Installing a Glass Block Wall

two 8-foot 1x6 #2 pine boards
four 12-foot Colonial casing
25 8x8-inch glass blocks
10 4x8-inch glass blocks
painters caulk
one gallon white enamel latex trim paint
two tubes clear latex adhesive caulk

Tools:

caulking gun
framing square
level
mortar trowel
morter smoothing tool
power miter box
speed square

1. Measure the opening for the glass wall. Glass blocks are typically 8x8-inches, so once you have the measurements you can calculate the number of blocks needed. Glass blocks can’t be cut, so work with full 8-inch increments.

2. Arrange the blocks on a table, using the spacers in the kit, to get the actual size of the installation. Make a frame out of 1x6s to enclose this group of blocks.

3. Cut the 1x6s to the length of the sides, and then to the length of the bottom, and add 1-1/2 inches. Assemble the frame using screws or nails.

4. Install the frame. Make sure to center the frame into the opening, blocking and shimming where necessary. Make sure the frame is square and level before attaching it to the opening (figure A).

5. Mix the glass block mortar according to the directions on the package. Begin laying the block in a corner, and work your way across. Spread the mortar (aka "butter") on the bottom and edge of the glass block, and then squeeze it into the corner using the spacers (figure B). Keep working left-to-right until the first course is finished.

6 Install the retaining strips. Screw the metal retaining strips to the side frame, and bend into place to fit between each row of blocks. They are there to strengthen the wall and attach it to the structure.

7. Butter the entire first row of glass blocks, making sure the retaining strips are centered in the bed of mortar, and then squish a reinforcing strip into the mortar (figure C). Hide the reinforcing strip so it is not visible.

8. Lay the next course of glass block, and continue this process to the top (figure D).

9. Once the mortar has set up a bit, use a sponge and water to gently clean the block and shape the mortar with the mortar shaping tool. The dust that dries on the block can be removed with a dry cloth (figure E).

10. After the mortar has hardened, run a clean bead of caulk around the perimeter of the block.

11. Finish by installing casing molding to cover the gap between the 1x6 frame and the original wall (figure F). Fill and paint the molding and frame.