Installation
- Prior to the installation
- Preparation
- Installation on a cement drainage layer
- Installation on a concrete base
- Installation on tile supports
- Installation on mortar sacks
- Joints
1. Prior to the installation
Make sure that the connection of the tile floor to the façade of the house is lower than the level of the damp course in the wall. Stagnant water is natural stone’s worst enemy. For this reason, thought must be given to good drainage from the start. A porous foundation is very important. A slope must be installed to enable water to run off as much as possible, 1 to 2 cm per metre as a rule. The slope must be angled so that the water is carried away from the building.
When making the connection between the façade and the tiles, an expansion joint should be installed. The natural stone will expand in the sun and contract when cooling down or in frost. When the expansion joint is forgotten, the expansion and contraction of the tile cannot take place naturally and the tile will eventually break. Thus foresee an expansion joint between the terrace and the facade. The expansion joint should be moisture-proof and elastic (frost-resistant kit or profile). Always adhere to the following rules regarding expansion joints for large terraces: Expansion joints across the stabilised sand and mortar bedding are indispensable:
- Dark shades exposed to the sun: terrace greater than 35m² or a length of more than 5 m.
- Light shades exposed to the sun: terrace greater than 35m² or a length of more than 6 m.
- Dark shades not exposed to the sun: terrace greater than 35m² or a length of more than 8 m.
- Light shades not exposed to the sun: terrace greater than 35m² or a length of more than 10 m.
Please note: for BELTRALINEA strips regulations are more rigid. We recommend to consult the specific guidelines on www.beltralinea.co.uk.
2. Preparation
Never install tiles one against the other. Do not slide the tiles over each other or they may become scratched. With the exterior installation of natural stones, do not forget to take into consideration that, apart from the mechanical tensions to be imposed upon them, the most important influences on tiles are due to the climate. In particular, the sudden changes from damp to dry weather or from freezing to thawing conditions. In addition, various human activities, such as pedestrian and vehicular traffic, sudden impacts, etc., will have an effect on the exterior floor.
When working with slate and quartzite, the back of the tiles must be coated with a vinyl solution, composed of BELTRAMIX, white sand and white cement. This must be applied at least 24 hours before installation.
3. Installation on a cement drainage layer
For a terrace, the foundation must be laid under the frost line, around 40 cm below the level of the floor.
- A hardcore drainage foundation, firmly installed and dammed, of around 20 to 30 cm
- Granulated concrete of around 15 cm.
Composition: 150 kg cement per m³ of granules 8/22 or 10/20 - Stabilised sand bed of around 5 cm.
Composition: washed river sand 0/5 or 0/7, mixed with white cement, slightly damp and well tamped in. Proportions: 9 parts sand to 1 part cement. - Mortar bed of maximum 3 cm. The tiles are laid fully in the mortar, not ‘dotted’.
Composition: white sand 0/2 mm mixed with white cement. Proportions: 4 parts sand to 1 part cement. - Tiling
4. Installation on a concrete base
Avoid this method of installation because concrete holds stagnant water, which can freeze within the terrace. Additionally, concrete has a greater shrinkage coefficient which, in the long term, can cause cracks in the tiles. If, nevertheless, you have a concrete base structure, proceed as follows: Lay a drainage mat on the concrete (e.g. a Trauba-plus from Schlüter). You can choose between 2 options to proceed:
A. Lay a reinforced bed with a minimum thickness of 5cm. Allow this top layer to dry thoroughly (minimum 28 days). After this, coat the calibrated tiles (BELTRALINE) with a suitable adhesive (BELTRAFLEX) and lay them on the reinforced bed. The main advantage of this method is that the terrace has no contact with the base concrete and can therefore react to changing weather conditions.
B. On top of the drainage mat you continue with the traditional way of installing: stabilised sand bed, mortar and tiling (see 1)
5. Installation on tile supports
This method is often used for roof terraces and balconies. However, it is also suitable for ground floor terraces provided it is not used by vehicles. N.B: for this method of installation the natural stone must have a minimum thickness: certainly no thinner than 3 cm, depending on the type of material. The base must be completely level. Any unevenness can be corrected with roofing felt. The tile support determines the width of the joint.
6. Installation on mortar sacks
This method can be used in the same situations as for installation on tile supports. The tiles are laid on plastic sacks filled with mortar. You can decide for yourself the width of the grouting (minimum 4 to 5 mm). By using spacers, the perfect grout width can easily be controlled. As long as the mortar in the sacks does not harden, the tiles can be laid and levelled.
7. Joints
Never install tiles one against the other. With smooth surfaces, like Blue Stone, the joints can be rather narrow (4 to 5 mm). However, most natural stones are not so uniform and joints from 8 to 10 mm are not exceptional. For terraces, such a joint is necessary to enable the process of expansion and contraction to take place. Finally, grouting the joints would in most cases be impossible, as too much cement remains stuck to the rough surface. For this reason a grouting tool (thinnest: 5 mm) should be used. Avoid installing tiles with irregular or offset joints. Some materials in our range are sufficiently thick and hard wearing to allow for irregular or offset joints.