A glass block window is an excellent way of letting in light but not allowing visibility in spaces where privacy is paramount, such as a bathroom. Installing a glass block window is easy if you have any previous experience with laying brick or other masonry. Follow these easy steps to install a glass block window in a previous window opening.
Begin the installation by deciding how large you want your glass block window. You should account for mortar joints that are Ã?Â¼” in addition to the size of the glass blocks you wish to use. Keep in mind that the window opening will have to be reinforced due to the extra weight; so be sure to contact your local building department for any code requirements. Typically, you should be able to double the rough sill and add additional cripple studs to meet the requirements.
Next, install the perimeter channel. Begin by installing the bottom and side pieces. You want to make sure that the channel is flush with the wall sheathing on the outside of the wall. Cut to fit the size of your window opening, being sure to miter the edges at a 45 degree angle. Install the perimeter channel to the window opening with screws spaced 12 inches apart. Plan on painting after the installation to conceal the screws.
For the top of the perimeter channel, cut the channel in half lengthwise. Install the piece of the perimeter channel that belongs on the exterior of the window with screws, but withhold the interior perimeter channel piece for later installation.
Now you can begin installing the glass block window. Begin by placing two glass blocks, one in each corner against the jamb in the window sill. Then take a Ã?Â¼” plastic spacer and place it against one of the blocks. Take a third block, and buttering it with mortar, place it tightly against the first block, Make sure that the joint space made by the plastic spacer is completely filled with mortar.
Repeat the same procedure, except working on the other corner block. Add one glass block to the row on each side until the glass blocks meet in the middle. Be sure to butter both sides of the final glass block in that course. When the course has been laid, use a rubber mallet to set each block by tapping on the top of the block.
Next use a T spacer to create a bed of mortar for the next course of glass block to be placed on. Use your spacer as a guide to butter the top of the previous course with enough mortar to install the next course.
Remove spacers as the mortar sets, filling in the void they left behind with more mortar. Also finish the edges of the mortar with a jointing tool as you install the rest of the window. Then continue laying the glass block in the window until it is all installed.
Once all of the glass block is installed in the window, you can install the last of the perimeter channel. Using the piece you discarded in the previous step, apply construction adhesive and ease it into the opening between the top of the glass and the header.
Finally you should carefully clean all of the glass block of any mortar residue. Using caulk, seal all of the seams between the glass block and the window perimeter and any framing members. Wait two weeks to allow the mortar to cure, and then seal it with a high-grade sealant to keep the joints looking new.
Installing a glass block window can be easy, but should only be attempted by someone with some home improvement experience. If you are unsure if you can complete this project, call a professional. Most contractors or repair people should be able to finish the majority of a project like this in a few hours.