SUBSOIL
As with all rigid tiles, a firm subfloor is required for the laying of a natural stone floor. A smooth, level sand-cement screed is the ideal surface, but suspended hardwood floors needn’t be a problem as long as they’re reinforced. Normally waterproof plywood screwed to existing floorboards on 200mm centers is sufficient, but if in doubt it is best to seek professional advice. If levels are a problem, the plywood can be bolted directly to the joists (if the joints between the sheets are supported by notches at 250mm intervals)
FACILITY
Tiles must be laid with an adhesive. The adhesive bed should have an average thickness of +/- 5mm, but should never exceed 10mm. When laying over suspended wood flooring or using any form of underfloor heating, a flexible additive must be used with the adhesive and grout.
In all cases, the back of the stone should be ‘buttered’ before it is set to provide a key. If the tile is too dry, it must first be moistened with water to improve adhesion. When laying light colored or fine limestone, white adhesive or white cement grout with sand/semi-dry cement should be used.
SEALING
All natural stone is porous and therefore we always recommend that a sealer be used.
The amount of sealer to use depends on the porosity of the stone. It is always best to apply three coats, the first of which should be applied before the grout. After grouting, a second and then a third layer must be applied. There is a saturation level beyond which the stone will not take any sealer. Over-sealing will leave scratches on the surface that are difficult to remove. If scratches appear on the surface, they should be cleaned with a dry cloth.
Sealers always work best when applied to dry stone. It is important to wait until the stone is completely dry before beginning to seal the floor.
GROUT
A cement based grout should be used. It is important to use the correct color of grout, usually light beige or light gray is the best option. We recommend that the grout be specified to be as close to the color of the stone as possible. If the correct shade is not available on the shelf, a darker color should be mixed with white. When grouting limestone, it is important to work very cleanly, preventing any residue from drying on the surface of the stone. This is important because the normal way to remove laitance is with an acid, which would attack limestone.
The width of the joint is a matter of taste. As a general rule, a wide joint (6 to 10 mm) will give a more rustic appearance than a narrow one (2 to 3 mm). If you are in any doubt about the color of grout to use, we recommend that you ask the installer to prepare some grout samples for your approval.
CARE AND MAINTENANCE
Once the floor has been laid and sealed, the care and maintenance required is low. The floor should be cleaned with a recommended stone cleaner or with water. It is vitally important that any cleaner that contains detergents is never used; detergents will remove the sealer from the floor. For daily use we recommend the Lilothin Easycare cleaner.
A sealer will protect the floor from most stains, but care should be taken with oil and acid based products. Spills should be cleaned up as soon as they are detected. Any stains that do occur can be cleaned with an intensive stone cleaner.
Every 5 to 6 years (depending on wear and tear) the floor will need to be resealed. This is normally done by a tiler.
WAXED / POLISHED
The appearance of some stones can be enhanced by adding a shine to the surface. There are several ways to do this:
– Using a Lilothin product such as Careseal or Multiseal. This is applied with a mop and will give the appearance that the floor has been polished. To maintain the finish these products create, treatment should be done every 2-3 months (depending on wear).
– It is also possible to polish/wax some floors. This is a more labor intensive method than the previous treatment. It is recommended that you have a tiler perform this process.
