The main cementing material of gypsum-based self-leveling mortar is gypsum, and it has the performance of automatic leveling. The ground leveled by it is accurate in size and extremely level. Gypsum itself has the characteristics of micro-expansion. Using it as the basic material for self-leveling can make the leveled ground stable. The risk of cracking is greatly reduced.
At the same time, gypsum-based self-leveling mortar is pumped for construction, which is very efficient. After the leveling is completed, the strength can reach more than 90% of the design strength in one day. The decorative surface layer can be constructed in 1 to 2 days. A variety of floor materials can be laid on self-leveling mortar, including wooden floors, PVC plastic floors, floor paints, various tiles, marble, etc. However, it is also reminded here that tile laying cannot be carried out directly.
Gypsum-based self-leveling mortar can harden in a short time, and people can walk on it 4-6 hours after the mortar is poured. However, a thin layer of mortar will form on the surface during the hardening process. This layer is too weak to lay tiles, and it also slows down the drying time of the mortar.
When cement-based adhesives are applied directly to the floor, the cement in the tile adhesive reacts with the gypsum in the mortar self-leveling. A mineral called calcium sulfonite is formed at the interface. The related structural changes are sufficient to completely separate the cementitious adhesive from the flattened base.

Therefore, before laying tiles on gypsum-based self-leveling mortar, necessary preparation measures should be taken.

To seal the porous surface of the gypsum base to prevent moisture from being absorbed from the tile adhesive. At the same time, it can avoid the adverse reactions that often occur between cement-based mortar and gypsum substrates. Specifically, primer spraying can be performed between the gypsum self-leveling and the tile to seal and isolate. It can be a hydrophobic emulsion or a reactive resin to avoid problems such as poor bonding caused by direct paving.
Gypsum-based self-leveling mortar is used for ground leveling layers and has advantages that other materials cannot match. With the promotion of finished residential products, the application of building floor heating backfilling and ground lifting is also increasing. Lifting and leveling construction can be completed at one time with self-leveling mortar. And using it for floor heating backfill can also make floor heating have better insulation and energy-saving effects during application.
But as we said before, a variety of floor materials can be laid on self-leveling mortar. But when laying tiles, primer spraying and sealing isolation measures should be taken to achieve a good floor laying effect.
HPMC for self-leveling mortar