How to Block a Walk-in Shower

Mark the position of your shower entrance along the edge of the shower pan, using masking tape. Place two long strips of masking tape along the shower pan, perpendicular to the edge, to mark the left and right side of the entrance.

Roughen the edge of your shower pan using fine-grain sandpaper. Gently scratch the surface of the pan with the sandpaper just enough to remove the shiny finish. This will help the mortar adhere to the shower pan. Do not sand the shower pan along the space you intend to use as your shower entrance.

Prepare a batch of glass-block mortar by following the manufacturer's instructions. Mix the mortar in a large plastic bucket, using a drill-powered mixer to stir the mortar to a smooth, even consistency.

Spread a 1/2-inch layer of mortar on top of the shower-pan edge along one side, beginning with the side where the shower pan touches the wall. Apply the mortar using a small trowel.

Set your first glass block upright in the mortar you just spread. Position the block about a half inch from the wall where it connects with the shower pan. Install additional glass blocks next to each other, leaving a half inch of space between the blocks, until you've blocked one side of the shower pan.

Lay a level between the tops of each pair of glass blocks as you install them, to check that they sit at the same height. Adjust the glass blocks, when necessary, by tapping them gently with a rubber mallet.

Use the trowel to spread a 1/2-inch layer of mortar along another side of the shower pan. Continue laying glass blocks and applying mortar to the edge of the shower pan until you've completed the first blocked row. Do not apply any mortar or lay any blocks in the space designated for the shower entrance.

Fill a mortar bag with mortar. Squeeze the mortar into the 1/2-inch gaps between the glass blocks -- and between the glass blocks and the wall on either side of the shower pan.

Apply a layer of 1/2-inch mortar on top of the first layer of glass blocks. Install a second row of glass blocks on top of the first, following the same procedure. Leave a half inch of space between the blocks and between the end blocks and the wall.

Repeat Steps 7 and 8, building up the walls of the walk-in shower until it reaches the desired height. For the final layer of blocks, use glass blocks with a finished edge to give your walk-in shower a finished look.

Brush away any excess mortar, using a stiff brush. Allow the mortar to set for a full 72 hours before using your new walk-in shower.