Ten or 15 years ago, interior glass block was all the rage. I installed it regularly in bathrooms and kitchens and often as a design element in entries and living rooms. Glass block both lets in light and obscures visibility—all in the texture of a block wall. While glass-block installations here in the Northeast have become rarer, they are still common on the West Coast and in Florida.

I recently installed a freestanding glass-block partition as part of a walk-in shower. The glass-block wall helps keep an adjacent vanity dry while offering a modicum of privacy to the person in the shower. The installation methods I use haven’t changed much since my first glass-block projects. As with most projects like this one, proper preparation is the key to success.

The glass-block wall in this shower is nonstructural, meaning that it doesn't support anything other than its own weight. The block wall sits on the tile floor, attaches along one wall, and stops a couple of feet shy of the ceiling. We opted to finish the exposed edges of the block with limestone tile.

The most important thing to remember when installing glass block is to keep the courses plumb, level (both across the block and across the courses), and in plane. Also, always use the proper mortar and reinforcement, and don’t try to install too much in one stint.

Layout and Prep for the Glass Block

This glass block wall is to be four blocks wide and ten blocks tall. The author begins by laying out four glass blocks on the floor and then tracing around them to mark the position of the wall.

He scarifies the tile on the floor with an abrasive wheel on an electric grinder, which roughs up the surface of the tile to help the thinset adhere.

After extending the layout up the wall with a long level and scarifying the wall tile inside his layout, he cuts out and removes small sections of tile to expose the wall framing for attaching reinforcement as he builds the block wall.

He coats the floor tile and wall tile with a layer of modified thinset that will help the glass block mortar adhere.

One final quick check of the floor for level and he is ready to begin installation.

 Install the First Blocks