Tiling on facades

Common issues and queries you can face

Thumbnail

Water ingress from the joints

Most cement-based products including grouts and adhesives are porous to some extent. Joints between tiles are not 100% waterproof, water can enter the joints through capillaries or micro-cracks in the joints, causing the tiles to de-bond. 

These pores allow water to permeate through the grout into and between the adhesive and the substrate. 

Exterior tiling is exposed to more aggressive conditions than interior tiling. The effect of sun, wind, rain and frost shortens the life of the covering.

Thumbnail

Water expands on freezing

Pores in the grout will be vulnerable to frost damage. Voids behind the tiles provide a place for water to gather and then to freeze. This may happen in case no back-buttering was admitted or if tiles have not been pressed enough to the tile adhesive. 

Water expands on freezing and when this happens in a confined space, it could generate enormous forces. In cold climates the cumulative effect of repetitive cycles of freeze (expansion) and thaw (contraction), cause cracks in the adhesive which can reduce bonding dramatically

Thumbnail

Weathering effects (elevated temperature)

With temperature variations, different materials expand and contract at different rates. This results in stresses between the different materials, which could cause de-bonding and result in delamination. 

Failure occurs when a ceramic tile expands and contracts with moisture and temperature at different rates than a concrete slab.

Step by step solution

weber solution

  1. Substrate preparation

    Organize the works so that tile fixing will not be performed on surfaces exposed to the sun. 

    Surface must be clean, dry, sound and free from dust, dirt, oil, grease or any contaminating material,...etc. 

    Use a concrete repair mortar to repair holes and defects. 

     

    Brick and block work 

    Allow at least 6 weeks before tiling, ensuring that the wall face is sufficiently flat. 

     

    Concrete 

    Allow at least 7 weeks before tiling onto new concrete to ensure that it is fully dry. 

    Smooth concrete surfaces may require additional priming with webercol prime. 

     

    Allowance for movement 

    Flexible fraction joints of 5 mm minimum should be incorporated every 3m horizontally and every 5m vertically.

  2. Tile adhesive

    It is important to select an adhesive with the appropriate level of flexibility to accommodate for the expected strains from either differential thermal or moisture movement and/or deflection of the substrate under load. 

     For façades, up to 6 m high, webercol flex, webercol max, webercol fast, webercol F1, webercol plus, can be used. 

     Use webercol flex for heights up to 28 m 

     Back-buttering method is mandatory to ensure full adhesion 

     Press well the tiles using a rubber hammer to ensure full transfer of tile adhesive with the substrate and the tile.

  3. Tile grouting

    It is recommended to have a minimum joint width of 4 mm around the tiles. Grouting should be done at least after 24 hours of fixing tiles, using weberjoint perfect or weberepox easy. 

    weberjoint perfect can be applied to a width of up to 20 mm. 

    weberepox easy can be applied with width of up to 10mm.

    Remove excess adhesive from the joints to ensure full adhesion and filling of the gaps.

     

    Important note

    It is advisable to use a flexible adhesive and a high-performance grout with for external applications.