How to Install and Maintain a Natural Stone Floor
Post Date: 20 Apr 2009 Viewed: 974
SUB FLOOR
As with all rigid tiles a firm sub-floor is needed for the laying of a natural stone floor. An even and level sand and cement screed is the ideal surface, but suspended wooden floors need not be a problem as long as they are strengthened. Normally waterproof plywood screwed down to existing floorboards at 200mm centres is enough, but if in doubt it is best to get professional advice. If levels are problem, plywood can be screwed straight to joists ( if the joints between the sheets are supported by noggins at 250mm intervals )
INSTALLATION
The tiles should be laid with an adhesive. The adhesive bed should average +/- 5mm in thickness, but should never exceed 10mm. When laying on a suspended wooden floor or using any form of underfloor heating, a flexible additive must be used with the adhesive and the grout.
In all instances the back of the stone should be 'buttered' before fixing to provide a key. If the tile is too dry it must first be wet with water to improve adhesion. When laying light colored or thin limestone white adhesive or white cement slurry with sand/cement semidry must be used.
SEALING
Every natural stone is porous and therefore we always recommend that a sealer is used.
The amount of sealer to be used depends on the porosity of the stone. It is always best to apply three coats, the first of which must be applied before grouting. After grouting, a second and then third coat should be applied. There is a saturation level beyond which the stone will not take any sealant. Excessive sealing will leave streaks on the surface which is difficult to remove. If streaks appear on the surface they should be wiped of with a dry cloth.
The sealers always work best when applied to dry stone. It is important to wait until the stone is completely dry before starting to seal the floor.
GROUTING
A cement-based grout should be used. It is important to use the right colour of grout, usually light beige or light grey is the best option. We recommend that the grout is specified to be as close in colour as possible to the stone. If the right shade is not available off the shelf, a darker colour should be mixed with white. When grouting limestone it is important to work very cleanly, avoiding any reside at all drying on the surface of the stone. This is important because the normal way of removing grout is with an acid, which would attack the limestone.
Width of joint is a question of taste. As a general rule a wide joint (6 to 10mm) will give a more rustic look than a narrow one (2 to 3 mm). If in any doubt over the colour of grout to use we recommend that you ask the tiler to make up some grout samples for you to approve.
CARE AND MAINTENANCE
Once the floor has been laid and sealed the care and maintenance required is low. The floor should be moped with a recommended stone cleaner or water. It is vitally important that any cleaner that contains detergents should never be used - detergents will strip the sealer of the floor. For everyday use we recommend the Lilothin cleaner Easycare.
A sealant will protect the floor from the majority of stains but care must still be taken with oil and acid based products. Spillages should be cleaned as soon as detected. Any stain that does occur can be cleaned with an intensive stone cleaner.
Every 5 - 6 years (dependant on wear) the floor will need resealing. This is normally done by a tiler.
WAXING / POLISHING
The appearance of some stones can be improved by adding a sheen to the surface. There are several ways of doing 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 the treatment should be carried out every 2 - 3 months ( dependant on wear ) - It is also possible to polish / wax some floors. This is a more labour intensive method than the treatment above. It is recommended that you ask a tiler to carry out this process.