Glass Block Windows 101

Choosing to install Glass Block windows is a great way to subtly improve your room but it should be done with planning and a solid understanding of what you hope to accomplish with what could transform into a new space in your home.

A properly installed window tends to brighten up the room while also keeping bugs and critters out.  Basements, bathrooms and garages are common areas for glass block.

The best time do have the windows installed is before you choose to remodel the inside of your house.  This is because any drywall or tile that will be adjacent to your new window could become damaged or not fit well against your new window.  It is easy for a drywaller or tile professional to make modifications to your project, but more difficult to modify a glass block window in certain cases.

Common Reasons for Choosing Glass Block


When a glass block window is installed with old-world craftsmanship techniques, it keeps out criminals, bugs and other small creatures. Think of the window as a continuation of a wall. We use mortar between the blocks as well as around the window to give a nice tight finish.  Because it’s masonry, it’s hard to replace so keep in mind that once this window goes in, it should never be taken out.

Water Protection

Basement windows made out of wood (which is organic) are always secured to concrete.  When water sits against that concrete it rots out the wood.  By replacing that wood with mortar and glass (inorganic), there is nothing organic to rot out.

Installing glass block in a shower area is a much better alternative than a traditional window. Common challenges with shower windows include mold patches, rotten wood and a leaky window. Glass Block windows are designed to shed water from both the inside and the outside. We recommend applying grout sealant annually for bathroom installs to
get the most out of your new window.


Glass block is about as efficient as a thermal pane window but not as efficient as a triple-pane window. Each block is
engineered so there’s a pocket inside of the block. This makes it so that there is essentially two-panes of glass with an air pocket between them that creates higher efficiency.

A properly installed glass block should last as long as your home does and magnify outside light into any room that faces south, west or east.  Northern facing windows do not get direct sun and therefore will not magnify light.

Also see: Venting Glass Block Windows

Posted in

Leave a Comment

You must be logged in to post a comment.