms subject to lots of wear require a hardwearing surface, often with a tile of adequate depth — 20mm is good for durability. A highly polished finish may require more attention to keep in tip-top condition in such areas, too, so you may want to opt for a riven finish with slate (the uneven surface is more forgiving when it comes to marks), or tumbled, which has a pre-aged appearance. “In our opinion, a dense limestone is the most suitable material available for high-traffic areas in the home,” recommends Paul Cranney of The Stone Gallery, who offers a product called ‘Juma Beige’ for this application. Granite is also a good option.
In the bathroom stones with lower porosity, such as slate, granite, marble and also some limestones, are good choices. While all reputable stone tiles offered to the UK market are tested for slip-resistance, do bear in mind that a highly polished finish can present more of a slip hazard when wet. In the kitchen marble, which is more sensitive to acid than stones such as granite, may not provide the best solution as spills could more readily result in etching.
Choosing a Format
The choice of size and shape is usually dictated by aesthetics, room size and budget. In addition to standard sizes, some suppliers offer ‘free lengths’ whereby the width remains the same but the length varies, as well as the option to purchase tile packs of varying format to lay in a set pattern; both work well in more traditional schemes. For contemporary homes long, narrow tiles are particularly striking.
Suppliers tend to keep a stock of their standard sizes, but bear in mind that bespoke formats (which are typically more expensive) may be on lead times of six to eight weeks, or longer if the stone is imported.
So, is installation a DIY job? It certainly can be, but if you’ve invested considerably in your stone tiles then making savings through DIY installation can be a false economy — as it’s a task which demands perfection. “It’s a job for the professional; we’re constantly being asked for advice on repairing failed floors due to poor fitting,” warns The Stone Gallery’s Paul Cranney. “Unfortunately our advice usually entails starting again from scratch.”
Finding a professional tiler with expertise in stone flooring is a safe bet. “In the current economic climate, it can be very tempting to accept possibly lower prices offered by builders for laying stone floors, especially as you may have built up a relationship if they’re doing other works. But I’d always recommend a professional stone tiler,” says Joss Thomas, MD of Indigenous. “Stone is a law unto itself and needs to be understood. Thicknesses may vary and if variation isn’t taken out using the adhesive, the floor won’t be level. A good stone tiler will also know how to select and blend the floor, ensuring that variation in colour is spread equally over the surface.”
The grout used will also impact on the overall look. One striking trend is the use of light grout between dark tiles; however, a darker grout, which more readily hides stains and dirt, is more practical. Sealing the stone, in accordance with the supplier’s advice is also an absolute must.
What lies beneath the tiles is also paramount to ensuring you achieve a long-lasting floor without problems. Timber floors might require strengthening and a flexible adhesive which accommodates movement, preventing the tiles from cracking. An uncoupling membrane is also a good idea (more to follow).
Installation with Underfloor Heating
Stone is a great covering with underfloor heating, but you’ll first need to check with your supplier that the product is suitable. Additional care also needs to be taken with installation, by using a flexible adhesive and an uncoupling membrane, such as the Schlüter-Ditra (01530 813396). This membrane works like an underlay — applied between the substrate and the tiles, it accommodates for movement and temperature differentials, preventing the stone above from cracking. Paul Cranney of The Stone Gallery explains: “There has been a shift in opinion regarding the laying of natural stone floors. The Stone Federation of Great Britain is now recommending the use of uncoupling membranes, following problems when stone is fixed on newly laid screed floors with underfloor heating. In our opinion, the problems have arisen due to the premature use of maximum heating causing a shock to the screed, which in turn culminates in cracks that are transmitted through the stone.”
A screed needs to dry out properly and preferably be heated gradually and allowed to cool before the stone is installed.
Stone-effect ceramic – picked up for as little as £15/m2 – or (more expensive) porcelain tiles can be alternatives if you like the look of stone, but don’t want to invest in the real thing. The uniformity makes installation an easier DIY task. Increasingly popular is stone applied to a ceramic or porcelain backing, which could be ideal where tile depth is an issue, such as in renovation projects.
Usually limestone or slate, machine-finished to create a smooth surface. Left: Lovell Purbeck’s Purbeck Royal Blue in standard gauge widths and random lengths; £100/m2 (01929 439255)
The stone block is split, exposing the natural texture or cleft. Slate is often riven cut, which lends a rustic look and more readily hides marks, but bear in mind that furniture may be prone to wobble on the uneven surface. Left: Burnt Sienna Natural Slate from the Earthworks Collection by Original Style; from £39.95/m2 (01392 473000)
An ‘aged’ finish with softer-looking edges suggesting the stone has been reclaimed. Left: Mandarin Stone’s Nautilus tumbled limestone; the 610 x 406 x 12mm tile shown starts at £59.99/m2 incl VAT (01628 485015)
Buff-coloured limestones were all the rage, but in recent years we’ve seen more homeowners buying darker stones,” says Simon Hart of Lovell Purbeck. “‘Aged’ stone is also popular.”
While light stones can make a room feel more spacious, darker flooring can be a more forgiving option, hiding dirt and marks (but beware if you have a golden dog!).
“Large-format tiles are almost replacing more traditional sizes — they create a seamless finish (with less grout lines) and continue and enhance the trend for open plan living, aesthetically making a room feel larger,” adds Beth Boulton, Head of Marketing at Topps Tiles.
A growing desire to reduce the carbon footprint created by importing goods and recognition of the quality of locally quarried products has also seen more homeowners opt for stone produced in the UK, such as Purbeck, Bath and Portland stone.