1. Aim
To determine the adjustment time of tile adhesive, i.e. the maximum time during which a tile can be repositioned after fixing without affecting bonding.
2. Apparatus / Materials Required
- Tile adhesive sample
- Clean water
- Mixing tray / mixer
- Notched trowel (6–10 mm)
- Cementitious substrate (tile base)
- Ceramic tile pieces (50 mm × 50 mm)
- Timer / stopwatch
- Marker / chalk
3. Method / Procedure
The tile adhesive is prepared by mixing it with clean water as per the manufacturer’s recommended proportion until a uniform paste is achieved. The mixture is allowed to rest for 5–10 minutes (slake time) and then remixed. The adhesive is applied evenly on a clean and dry substrate using a notched trowel at a 45° angle to form uniform ribs. Immediately after application, tile pieces of 50 mm × 50 mm size are fixed on the adhesive surface and a timer is started. At specified time intervals (0 to 45 minutes), each tile piece is rotated to 90° and then brought back to its original position without lifting it from the adhesive. During this process, only normal hand pressure is applied. The ease of rotation is observed carefully at each interval. The adjustment time is determined as the maximum time at which the tile can be repositioned easily without applying force.
