For medium to large size tiles, for example, such as those with one side between 30 cm and 60 cm long, it is recommended to adopt class S1 deformable adhesives (for example KERAFLEX MAXI S1, which is classified C2TE S1 according to EN 12004). Their deformability may even be considered an added value in the case of tiles installed on deformable substrates, such as those waterproofed with MAPELASTIC system.
Do the tile joints on terraces need to be waterproof?
It’s not a requirement. Waterproofing is achieved by employing specific, seamless systems and cannot be guaranteed solely by making joints waterproof.
Is it possible to bond ceramic tiles on an existing ceramic floor of a balcony?
You have to take various factors into consideration: the size of the balcony, the size and type of the existing tiles and of the new tiles to be bonded and the presence of joints in the old flooring. As far as Mapei is concerned, our guidelines recommend that, when installing a new floor over an old external floor, after preparing the surface as specified, you need to place a deformable waterproofing system such as MAPELASTIC between them. By doing this, MAPELASTIC guarantees that the layers underneath will remain waterproof and, thanks to its deformability, it will reduce the stresses induced by the presence of two floors, one on top of the other.