How to Install a Glass Block Shower Surround - dummies

How to Install a Glass Block Shower Surround

By Gene Hamilton, Katie Hamilton

If you liked working with building blocks or LEGO blocks as a kid, you’ll enjoy building a glass block shower because all the pieces fit together to create a dramatic new shower room. To install a glass block shower kit, you need the following:

  • Bucket

  • Carpenter’s level and square

  • Drill and bits

  • Glass block shower enclosure kit

  • Margin trowel

  • Mineral spirits

  • Mortar or plaster mix

  • Rubber gloves

  • Safety glasses and respirator (for mixing mortar)

  • Silicone sealant

  • Slotted screwdriver

  • Tape measure

  • Tin snips

Prepare the subfloor

The shower receptor base requires a bed of mortar or plaster mix placed under it for proper support, so that’s where you begin:

  1. Apply mortar on the subfloor 2 inches thick in a 12-inch-x-12-inch grid pattern the full length and width of the shower base.

    Be sure that the grid extends under the vertical support board of the curb.

  2. Use a carpenter’s square to level the shower base around the perimeter.

    Avoid standing in or loading the base until the mortar has set.

Install the shower base

  1. Sand a 4-inch-wide area along the top of the acrylic shower pan’s curb with 80-grit abrasive paper.

  2. Drill two 3/16-inch-diameter pilot holes in the curb for attaching each of the panel anchors.

  3. Mix three parts of the primer with one part water and brush the diluted primer onto the area you just sanded.

  4. After the primer becomes tacky (3 to 5 minutes), predrill the curb that the block rests on and fasten the metal panel anchors to the shower pan with 2-inch screws and washers.

    Note that the first anchor is 10 inches from the wall.

Build the glass enclosure

  1. While the primer is still sticky, apply a 1/4-inch bed of glass block mortar to the curb with a small trowel.

  2. Place the 3/8-inch-thick foam expansion strip between the first block and the shower wall.

  3. Place a 4-x-8-inch block against the shower wall and use the trowel handle to tap it down into the mortar. Next to the block against the wall, begin laying 6-x-8-inch blocks, placing the panel anchors between the vertical mortar joints.


    The combination of 4-x-8 and 6-x-8 blocks gives the proper spacing so the end of the wall aligns with the end of the curb molded in the shower pan. Repeat every other row of block, using reinforcing mesh.

  4. Place spacers between the blocks to ensure consistent, evenly spaced mortar joints.


  5. Install reinforcing in the last vertical joint of the straight section just before starting the curved section.

  6. Form the curved section of the shower by laying four consecutive curved glass blocks, using spacers. Put an end block that has a rounded corner (to give the wall a finished look) at the ends of the walls.

  7. Install a second row of blocks.

    As you install the blocks on a mortar bed, use the level to ensure the wall is straight and level.

  8. Tie the glass block to the shower wall with metal panel anchors placed on every other row of blocks.

    Apply mortar to the block and then place the anchors on the glass block and secure the anchor to the wall stud with several screws. If there is no wall stud behind the anchor, use wall anchors.

  9. Install metal horizontal reinforcing strips on tops of the blocks to hold them together.

    Cut the inner edge of the metal reinforcing strips so they can be bent to follow the curve of the wall.

  10. After you finish the fifth or sixth row of blocks of the curved wall, begin the short straight wall.

  11. After laying the final course, and before the mortar stiffens up, check the walls one last time to make sure they’re vertical.

  12. After the mortar has fully cured, fill the joint between the wall and the glass block with clear silicone sealant.

    Put on a rubber gloves and wipe the silicone with your finger dipped in mineral spirits to smooth it for a finished, professional look.