A glass block window does not open, limiting airflow into and out of your home. Glass block windows have special vents available for them. These vents differ in size but are designed to fit into one or more blocks of glass. You now have to replace some of the blocks to install the vent into an existing window.
Glass blocks can be used to create basement windows. Removing the substance that was used to hold the glass block in place, which can be either mortar or industrial grade silicone caulk, is required to remove it from the wall. After removing the glass block, replace it with special glass blocks built to handle dryer vents; some glass blocks already have the dryer vent installed.
Steps to follow in venting an existing glass block window
Step 1: Measure the vent’s size to determine how many glass blocks you’ll need to remove to install it.
Step 2: Using a razor or knife, cut through the mortar around the glass blocks. If this doesn’t work, drill through the mortar with a masonry bit. To remove the blocks, break apart as much of the mortar that surrounds them as possible.
Step 3: Take out the blocks and place them aside. Any dust and debris from the mortar removal should be vacuumed up.
Step 4: Using a trowel, apply a quarter-inch line of mortar around the vent and slide it into place in between blocks. Allow the window to dry for 24 hours after wiping away any excess mortar with a wet cloth.
Step 5: To keep the vent airtight, apply a line of caulk around it.