Which Tiles Are Suitable For Outdoors?

This question has different answers depending on the context of the situation. With the trend towards extra thick (usually 2.0 cm) porcelain tiles, many people are unsure of what answer to give.

Hopefully we can shed some light on this. 

Firstly, it is worth noting that while any tile can actually be physically installed outside, it is a combination of the uses and conditions which will dictate which ones are best suited.

Surviving The Elements - Porcelain or Red Body?

The vast majority of floor tiles fall into one of these two categories. It is useful to be familiar with the crucial difference between these types of tiles, and that is their water absorption characteristics.

The clay of a porcelain tile has a far lower water absorption rate than a standard red body tile, by definition less than 0.5%. Consequently, in freezing weather, there is a much lower chance of the porcelain tile cracking under the pressure of expanding moisture content.

It is important in this context, because although glaze on the surface of any tile should be impermeable, any moisture that finds its way into the body of the tile comes either from underneath, or through flaws in the grouting. This is far more likely to happen outside than indoors.

Conversely, some red body tiles, especially wall tiles, are capable of absorbing up to 20% of their own weight in water. These tiles are not as likely to survive constant exposure to sub-zero temperatures for long.

Therefore, in northern Europe, only porcelain tiles should be used in areas exposed to the elements. This is true whether the tiles are being installed on the ground, or on a wall.

Furthermore, porcelain tiles are significantly stronger than their red body counterparts. They are fired for longer, at a greater temperature, and with a different, higher standard, of clay. As it is often the case that tiles installed outside are subject to greater pressure, such as that from parked cars, it makes sense that only the toughest ones are used.

 Image : Betria Tile 

20 mm Thick

In recent years there has been a trend in the tiling industry towards thicker glazed porcelain tiles. It is these which are what many people now refer to as “outdoor tiles”.

The majority of these are 20 mm thick, making them exceptionally durable. It is possible to install these on a bed of sand and cement, much like natural stone or cement pavers. This has enormous cost saving implications, bypassing the need for a concrete base.

Because these floor tiles are of uniform thickness, and have straight edges, they can also be mounted on pedestals, in areas of lighter traffic.

Image : The Aston Perla Floor Tiles 

Inside Out

One of the huge advantages of a porcelain floor tile is that you can provide a seamless transition from indoors to out, which works best when you can throw open large patio doors. It makes for a smooth flow from your garden to your kitchen – affording you the ultimate in outdoor living.

Of course, this can be done with natural stone, however you are restricted in terms of styles and there may well be problems caused inside the house by the thickness of the stone.

With porcelain tiles, there is a seemingly infinite number of styles, shapes and size.

Slippery When Wet

It is highly recommended that tiles with a high level of slip resistance are used outdoors. Aside from the obvious danger when the surface is wet from rain, over time the surface can become greasy from leaves, moss and other natural debris that is found in the environment.

It is important to regularly maintain the tiles to avoid a build up of organic materials.

Many porcelain tiles now come in both an antislip and regular version, so it is possible to install one inside the house and continue the same pattern outside but with a much safer surface for less pleasant conditions.

Image : Atelier Wood Effect Floor Tile 

Summarising Outdoor Tiles

An outdoor tile can be any porcelain tile with an appropriate surface. They are exceptionally strong and frost resistant.  2 cm thick porcelain tiles can be installed like natural stone slabs in a bed of sand and cement, without the need for a concrete base or screed. It is important that you ensure a suitable slip resistance for the area in question.