The need for light, privacy, and decorative accents are the driving forces behind the use of glass block in bathrooms. Designer Peter Lawton says glass walls allow light to pass through so they give the perception of a larger space. “In a 37-inch-deep shower with a solid wall, you feel like you are in a cubby,” he says. Replacing the solid wall with glass block makes the space feel larger and brighter.

Pittsburgh Corning

Lawton says glass block is a chameleon because it can be used in both traditional and contemporary designs. Though he mostly uses it in modern layouts, some of the conservative clients of Worcester, Mass.–based designPLUS who don't like stainless steel or other modern materials are more open to glass block as an accent. “We're just finishing a very traditional bathroom with earth tone colors and a large radius glass block shower,” he says. The material is also ideal for windows in close-set urban houses where privacy is an issue.

Even in San Francisco, many of the clients of designer Peggy Deras, Kitchen Artworks, don't often choose glass block. “It takes a special client and special home to be able to take it,” she says. The first time Deras used glass block was in a bathroom for an adventurous client. Her preference is to repeat a design element, so she used it in several places. “I used it in the shower, then in a window behind the shower, then brought it across the room and used it in the toe kick,” she says.

Deras also likes combining different glass patterns. For a recent San Francisco apartment remodel, she chose glass block for the shower divider and the low window in the shower. The lower section of both the window and divider features obscure blocks and the upper sections boast clear block.

Designer's Block Before using glass block in a project, designers need to know the limitations of the material.

Bob DeGusipe, marketing manager of Pittsburgh Corning, says the company does not recommend cutting glass block. Instead, he suggests finding a way to use the variety of pieces and shapes his company offers, which include curves, 45-and 90-degree corners, and shapes to finish the edges. The product is also not designed to be load-bearing. For islands or under countertops, engineers at Pittsburgh Corning advise installing a structural support to hold the weight of the counter and then wrapping it with glass block.

Tabor Construction

Lawton asks his installers to set the block on a solid base of tile and to tile the surface where the glass block meets the wall. “This is so if a joint fails or water gets behind the seam, it won't ruin anything,” he says.

He adds that many installers think they can put up an 8-foot-tall glass block wall in one day. “They don't realize you can only let it set three or four blocks high,” he says. Due to the weight of the glass, the first courses have to dry before the installer can set the higher blocks.

When Deras specified a glass block window in a shower, she wanted the glass tile to be flush with the tiled wall. (At that time, pre-made window units were not available, see “Glass Block Windows”.) Her contractor created an aluminum frame to set the blocks in the opening.