Constructionscope.net shows a new technique to create a glass block wall:

Glass block walls first started appearing in homes built during the 1950’s and 1960’s, and they are still popular today for their ability to transmit soft, diffused light while defining separate living areas with a sense of openness. In addition to the traditional squares, glass blocks are now available in a variety of shapes, sizes, and even colors. Wall sections of glass blocks can be built to varying heights, and they can also be used to create unique-looking shelves. One consideration for this project is that glass blocks do need a solid foundation. If installing them over a wood floor, the floor will probably need to be reinforced before beginning. Different glass block manufacturers can also have different installation methods for different types of glass blocks, so it is always a good idea to consult the manufacturer’s included specifications.



Tools and Materials Needed:

Panel anchors
8 inch diameter glass blocks
Wall trim
16 gauge wire
Board
Reinforcement wire
¼ inch T-spacers
Baseboard panel
Glass block mortar
Foam expansion strips
Drywall screws
16d size nails
2x6 lumber pieces
Asphalt emulsion
Sponge
Nylon-bristle brush
Jointing tool
Circular saw
Jigsaw
Level
Pliers
Trowel
Mixing bucket
Cordless drill
Chalk line
Paintbrush

The glass block wall described here is built with a support sill made from two 2x6 wood pieces that are cut to the exact width of the blocks to provide a stable base. This block wall is also secured to an anchor stud within an adjoining wall, and expansion strips allow for movement without damage to either structure.

Step 1 – Dry Lay the First Row

Use one 3/8 inch wall spacer between the wall and the adjoining glass block, and use ¼ inch spacer between the rest of the glass blocks to set gaps for the mortar joints. Make a mark for the glass wall position along the floor, and snap a chalk line along the marks in order to create an outline for the support sills.

Step 2 – Measure Sill Thickness

Use the size of the wall baseboard and the thickness of the top floor covering to determine how thick your glass block wall’s sill should be. Cut your 2x6 inch lumber to the width of the glass blocks, and then use your jigsaw to trim the ends of the sill pieces to fit with the shape of the end block.

Step 3 – Fasten Sill and Mark Plumb Lines

Using the 16d nails, attach the sill to the subfloor and framing underneath. Brush a coat of asphalt emulsion to the sill with your paintbrush. Start at the sides of the sill, and then mark plumb lines on the adjoining wall. Also mark the finished heights of each row of glass blocks. At the top of every other row, attach an anchor stud with the drywall screws. Trim each of your Foam expansion strips to fit, and secure them to the wall in between each of the anchor studs.

Step 4 – Set Glass Blocks with Mortar

Mix enough mortar to use within 30 minutes, and spread a 3/8 inch thick layer on the wood sill, which should be enough for up to 4 glass blocks. Set each of these blocks with the ¼ inch T-spacers in between, and make sure not to place mortar between the blocks and wall expansion strips. Spread enough mortar on the sides of each glass block to fill the space between it and the next subsequent block.

Step 5 – Level the Glass Block Courses

Continue laying each row of glass blocks as described in step 4. Check each row with your level as you go, and use your flat board and a rubber mallet to gently tap any uneven glass blocks into place. Once all blocks are even and level, fill in any remaining joints with mortar, and then spread a coat of mortar at the top of the first completed row in order to lay the second row.

Step 6 – Install Reinforcement Wire and Fill in Gaps

In the same joints as the anchors, attach 16-gauge reinforcement wire so that it overlaps with the anchors by about 6 inches. At each of the block corners, bend the outside rail of the wire to follow the shape of the glass block corner. Once the mortar in between glass blocks has dried for about 30 minutes, remove the T-spacers and pack mortar in any remaining spaces. Smooth over all joints with the jointing tool, and then remove any extra mortar from the glass blocks with a damp sponge.

Step 7 – Apply Sealant

Allow 2 weeks for the glass block mortar to completely cure, and then apply a clear sealant with your caulk gun in between all seams between blocks and the adjoining wall. Let this completely dry, and then reinstall any surrounding flooring as needed.