Lay the first glass block in place.
Add a small amount of mortar to the side of the block using a trowel.
Place the next block into place. Hold a ceramic tile turned on its edge between the two blocks to ensure you place each block the same distance apart.
Remove the tile and place your next glass block. Continue to measure the distance using the tile until the first row is complete.
Place a laser level on top of the first row to ensure that it is level.
Run a line of mortar on top of the first row of glass blocks and begin placing your second row. Space the row using the ceramic tile.
Continue using the level and the tile until the entire wall is complete. You may use more than one tile to prevent having to remove the tile and moving it to the next one.