To install glass blocks, make a frame for the blocks out of 1-by-6-inch lumber, mix glass-block mortar, spread the mortar on the bottom and sides of blocks, and install a layer of blocks from one corner of the frame to the other. Add more mortar, a metal retaining strip and additional layers of blocks.Continue Reading
Lay the blocks on a table with spacers between them to determine the size of the frame. Cut 1-by-6-inch lumber for the frame, and fasten the pieces of lumber together with screws. Install the frame in the aperture where you plan to install the blocks.
Mix glass-block mortar according to the manufacturer's directions. Spread the mortar on the bottom and sides of the first block. Lay the block in the bottom-left corner of the frame, using spacers to get a proper fit.
Spread mortar on the bottom and sides of additional blocks. Add the blocks to the frame, positioning them next to each other until the row is complete.
Attach a metal retaining strip to the top of the row, and screw the strip into the frame.
Spread mortar on top of the first row of blocks, and cover the entire retaining strip.
Continue adding rows of blocks until the frame is full, securing retaining strips between each row.
Let the mortar set for an hour, and then wipe it off the blocks with a damp sponge. Let the mortar cure for 24 hours before using the area.