A Guide to Terraces

A Guide to Terraces

There is a very wide range of tiling products currently available on market and their use is conditioned by their different characteristics. The classification of tiles can be diverse and sometimes confusing. At Metroclean, we have classified tiles through our experience working in southern Spain. Although the manufacturing process in tile production is very similar, we distinguish two separate groups: ceramic and terracotta. Identifying these groups is important for their subsequent cleaning and sealing treatment.

Ceramic Tiles

Ceramic tiles are very common in southern Spain and are the easiest stone surfaces to maintain.

Ceramic tiles are flat, thin stones predominately made of clay and silica. They are generally used to pave floors and cover walls and façades. Ceramic tiles are frequently found in bathrooms, kitchens and terraces.

Ceramic tiles are commonly manufactured by a two stage firing process: once the raw materials have been ground and molded, they are fired through ovens to dry them out. The tiles are then glazed and follow a secondary firing process to produce the finished product.

They have a fine surface silica glaze (usually with a thickness of between 75 and 500 microns) and this not only provides considerable aesthetic appeal but also gives the tile some interesting mechanical properties such as impermeability and protection towards erosion.

The surface glaze on ceramic tiles allows their cleaning and maintenance to be fairly straightforward. Excess cement and plaster can easily be removed with products such as The Terrace Warrior and, on a daily basis, the tiles can be wiped down using general purpose cleaners and dry paper towels. For floor areas Metroclean would recommend Neutraclean which contains properties which allow the liquid to evaporate from surfaces thereby eliminating streaks and residue. On coastal areas, terraces are often covered in white, salt deposits and, for ceramic tiles, this can be easily removed with The Terrace Warrior. The big advantage of ceramic is the fact that the glaze prevents the salt from penetrating the surface.

Tiles are produced either through extrusion or press molding. The extrusion process involves forcing the raw material mix through an orifice (or die) to achieve the flat shape and then passing the extruded material through rollers to achieve consistency in thickness. Press molding involves passing the raw material through hydraulic presses which stamp out the tiles producing products with the adequate thicknesses and shapes in one pass. Ceramic tiles produced by press molding generally have slightly curved edges.

The tiles come in a range of different colours and effects. The surface finish can be completely flat with a high gloss finish or can have patterned effects which are slightly matte. High gloss tiles are used for covering walls while matte finishes are predominately used for non slip flooring.

Terracotta

Terracotta tiles are widely used in the Mediterranean and give warmth and atmosphere to internal and external living areas.

Terracotta tiles have considerable rustic charm and can be categorised in terms of terracotta brick and terracotta clay. Terracotta brick is frequently used for entrances, driveways and sometimes internally for flooring in country homes. The fine terracotta clay is very popular for apartment terraces.

The main difference between terracotta and ceramic tiles is the glaze. Terracotta tiles are normally produced from a single firing and, although this gives considerable cost benefit through the manufacturing process, it means that the tiles have no inherent protection and are very susceptible to aesthetic damage.

In terms of cleaning, the terracotta brick is perhaps more user friendly than the clay as the brick contains many colour and surface imperfections which add to the charm. The brick is usually slightly softer than the clay meaning that a thin layer of the top surface can be easily removed through chemically etching leaving a perfectly clean finish.

Terracotta clay is the most difficult tile to clean. Terracotta is very porous and readily absorbs grease, moisture, salt and dirt. The surface finish of terracotta clay is less forgiving as it is very fine and uniform in colour resulting in an inherent emphasis of minute imperfections.

Ideally, terracotta tiles should be sealed prior to installation to prevent the subsequent, inevitable staining. However, sealants are expensive and can be prone to erosion on external areas due to excessive rain or sun. There are a wide range of sealants on the market all with varying effectiveness, including: water based, solvent based and resin based treatments. The appropriate treatment to apply will very much depend on the type and location of the tiles.

Removing grease from terracotta tiles is most effectively done using a sodium hydroxide based cleaner such as The Grease Guzzler. The Grease Guzzler breaks up greasy barbeque stains and holds them in an emulsion on the surface allowing them to be easily removed with water.

Salt, dirt and cement is most effectively removed using The Terrace Warrior. The Terrace Warrior contains surfactants which penetrate through the pores of the tile and actively lifts out grime.

Efflorescence

One of the biggest issues when dealing with terracotta tiling is efflorescence. Efflorescence is when moisture evaporates out of the tile and leaves a salt deposit on the surface. Terracotta tiles are like sponges and, when unsealed, frequently hold a high water and salt content which filters out leaving unsightly stains. Efflorescence can be caused by two means: either from underneath the stone where the cement has been mixed with sand from the beach; or, externally through sea air and moisture. Using products such as The Terrace Warrior will relieve the problem but often the efflorescence will repeat itself until all the salt crystals have evaporated on the surface and in some cases this can take months.