Step 1: Determine Number of Blocks

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.

Step 2: Organize Panel Anchors

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 run. It’s important that they are ready beforehand so as to not stop progress once the mortar is prepared.

Step 3: Prepare Mortar

Follow the manufacturer’s instructions when mixing mortar. Typically, cool water should be added slowly until a consistency of cake frosting is achieved. The consistency should be spreadable, but not dry to the point of separating or crumbling. Mix only what can be used in about an hour.

Step 4: Install First Course

Use the trowel to apply a full mortar bed to the sill. Enough mortar should be used so that a 1/4" joint will remain when the block are set in place. Position a spacer in the first corner and then set the first block into the mortar. Make sure the block is straight and level. Remove excess mortar.

Step 5: Complete First Course

Butter the vertical side of the next glass block with a layer of mortar. Place a spacer against the base of the first block before setting the second. Set the second block into the mortar, make sure it is straight and level, and remove excess mortar. Complete in this process until first course is complete.

Step 6: Set Second Course

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

Step 7: Install Panel Anchors

After the second course is completed, install a panel anchor at each end. Attach the short end of the anchor to the jamb using drywall screws. The long end should lie flat on top of the second course of blocks.

Step 8: Complete Wall

Lay the third course of glass block in the same fashion as the others, first laying mortar atop the panel anchors and then setting blocks. Install panel anchors every second course. After the final course has been set, remove excess mortar from block faces using a damp sponge. Be sure to rinse frequently and avoid abrasive cleaning products. After the mortar has set up for an hour, smooth all joints with a striking tool.

Tip: For bathroom applications, mortar joints should be coated with a clear sealer for mold and mildew protection.