Now use shears to cut where you marked and you ll have the perfect size piece for that opening.
Tile over basement wall.
Be sure you double check the fit with the paper backing still on.
Place a second uncut tile over top of the open space overlapping the tile you just placed below make sure it is flush with the wall then use the bottom to mark the tile beneath.
You can get this from construction or hardware stores.
Ventilate and dehumidify the area before during and after the installation because basement walls are usually susceptible to moisture.
Subtract 1 4 inch from that measurement to get the necessary tile size.
For tiling over tiles in bathroom walls you ll need to set up sheets of waterproof membrane in between the concrete wall and tiles.