How to Lay Glass Block Tiles

A glass block wall provides strength and energy efficiency while allowing in light.

Installing a glass block wall is not too difficult as long as care is taken to plan and begin the installation correctly. Glass blocks are easier than other types of block or brick walls because of the special plastic spacers that are sold to aid in the installation. They support the blocks so you don’t have to be a master mason to get the installation right. The only problem with glass block walls is, unlike other types of masonry, they cannot be cut, so care must be taken to plan the size opening that will be covered by the glass blocks.

Things You'll Need

• Brick mortar
• Glass block spacers
• Glass blocks
• Level
• Trowel
• Sponge

Instructions

1. Lay out a row of glass blocks without using any mortar. This will give you a feel for how the spacers work. There are “L” shaped spacers for the bottom corners, “T” shaped spacers for the bottom and ends of each row and “X" shaped spacers for the rest of the wall. These spacers will remain in place so make sure they are centered and straight and that the mortar covers them.

2. Mix the mortar according to manufacturer’s instructions and place a layer of it across the base of the area to be blocked. Make it approximately one inch thick, but precision is not needed. Try to create a smooth, even layer across the width of the wall.

3. Place a corner spacer in the bottom corner and rest your first block on it. Place a “T” spacer under the other side. Tap down on the block with the handle of the trowel to seat it firmly in the mortar and flat on the spacers. Use the point of the trowel to smooth out the mortar to make a nice joint. You will be smoothing this further in a moment.

4. Lay the rest of the bottom row in this fashion, one block at a time. Make sure each one is straight and level with the one next to it and is resting firmly on the spacers.

5. Use the level to make sure the top is completely level and the blocks are straight when the bottom row is finished. Wash the blocks with a damp sponge to remove excess mortar and smooth out the bottom joint.

6. Continue in this fashion one row at a time. Spread mortar in the joint of the row below and place spacers between each block. After completing each row, check the top for level and the sides for straight and plumb.

7. Wash excess mortar off as you go and make sure the mortar joints are straight and smooth. Make sure you don’t have any plastic spacers exposed in the mortar. When complete, wash the wall again to remove any mortar residue. Allow to set for 24 hours and then wash again with clean water.

Tips & Warnings

• Usually white mortar is used between glass blocks, but any color you like will work.

• Make absolutely sure that every row is level and the wall is plumb. The spacers take a lot of guesswork out, but it still takes some care to ensure a proper installation.

References

• BobVila:Installing a Glass Block Wall