Sealing & Laying Encaustic Tiles
How our encaustic cement tiles are made
Our encaustic tiles are made by a family of artisans according to a tradition that goes back over two centuries. The top layer of each tile comprises a mixture of cement and ground marble. These are mixed with the colour and poured into a mould. The pattern is determined by a 5mm template. The complexity of the template and the number of colours chosen determines the final price of the tile.
The lower layers of the tile are then added. These are made from sand and cement to form a solid base. Finally, the slab is pressed with a hydraulic press and removed from the mould to mature and set. The tiles are not kiln-fired, but left to dry in fresh air for 21-28 days.
Take a look at our range of Encaustic tiles.
Laying encaustic tiles
1: Prepare a perfectly level surface in concrete or self-levelling screed/cement, 20mm below the line of the intended floor height.
2: Wait until the floor is completely dry before placing the tiles.
3: Place the tiles using separators if desired. Leave approx 2-3mm between each tile to allow for irregularities. If you choose a carpet-style pattern, you must start with the outside of the main pattern and move in, before placing the border which can be resized without disrupting the main pattern.
4: Clean and dampen the underside of the tiles to remove dust. Apply glue evenly to the floor subsurface and the back of each tile, using a wide comb. A stronger cement-glue will be needed for tiles that are going on the wall, or behind the oven. We can advise on this. Recommended adhesives are from manufacturers Ardex, Weber and Bal.
5: Lay the tiles, and press into place using your hands or a soft white rubber mallet. Do not use a hard rubber hammer as this could cause cracks.
6: Ensure tiles are completely level throughout the installation, as unevenness cannot be rectified later.
6.5: (Optional) Once the adhesive is perfectly dry, to protect the tiles against dirt and mortar stains, apply a coat of Protecer with a wide brush or roller. Some tilers apply a first coat of sealant at this point. If your tiler does this, the tiles must be left to dry thoroughly before grouting. The floor can be protected with floor protector or cardboard until it is ready to grout.
7: Grout the tiles. Grout should be approx 2-3mm wide. Any wider or any narrower and the pattern may be disrupted. Use a spatula to spread the grout and immediately remove any excess using a damp cloth. Do not use chemical cleaners to remove excess grout. Never use coloured grout, as the pigment could contaminate the tiles.
8: Clean the floor. Remove any cement residue or stains immediately, using water and a PH Neutral soap. Finally, rinse with warm water and dry with a liquid vacuum cleaner or cloth. Never use cement remover, strong detergents or bleach as these will damage the tiles. Paint-stains or hard cement spots can be delicately removed with waterproof sandpaper grade 200 with water, or Scotch-Brite. The tiles should be allowed to dry and not be walked on before they are sealed. Cement tiles should never be treated with oil.
Protecting encaustic tiles
First, ensure the floor is perfectly dry. Tiles need to breathe after laying to allow any moisture to evaporate. If a newly-tiled floor is protected too soon, humidity will get trapped and damp spots may appear. Sealants will not protect a damp floor.
Seal your floor
The floor must be completely clean and dry before you seal it. The floor must then be sealed with protector such as Bellatrix (available in a choice of matt or satin finish) with a brush or short-fleece roller. If using Bellatrix, shake the can before and during use. Then make sure that the tiles and grout are completely clean before you apply the Bellatrix, and that they are kept meticulously clean throughout the installation process as any staining before sealing will be hard to remove. An alternative to Bellatrix, available in smaller tins, is MN Stainstop. The sealant should be applied in thin layers until the floor is covered, and any excess left on the surface after 15 minutes should be wiped off to ensure an even finish. The tiles are porous so the sealant will be absorbed. The sealant should be left to dry for 24 hours. For a more brilliant finish, the floor may be waxed with Cera Noble Liquida, applied thinly with a soft cloth. It is not usually necessary to reseal the floor, although you may wish to do so after two or three years.
Ongoing protection and maintenance
Scrubbing with PH Neutral soap such as Marsella floor-scrubbing soap and then waxing is the traditional and most common protection for cement floors. These products protect the tile and bring out the colours. Use a glassful diluted in a bucket of clean water to both clean and wax to restore the shine. Never use bleach, acidic or alkali products (including strong detergents) as these will damage the tiles. After cleaning with PH Neutral soap it is also possible to use a Liquid Wax, such as Cera Noble Liquida.
Cutting the tiles
Cement tiles can be cut to fit with a diamond-blade angle grinder. Tiles should be moistened before cutting.
Installing cement tiles on suspended timber floors (including floorboards)
It is essential that you consult a competent builder. However, assuming that your floor joists are strong enough and non-flexing, you can lay tiles on a wooden floor. Flexible adhesive and flexible grout should be used and the wooden floor overlaid with plywood at least 3/8in (approx 10mm) thick. The plywood must be screwed down in a grid-pattern at regular 150mm intervals. A fleximat may also be placed on top of the plywood (optional). In rare cases where joists are weak, it should be possible to strengthen them in order to lay tiles. Our floor tiles are 22mm thick. However, it is possible to get them made to a thickness of 18mm. Therefore, when laying cement tiles on a wooden floor, the floor level will rise by approx 32mm, or 28mm if using thinner tiles. Thinner tiles, while they may be used on floors, need to be laid with more care. Again, please check with your builder.
Using underfloor heating with encaustic floor tiles
Underfloor heating is the perfect choice for use with our cement tiles. Cement conducts and retains heat brilliantly in the winter (making it economical, too) and keeps cool in the summer. There is no problem at all with heat-transmission unless you are using tiles of 42mm or thicker.
There are two kinds of underfloor heating: electrical heating or the so-called 'wet system' which uses hot water fired from your central heating system.
Electric-powered underfloor heating
Heating wires can either be set into screed with a minimum depth of 50mm, or alternatively a 200W under-tile heating mat can be used, which the cement tiles sit directly on top of. Screed is recommended for really thick tiles, such as flagstones.
Wet system
As long as you are tiling on top of a solid floor there is no problem at all. Only when tiles reach 42mm in thickness could there be any problem with the heat getting through.
In both cases it is important to check that the adhesive used is suitable, ie will not make a smell when heated up. The use of a special elastic cement adhesive and grout is required. Underfloor heating companies, such as those linked to above, will be able to advise on suitable products.
It is important that the substrate below the tiles is completely firm and unflexing. Please ensure your tiler has experience of tiling over underfloor heating and uses suitable products and procedures.
Using encaustic tiles in the bathroom
Use Bellatrix before grouting and, after grouting, clean with a PH Neutral Cleaner or wipe with a dry microfibre cloth. After grouting, once floor is completely dry, apply another coat of Bellatrix and, if desired, a coat of wax such a Cera Noble Liquida. Maintain with Cerabric and Liquid Wax as recommended above under "Ongoing protection and maintenance".
Tiling hearths and fireplaces
Care should be taken when tiling around fireplaces. Tiles must be kept at least 300mm away from direct contact with flames or the heat source. Please call us for more information.
Laying encaustic tiles outside
Because they are porous, encaustic cement tiles may crack or chip slightly as a result of damp and frost. They may also fade in the sunlight and rain - although we are thrilled to hear that a collection of Alhambra's authentic Spanish tiles, installed in 2014, are still 'as new' - please see our Case Study, 'Encaustic Tiles in a Garden'. However, whether or not you use encaustic tiles outside may still depend on how rustic a finish you require. If you want to keep a glossy, perfect finish, we do not generally recommend them for outdoor use in exposed areas in cold countries.
If you like the rustic look
If, however, the tiles will be sheltered (for example on a balcony or walled garden) or you live in a warm climate and you like the mellowed look, you may protect your tiles with Protecer (by immersion before laying) and then Bellatrix which is suitable for both internal and external use. You might also consider using reclaimed encaustic tiles outside.To avoid problems associated with a cold climate you should ensure that tiles are laid on a completely waterproofed concrete screed, on a gradient sufficient to drain water quickly. The tiles must also be laid with a double spread of adhesive to prevent pockets of water from forming beneath. The adhesive must be suitable for outdoor use. Grouting must be maintained meticulously to avoid water-infiltration. You may also wax the tiles regularly.
Also, do not place encaustic tiles under an oak tree as the leaves contain tannin which will stain the tiles, even once sealed.
Drying times
How long tile adhesive, cement or water from cleaning will take to dry will depend on a number of variables such as room temperature and make of products used. However, as a rough rule of thumb:
New cement floors: leave to dry for at least six weeks.
Cement-based quick set tile adhesive - please seek advice from your tiler or the manufacturer.
Other tile adhesives: check with manufacturer - could be as much as one week, and tiles should not be grouted before the adhesive has completely dried and cured. The screed/adhesive needs to dry through the tiles. If the tiles have been pre-sealed (some tilers prefer this method), the screed/adhesive will need to dry through the tile-edges and gaps between the tiles pre-grouting, so the process may take longer.
Soap and water (if tiles cleaned before sealing with soap and water): probably two days - check with a competent tiler. Some tilers prefer to clean with a dry microfibre cloth so as to eliminate the drying-time.
Grout: allow around 48 hours to dry - but always check with your tiler as grouts and conditions will vary.
Sealant: At least 24 hours between coats. Always apply the second coat thinly and wipe off any excess for an even finish.
Restoring Reclaimed Encaustic Tiles
Our reclaimed tiles need to first be sanded/polished with fine sandpaper. They can then be cleaned with a product such as Sanigel or MN Powerclean before finishing with Bellatrix or MN Stainstop. Old treatments can be removed with Sanigel.
Sealing and Maintaining Encaustic Tiles in a Commercial Premises
Special care needs to be taken when sealing a shop or restaurant floor. It is recommended to use at least two coats of sealant. After sealing, it is very important to use the correct PH Neutral cleaning products daily, using a floor polisher with brushes. The dirty water should be Hoovered up with a wetvac as soon as possible. The tiles can be further protected with Cera Noble Liquida.
Further information
For more information on Monestir products such as Bellatrix, Protecer and Cerabric or other advice on any aspect of protecting and maintaining encaustic or terracotta tiles, please contact Monestir, or Extensive. For other questions on installing encaustic or mosaic tiles, please contact us.
The above information is intended as a guide only. All tile installations should be carried out by a competent builder or mason. Alhambra Tiles cannot be held responsible for any problems with or following the installation of any tiles bought from us.