The adhesive used to fix ceramic tiles on façades must withstand very demanding conditions. To withstand these conditions, a water and ice proof adhesive is necessary, with a good adherence capacity and flexible so that it can withstand any mechanical deformation and thermal expansion.
The grouting mortar must also be deformable and able to absorb any tensions that are transmitted to the ceramic coating.
Water, ice and thermal shock,… cause the tiles to expand and contract considerably, and this is transmitted to the adhesive.
Differential movements of the support can cause tension in the tile and the adhesive.
The larger the size of the tile, the smaller the joint arrangement between them and, consequently, if there is any deformation, the ceramic coating wears worse.
To withstand these conditions, a water and ice proof adhesive is necessary, with a good adhesion capacity and which is flexible so that it can withstand any mechanical deformation and thermal expansion. The grouting mortar must also be deformable, and able to absorb any tensions that are transmitted to the ceramic coating.
PREPARING THE SUPPORT
Check that the support is strong, perfectly set and clean of any dust, paint, oil….
Wet the support if it is exposed to sunshine and/or if it has to be very absorbent.
Check the smoothness of the support with a 2 m long ruler; any differences must be less than 5 mm; if necessary fill in any gaps with mortar.
Mix with a slow electric mixer (500 rpm), leave to stand for 5 minutes and spread VAT® SUPERFLEX / PAM® SUPERFLEX COMPACT / PAM® FLEX / VAT® FLEXIBLE / VAT® FLEX RAPID onto the support using a notched trowel. Use the Floating and buttering technique when the part is more than 900 cm2.
Press the tiles so that they form a solid surface, thus avoiding any gaps between the tile and support.
Leave a minimum grouting joint width of 5 mm between the parts. Do the pointing 24 hours later with BORADA® PLUS or BORADA® UNIVERSAL.
- It is advisable to assemble expansion joints every 30 m2 (small sizes) or every 60 m2 (large sizes), and perimeter joints on cornices, wrought iron raised parts, etc., and respect the building´s structural joints.
- Consider a good joint arrangement, if they are dark and/or have a high expansion coefficient.
- Protect the top edges of the render with metallic sections, guttering, etc., to prevent water entering the fixing layer and the support, which would cause the tile to fall away in freezing temperatures.
- For sizes over 2000 cm2 and/or weights over 40 kg/m2 mechanical anchors must be used.
- For applications where quick service is required, used VAT® FLEX RAPID.
- When fixing natural stone (marble, granite, slate) or artificial stone on façades, use VAT® FLEX RAPID.