Tiling on gypsum plaster

Solution datasheet

Common issues and queries you can face

Gypsum plaster substrates

The gypsum plaster should be firmly adhered to its substrate and sufficiently strong to support the tiles.

Gypsum plaster is relatively a weak material in comparison to wood, block work, concrete or other cementitious material. The maximum weight of acceptable tiling on a dry and well-adhered gypsum plaster is of 20 kg/m².

Plasterwork should be completed at least 4 weeks prior to any tiling job. Even if the surface appears to be dry in less than 4 weeks, the layers underneath may not be properly cured or fully dried.

Gypsum plaster and water

Gypsum plaster is water sensitive and is therefore not an ideal substrate in wet areas such as bathrooms, showers, kitchens or wet rooms.

Gypsum plaster finish

The finished surface of gypsum plaster can be inconsistent and varies depending on the conditions and the workmanship.

The surface can be very dusty or, if over troweled, it can be very dense and shiny.

Cement based adhesive and gypsum plaster

When gypsum plaster comes into contact with cement, it forms a weak layer of ettringite that can prevent the adhesive from properly adhering to the gypsum plaster. Careful preparation is required to prevent this from happening.

Step by step solution

weber solution

Substrate preparation

The substrate must be sound, clean, strong enough to bare weight, free from dust, dirt, grease, oil or any contaminating materials that can cause adhesion failure.

For waterproofing over gypsum, apply 2 coats of acrylic waterproofing membrane

weberdry gum with the use of weber band embedded in the 1st coat (in all corners and sensitive points).
Tile adhesive

Apply webercol paste, a dispersing tile adhesive, uniformly on the substrate and use the notched spatula to achieve the required thickness.

Apply the tiles and press them strongly on the substrate in order to spread the product evenly on the walls. webercol paste can be used over gypsum substrate without any primer.
Tile grouting

It is recommended to have a minimum joint width of 2 mm around the tiles. Grouting should be done at least 24 hours after fixing tiles, using weberepox easy, weberjoint perfect or weberjoint deco.

Apply with a rubber trowel in a diagonal direction to completely fill the joint. Remove excess material from the surface with a damp sponge. When the grout is dry, clean it with a dry cloth.

Important note

Gypsum plaster loses most of its cohesive strength when wet, so it needs to be protected in areas wet areas. Therefore, a protecting layer such as weberdry gum is required when applying in wet areas.