• Limestone Tiles and Terracotta Tilesvs.Glazed PorcelainTiles

• Demanding Applications:kitchen and bathroom tiles

• Sealing Limestone Tiles,Terracotta Tiles and Slate Tiles.

• Under-floor and under-tile heating.

At Terra Firma we supply a wide range of natural products as well as ceramic tiles and as a result we often get asked about their relative merits. To some extent one can give some objective facts and figures, but part of our job is to try and match a product to a customer. This means trying to determine whether concerns about maintenance in what may be a low traffic area are misplaced or trying to establish whether given a certain budget it is worth compromising on the look to minimise maintenance headaches down the line. 

Most decisions about wall or floor tiles can usually be broken down into 3 basic considerations; cost, aesthetics and practicality. For most people it is the tension between these three considerations that mean that visits to tile shops usually take longer than 5-10 minutes. Quick decisions only really occur when one of these factors is not really an issue.

Cost: Porcelain alternatives to Slate tiles are usually more expensive and are normally only chosen when durability on commercial projects is paramount.Terracotta tiles are broadly similar in price to their alternative  porcelain equivalents.There is however usually a substantial difference in price between Limestone tiles and their porcelain equivalent.Some Commercial/2nd.choice Travertine tiles will be cheaper than porcelain,but its suitability in reality is only for light duty internal cladding rather than kitchens or bathrooms.

Limestone Tiles: The price of ceramic/porcelain tiles and their terracotta or slate tile counterparts are sort of comparable. On the whole a ceramic tile will be noticeably cheaper than  limestone tiles counterpart. The exception to this will tend to be in the larger formats like rectified 60x60 although the gap is now closing. Ceramic tiles tend to be more affordable at 30x30-50x50 sizes and simple random formats In our experience however once you are looking at lenghts over 60cm. or random lenght limestone tiles it is hard to find alternatives although this may soon change...

Terracotta Tiles: Our current experience is that Ceramic/porcelain tiles have replaced machine made terracotta tiles for those who want an earthenware look but for the hand made terracotta tile look there is no satisfactory substitute. A good Italian ceramic tile will generally cost more than a basic Spanish machine made terracotta tile, but by the time you have costed the extra materials and fixers time, the difference does tend to disappear, plus the fact that smooth terracotta tiles tend to be less forgiving than hand made tiles.

Slate Tiles: Alot of ceramic/porcelain slate tiles can look like the proverbial dogs dinner and if its actually cheaper than natural slate tile, it most definitely will. Our Indian Autumn tile has the riven texture of slate tiles but the yellow buffs of Sandstone tiles.We stock it because it is the kind of colour that cannot be achieved reliably in natural slate tiles.Some slate is vulnerable to scratching,particularly the smooth calibrated Brazilian slates,which we would only really recommend for bathroom duty.The more rugged Chinese Slate or Indian Slate conceals it better.For heavy duty commercial applications where porcelain tiles would be more appropriate we can supply simple plain colours to order.

Tiling in demanding locations

1. Commercial applications

For information about commercial areas we will normally require fairly precise information due to the wide variety of requirements. Please contact a member of staff for full details.

2. Wet areas and Bathroom Tiles.

As a general rule of thumb we make a distinction between tiling around general wet areas (e.g. bathrooms with or without showers) and more demanding applications such as dedicated or enclosed showers. Most of the products we sell as wall tiles including e.g., Mexican and Moroccan wall tiles, and most natural stone tiles are suitable for tiling in general wet areas. The only proviso is that the area is correctly prepared to take tiling: A good quality adhesive is used and the adhesive is applied as a solid bed without voids behind the tiles. Where possible, a grout with waterproof additive should be used and, where appropriate, a sealer should be applied to the tiles. Joints should be finished with a silicon sealant.

Dedicated showers create a more demanding environment for tiles. To this extent we may not recommend certain more rudimentary handmade tiles and may suggest that extra precautions be taken with most natural materials. Modern power-showers can generate extreme demands on tiles and therefore we may be cautious in our recommendations about what tiles should be used and, we also recommend that every precaution be taken to ensure that the whole system doesn't fail. The old adage that a fault costs five times as much as doing the job correctly to start with is as true about showers as it is true about anything.

Our general guiding principle with showers is to suggest that customers ensure that the structure is as waterproof as possible prior to tiling. It is very easy to install some perfectly adequate tiles onto a porous plasterboard background and for water to find its way through a pinhole in the grout round the back of the tiles and for the plasterboard to break down and the tiles to eventually lift off. There are a number of ways of avoiding this scenario:

1. Tile boards
   There are a number of proprietary boards designed to receive tiles. These are variously known as 'aquapanel', 'weddiboard' and 'tilebacker board'. The advantage of these materials is that they are specifically designed for tile installation and are dimensionally inert in moist or wet environments.
2. Waterproof membranes
   There are a number of products available using acrylic-based flexible coatings and polyester mesh. The advantage of these products is that they can be applied over existing boards. In principle one could use these products to create a waterproof cardboard box. For more information, contact BAL on 01782 591 100. A kit for an average shower is about £60. If this is used with BAL adhesives and grouts BAL will offer a 10 year guarantee on their products Adhesive manufactrers are notoriously circumspect in their recommendations, but at the very least in the event of a wet area failure one should be entitled to an independent inspection. BAL currently market a product called Mosaic Fix which, despite it's name, is in fact a white, waterproof, flexible adhesive which will fix mosaic, wall tiles, porcelain and stone tiles to all standard bathroom surfaces, coverage is approximately 8-1m per 20kg bag. £26 +VAT. Highly Recommended.
3. Marine-ply
   This is more suitable than most generic boards but could possibly warp in certain high humidity situations.
4. Concrete block/rendered walls
   These walls will present less of a problem but it's unlikely that they will constitute all the walls in the area. In addition to the above, one should take the usual precautions about using a solid bed waterproof adhesive, waterproof grout, sealants where appropriate, and silicon joints, again, where appropriate. Ceramic tiles should need little in the way of maintenance once installed. Natural materials should be cleaned with 'easy-care'. In the event of any sealant failure due to either under-application or long term wear and tear, then more sealant may be required. Hard water build-up can be dealt with using Lithofin 'power-clean'.

3. External

Most of our external quality products are relatively slim, usually between 20-25mm thick. This means that they have to be fixed using standard tiling techniques onto a prepared surface. They cannot be installed like paving slabs, York stone, brick on edge or any other conventional exterior paver that stays in situ largely by virtue of its own weight.

In terms of general suitability the main concern is frost resistance. There are two basic categories here, namely: those that have a manufacturers' guarantee and those which don't have such a guarantee but where one can point to widespread general use.

In the first category one would include vitrified porcelain-bodied floor tiles and certain stones. Porcelain floor tiles are either glazed or unglazed and because of their very low porosity (less than 0.5%) both from above and below they are normally supplied with an EN202 porosity resistant qualification. (Their slimness also means that they are suitable for roof-terraces and not just patios and gardens.)This means that even if the tiles are not fixed properly the worst that can happen is that the tiles will lift, but they will remain unaffected by the frost. Certain stone tiles do come with manufacturers' recommendation about external suitability but in our experience this is usually prefaced with the recommendation that they are a certain thickness (maybe 3 or 4cm) or with a surface finish. We would always wish to discuss individual requirements with stone.We can also supply Indian Sandstone in random formats as a York Stone equivalent at 25.00/m2.

In the second category come products such as slate. Whilst some slate tiles are more durable than others, there is a general history of their use outside and we have been selling them without problems for many years. In sheltered settings we would recommend most of the slate tiles, for more demanding applications, consider Jade, Pale Quartz, Chinese multi-colour, Black Flags and some of the new Brazilian material. Our English Terracotta tile also falls into this category.

All tiles should be fixed with a solid bed of adhesive and with a fall to allow natural drainage. Adhesive manufacturers do make general best practice recommendations for fixing to asphalt roofs, but it should be noted that they usually qualify this, pointing out that the wide variety in construction standards will preclude a guarantee. Nicobond's recommendations seem to us as good as anyone's.

4. Family kitchens.

We have noticed that some stone suppliers tend to classify all domestic requirements under the general heading "residential". In our view, residential requirements can vary quite widely and nowhere is this more true than with modern family kitchen floor tiles. Our inclination is to follow the old ceramic tile classifications and to distinguish between general domestic and heavy domestic/light commercial. The wear and tear, abrasion, spillages and repeated cleaning will give any stone tile a much harder time than in any other room in the house. To anyone looking for a stone kitchen floor tile we would make the following observations:

1. Have a look at the ceramic alternatives; it's not the real thing but it is impervious.
2. Have a look at slate tiles; they are darker but show less.
3. Be prepared to pay more for a harder stone tile that will scratch less.
4. Consider a mottled stone tile that will conceal day to day dirt.
5. Consider an aged or slightly distressed finish that does not need to look so perfect.
6. Be prepared to use neutral soaps to clean the floor and reapply surface polishes.

The advice above is given in good faith to answer F.A.Q.s, but we would always suggest you contact us about specific or significant details.

5.Under-floor and Under-tile heating.

Advice on the suitability of tiles in relation the both 'wet' or piped under-floor heating and electric under-tile heating is subject to a variety of opinions and one cannot rely on a definitative statement from the British Standards Institute.We have found that the best advice is available on a (lengthy) pdf document at the Tile institute www.tiles.org.uk .It does not however resolve the issue as to how far the aesthetically more pleasing de-coupling mat is an alternative to mid-floor(as distinct from perimeter) expansion joints.At the moment we would rather customers contact us for advice.You may also wish to contact www.hot-floors.com for advice on the more straightforward electric systems.

Sealing Natural Materials

There are three main product categories where sealing is required: Limestone tiles, Slate tiles and Terracotta tiles.

LIMESTONE TILES: Stone is a delicate material that need careful sealing. Thick varnishes and laquers will destroy its aesthetic subtlety. Most stone tiles are therefore sealed with an impregnating oil that soaks into the stone and cures without any substantial change in colour or surface appearance. We currently use a product called Stainstop. This will provide and effective barrier to oil and water-borne stains. We have successfully used this on a pale cream limestone worksurface test area for several years without any apparent stain. It should be pointed out, however, that spillages are wiped up and not left on the surface. This process is usually sufficient for dense stone or stone that is not subjected to high levels of traffic.

Stone tiles often have small pin-holes and open fissures as part of its natural texture. This texture will tend to accumulate grit as part of the natural wearing process. To reduce the effects of scuffing and heavy traffic, we normally recommend that an additional coat of Care Seal is applied. This is water based and easy to reapply in areas of high wear.

Coarse textured or softer stone such as Cotswold stone,sandstone or antiqued travertine benefit from the additional surface protection of a stone wax.

A neutral cleaner should always be used with stone, such as Easycare.

Stone tiles can often arrive on site still damp from the production line. It should be allowed to dry prior to sealing.

SLATE TILES: Slate tiles are a more rugged material than limestone tiles and the sealing process is generally less complicated. It is lower porosity than limestone and a surface protector is generally sufficient. We currently recommend either Slateseal or Ironwax Satin. These will give a slight gloss to the floor but, unlike limestone, slate does not get a 'toffee apple' appearance when sealed with a surface sealant. Slate tiles are very forgiving in use but we always recommend the use of Easycare with any natural material.

TERRACOTTA TILES: Terracotta tiles are a more porous material. The traditional impregnating fluid is boiled linseed oil. This soaks into the product, hardens, reduces porosity and generally enhances the colour and appearance of the tile. Linseed oil can be initially diluted with white spirits or used neat. You normally need to apply more than one coat  and sometimes as many as four to saturate the tile.The number of coats can vary from tile to tile,so do not allow any excess to dry on the surface. If it looks like it is not soaking in do not assume that it will.Remove,disperse or thin with a cloth and/or white spirits.Dispose of oily rags carefully, they can combust.

Linseed oil on its own is not enough. You will need several coats of wax as part of the installation process. Reapplications of this wax will depend on levels of traffic but the process can be simplified by using a liquid wax such as Terracotta Sealer. Regular cleaning should be with Easycare or Waxwash.

Terracotta tiles are often soaked after production. Tiles MUST be dry prior to sealing. This is absolutely critical in sunrooms or where there is underfloor heating.

We normally supply Mexican Saltillo tiles with their own proprietory sealers.

• Recommended Sealants for Terracotta Tiles,Limestone Tiles and Slate Tiles.

Lithofin Stainstop:Limestone tiles,Slate tiles,Casbah tiles,Travertine tiles and worktops.Lithofin Caresheen is also suitable for Limestone tiles,Slate tiles,Casbah tiles,Travertine tiles where a little sheen can make the surface easier to clean.Lithofin also recommend that for Natural Stone tiles,Travertine tiles,Limestone tiles,Slate tiles and Casbah tiles that an appropriate neutral cleaner such as EasyCare is used to preserve the longevity of the treatment.

Where a colour enhanced appearance is required on Limestone tiles,travertine tiles and various tumbled or antique marble tiles then we would recommend Lithofin Stainstop Plus or LTP Colour Enhancer.

For traditional terracotta tiles the usual treatment is Linseed Oil and Beeswax,but it is possible depending on the porosity of the terracotta tiles to use a Cleartone or Mattstone Oil and finish with an Ironwax Satin treatment.Some rougher or more porous limestone tiles or Cotswold stone tiles can also benefit from a beeswax finish.

Riven slate tiles can be treated like limestone tiles but as the overall aspect of slate tiles is usually a bit more rugged we normally suggest a more viscous treatment like Slate Seal.Where a lighter look is required for the slate then a water based treatment like Ironwax Satin may be preferred.