To choose the size of the hatch under the tiles, make your own calculation:

1. Decide on the location and approximate size of the revision opening;
2. Measure the height and width of the tiles;
3. Calculate how many tiles vertically and horizontally you need to place to completely cover the opening;
4. Multiply the number of tiles arranged horizontally by the width of the tiles – this is the width of the hatchway;
5. Multiply the number of tiles arranged vertically by the tile height – this is the height of the hatchway.