IS 15477:2019 is the Indian Standard for tile adhesives. It sorts adhesives into types by how strongly they bond and the conditions they are tested in. The higher the type, the higher the minimum strength.
The types at a glance
| Type | Tensile min (dry) | Shear min (dry) | Tilexo grade | Our result |
|---|---|---|---|---|
| Type 1 | 0.5 N/mm² | 1.0 N/mm² | ST1 Silver | 0.63 / 1.10 |
| Type 2 | 1.0 N/mm² | 1.25 N/mm² | ST2 Gold | 1.21 / 1.32 |
| Type 3 | 1.5 N/mm² | 1.5 N/mm² | ST3 Diamond | 1.71 / 1.87 |
| Type 4 | 1.5 N/mm² | 1.5 N/mm² | ST4 Platinum | 1.76 / 1.97 |
Two more letters to look for
- T (slip resistant). On a wall, the tile slides no more than 0.5 mm while the adhesive sets. Needed for wall tiling.
- S1 / S2 (deformability). How far the adhesive can flex with the surface. S2 is the most flexible class. ST4 Platinum is S2.
Quick rule of thumb
- Ceramic floor tiles: Type 1 (ST1 Silver).
- Vitrified tiles, walls, kitchens and bathrooms: Type 2 (ST2 Gold).
- Large-format tiles and busy floors: Type 3 (ST3 Diamond).
- Very large slabs and premium installs: Type 4 (ST4 Platinum).
Still unsure? The product finder asks three questions and picks the grade.