Pencil tiles, also known as listellos, are small, thin decorative tiles that are frequently used to edge tile installations, create borders or to outline a break in the tile design. They can be one-quarter or one-half inch in width and may come in lengths of 6 , 8 or 12 inches in length. Pencil tiles come in nearly all materials and are frequently installed after the field tile has been set in place with an opening left for the pencil.
Lay out the tiles in the order they will be installed on a flat surface with the pencil tile in place. Cut the pencil tiles on a wet saw to fit in with the rest of the installation, and pay attention to how much space is needed between the field tiles for the pencil.
Install the field tiles, leaving a space for the pencil tiles. Hold a pencil tile up to the installation frequently to ensure that there is enough space left for it and that the tile rows are even.
Apply a small amount of thinset mortar to the backs of the pencil tiles and push them into place in the space left behind in the field tiles. Allow the thinset to dry for 24 to 48 hours.
Grout the pencil tiles with the rest of the installation. Use a grout float to push the grout into the spaces around the pencil tiles by dragging the float at a 45-degree angle to the field tiles as it approaches the area around the pencil. Drag the float over the curve of the pencil to get the spaces between the pencils and up from the field tiles below the pencil to get the areas beneath them.
Wipe the surface of the pencil tiles with a grout sponge to remove any excess grout. Dampen the sponge slightly and rinse it frequently to ensure no grout is left behind.