How to Install Glass Block Door Sidelights

Lead Image for How to Install Glass Block Door Sidelights
  • 8-16 hours
  • Beginner
  • 300-1,000
What You'll Need
Glass blocks
Bucket to mix mortar

Installing glass block door sidelights is no more difficult than laying tile and works on the same principle. Adding glass block sidelights has many advantages including allowing more light to enter the room will providing a great deal of privacy, a good layer of insulation against the cold and drafts, and protection from break-ins as they are almost unbreakable.

Preparing the Area

If you already have regular window sidelights, you will need to remove the glass and all surrounding wood all the way back to the frame. Be sure to scrape the frame free of paint, splinters, and nails to create as smooth an area as possible. Measure the length and height of the wall to determine the number of glass blocks needed for the job. Don’t forget to add 1/4" to 1/2" for mortar joints between each block and at the ends of each run. Test fit the blocks without any mortar to judge the fit.

Panel anchors should be cut into 12" lengths and bent into a right angle at the 3" mark. This produces an anchor with one long and one short arm. These anchors will be attached to the jambs after every second row of glass blocks. It’s important that they are ready so as to not stop progress once the mortar is prepared.

Follow the manufacturer’s instructions when mixing mortar. Water should be added slowly until the consistency of cake frosting is achieved. The consistency should be spreadable, but not dry or crumbling. Mix only what can be used in about an hour as it dries quickly.

Installing the Blocks

Lay enough mortar on the bottom of the frame so that when you set in the first row of glass blocks and they settle you will have at least 1/4 inch mortar line all the way across the span. Put a spacer between the frame on the side and the first block, then press in place. On the next block, put a spacer between it and the first block after laying mortar on the vertical surface between the two blocks. Continue all the way across on the first row. Check often to make sure this row remains level.

Second Row

Place spacers between the tops of all bricks in the first row. Apply and smooth a mortar bed across the top of the first row of blocks. Be careful to keep the spacers as free of mortar as possible. This will ensure that the next row of blocks fits correctly. Lay the second row of blocks in the same fashion as the first.

After you have completed the second row of blocks, install a panel anchor with the long end embedded in the wet mortar and the short end screwed into the wood frame. This will hold the blocks straight and anchor them.

Completing the Project

Continue on with the rest of the blocks in this manner until all are installed. Wipe all the glass clean of mortar as it will be almost impossible to clean once the mortar has set. When the mortar has partially set, remove the spacers. After allowing the mortar to set until dry, you may want to coat it with a water-resistant sealer. Caulk with clear caulking between the glass blocks and the frame for added sealing.