You can install your own glass block window in as little as one day and add beauty and privacy to your home.
When looking for an alternative to traditional glass windows or partitions, glass blocks can be the next best thing to use. Glass block allows light into a room and adds a layer of privacy that plain windows cannot offer. The installation can be quite simple if you use one of the kits that are available. These kits include the tracks that you attach and lay the blocks in.
To begin you will need to remove any existing window and window hardware from the window framing. Repair or replace any damaged sections of framing and fill any holes from screws or nails. If you are installing on a wood frame you will need to brush on a protective sealant before you begin. Be sure the opening is square and all sides are level by using a carpenter's level. If it is not level you will need to make it level and square as well.
Before you begin placing the blocks with the mortar you will want to do a dry run or take a "reading" of your glass block layout. This means to put a layer of glass blocks in and use cardboard or wood to simulate the mortar. Lay one layer, or row, horizontal (across the bottom) and one row vertical on the window sills. Remember to use something to simulate the mortar between the blocks. By laying these two rows you will accomplish two things: You can make pencil marks as to where the blocks are and you will also make sure that your blocks will fit properly before it is too late.
Once you have laid your dry run, have made your marks and checked for fit you are ready to begin installing your blocks. Mix your mortar to a consistency about the same as bread dough. If it is too wet it will not stay in place, too thick (or dry) it will cause the blocks to slide, or "float", and create uneven mortar joints. Spread a layer of mortar on the window sill and level it with your trowel. Place some mortar on the side of the window sill where your first block will be against it. Take your first block and put a layer of mortar on the vertical edge that will be facing away from the window sill; this will be for the next glass block. NOTE: If you are installing on a wooden frame do not use mortar directly on the wood; lay your first row directly on the sill and against the sides. Use wooden shims to make a tight fit.
Continue placing the blocks by putting a layer of mortar on the vertical side of the blocks. Use the marks that you made on the wall to line up the mortar and rows. When you finish with your first row check it either by eye or by level to be sure it is straight. You can tap the blocks gently with the handle of your trowel if necessary. Lay a bed of mortar on the top of this row making sure to fill all holes between the glass blocks.
Lay each row of blocks in the same manner: lay bed of mortar, lay mortar on side of frame for first block, apply mortar to side of block and place block. Check each row to be sure it is level and that it lines up with your marks. Let the blocks "settle" for about two hours. This will allow the blocks to settle into the mortar and the mortar to dry. When it is about dry use a striking tool to finish the mortar and give it a professional look. After the mortar has had a long enough time to set up use a soft towel and water to remove any excess mortar from the glass blocks. Do not use an abrasive cleaner or steel wool as this will permanently scratch your new glass blocks.
On a wood-framed window you will need to carefully nail some wood molding to the house frame so it overlaps the blocks by about a half inch as this will hold the blocks in place. Use caulk to seal the glass blocks on both interior and exterior sides.
