Dear James: I want to build a curved glass block wall for a shower stall and a straight one in my kitchen. How do lay a glass block wall so that it will not leak when showering? —Darlene G.
Dear Andrea: Glass block walls can give a house a very open look and make smaller rooms appear to be much larger than they are. They can also provide more even lighting though the wall while still providing privacy design on the type of blocks used. Some patterns just distort the view while others totally obscure it.
A straight glass block wall is easier to build than a curved one, so start with that project first. The idea of using a curved wall for a shower stall is wise because you can get more usable shower space than with a rectangular stall. Consider installing LED light strips in the joints between the blocks for attractive lighting.
Up until about a decade ago, unless you were experienced in laying curved glass block walls, I guarantee you would have been disappointed with your first job. It takes quite a bit of skill to make glass walls level and even. This was particularly true for shower stalls where one end is open and the top does not meet the ceiling. With only one support side, it could feel unstable.
The do-it-yourself kits available today make it easy for someone with very little glass block experience to lay a very even, properly spaced wall. These kits include glass block spacers that position the glass blocks relative to one another. This results in a strong level wall with very consistent mortar joints.
When selecting the glass blocks at your home center store, stack several together to determine if they will provide adequate privacy. Once you have selected the type and size of glass blocks you desire, purchase the spacers to match the blocks. Even though glass blocks are hollow, they can get quite heavy, so have someone help you carry them.
The first step is to design the curb from concrete landscaping bricks to support the glass blocks. Don’t start placing the glass block wall directly on the floor or you will surely have leaks. Temporarily place the first row of glass blocks on the floor to determine the number and shape of concrete bricks you need.
Set the concrete bricks in a layer of thinset. Next, lay a film water barrier on the floor and bricks and flow a layer of mortar across the shower stall floor over to the bricks. For a more decorative look, cap the top and sides of the concrete bricks with a thin marble veneer, or just start the glass block wall over the bare bricks.
Laying the first course of glass blocks properly is most important because it is the foundation for the rest of the wall. Make sure to use special mortar formulated for glass blocks and place the glass blocks in a heavy layer of it. Use a good level to make sure they level in both directions.
Place plastic glass block spacers on top of the first course, apply mortar, and lay the second course. Repeat this up the wall. Install metal reinforcement in the mortar joints and to tie the glass blocks to the bathroom wall. As the mortar sets up, break off the ends of spacers and finish the joints with grout.