Glass block is an alternative way to let light into a room like a bathroom without needing window treatments. Observers cannot see through the glass block into the room but the area permits natural light to enter. Installing a panel of glass blocks is the perfect way to naturally brighten a shower stall.
You will need:
• Glass blocks
• Glass block panel anchors
• Glass block mortar
• Glass block spacers
• 1×2-inch board
• Water-resistant drywall
• Drywall screws
• Drywall nails
• Water-based asphalt emulsion
• Foam expansion strips
• Panel-reinforcing wire stabilizer
• Phillips driver bit
• Drill press
• Notched trowel
• Scouring pads
• Striking tool
• Plumb bob
• Caulk gun
• Safety glasses
Step 1: Nail a 1×2-inch wood strip along the center of the rough opening. This will support the weight of the glass blocks. To finish the opening, attach water-resistant drywall strips on both sides of the board.
Step 2: To protect the wood from moisture damage, apply one coat of the asphalt emulsion to the wood on the sill. Do not apply this too close to the edge of the sill. The glass blocks create a lip around the opening perimeter.
Step 3: Bend each panel anchor to form a 90-degree angle at 3 inches from one end. Attach anchors to the jamb at a height that equals three blocks. Depending on the amount of mortar that will be used, adding ½-inch to the measurement will compensate for it. For each third row of blocks, attach another anchor. The anchors help the blocks secure to the jamb.
Step 4: Install the foam expansion strips all around the opening. When the temperature changes, these strips enable the glass blocks to contract and expand. They also mask the emulsion located on the sill.
Step 5: Mix the mortar and press a handful of it against the side of one glass block. If it remains in place, it is ready to use.
Step 6: Use plastic spacers to dry-fit one row of glass blocks. Cut edge and corner spacers so the sides located against the wall are flat.
Step 7: Once you have fit the blocks together in the desired way, begin laying blocks using mortar. Lay a line of the mortar on the sill. Use enough so the mortar squeezes out when the blocks are set in place. Do not apply mortar to jambs. Set the spacers into place and then put the first block in place.
Step 8: Take the next block and apply mortar on the side that will be closest to an adjacent block. Repeat this process until the first row has been completed. Check this row for plumb and level. Continue laying each row, following the steps above, until all blocks are used.
Step 9: Use a damp sponge to wipe off excess mortar.