To install ceramic tiles on a subfloor, follow these steps:
1. Substrate preparation: The subgrade must be clean, flat and dry before starting. If uneven, use a self-leveling chemical to level it. Make sure the subgrade is free of debris or loose materials.

2. Measure the area: Measure the area where you will be installing the tiles to determine the amount of tiles and other materials needed.

3. Plan your layout: Plan your tile layout, including any necessary cuts. Start by defining the center of the room and drawing a grid. This will help you ensure that the tiles are straight and even.

4. Plastering: Use a notched trowel to apply a thin layer of mortar to the floor. Make sure the mortar is even and only covers a small area at a time.

5. Tiling: Start tiling in one corner of the room, gradually extending across the subfloor. Press each tile firmly into the mortar, making sure it is flush with the surrounding tiles.

6. Cut the tiles: When you reach the edge of the room, you need to cut the tiles to fit. Use a tile cutter or wet saw to make the necessary cuts.

7. Let the grout dry: Let the grout dry for at least 24 hours before walking on the tiles.

8. Plastering: After the mortar has dried, use a trowel to apply mortar to the joints between the tiles. Make sure the mortar is applied evenly and covers all joints.

9. Cleaning the tiles: After the mortar has dried for about 10 minutes, use a damp sponge to clean the tile surface.

10. Seal the grout: Once the grout is completely dry, apply a coat of sealant to the grout to protect it from moisture and stains.


By following these steps, you can install ceramic tiles over a subfloor and create a beautiful and durable floor surface.