7 Problems with Glass Block Windows That You Can’t Avoid

If you like to follow design blogs and social media accounts of popular home designers, you may have noticed that glass block windows are making a comeback. Glass block windows were all the rage in the 80s but have fallen out of favor.

Back then they were used frequently for shower walls and room dividers as well as outside windows. They are now showing up on design blogs and social media as vintage style exterior windows as well as room dividers, accent walls, and shower walls.

glass block windows

Glass block windows originated at the turn of the 20th century. Many factories were built with glass block windows because the glass blocks were opaque but let in some natural light so that the factories weren’t totally dark. Homeowners love the vintage look of glass block windows but others think it looks old fashioned and dated no matter what designers think .

If you’re considering adding glass block windows to your home as exterior windows, accent walls, dividers or in the shower there are some things that you should know. If you really love the look of glass block windows you should know these problems before you commit.

They’re Heavier Than Other Windows

Glass block windows are much heavier than other types of glass windows. If you’re planning on using glass blocks for exterior windows or exterior walls that could cause structural problems with your home. Using them in interior spaces can also put a lot of weight on your walls and floors that could end up damaging your foundation.

If you are committed to  using glass block windows make sure that you have a professional contractor assess whether or not your home can stand the extra weight before you install.

Difficult To Replace

Because glass block windows need to be mortared together in order to make a full window or a wall they are very difficult to replace. If one of the pieces of glass cracks or splinters it could be practically impossible to remove that one piece and replace it, especially if it’s at the bottom of the window.

If that happens the entire window or wall would need to be pulled down and replaced and that would be very expensive.

No Natural Ventilation

Glass block windows have no natural ventilation. Because a glass block window is a pile of glass cubes mortared together the mortar forms a super tight seal between the pieces of glass. That means that no air can pass through the space between the blocks of glass.

In an indoor environment where glass block windows are used for accent walls, room dividers or shower walls that means that the air flow in the room will be obstructed. When that happens the air conditioner or heater will have to work harder to circulate indoor air and that will cost homeowners more on their energy bills.

Can’t Open Them

Another major problem with using glass block windows as exterior windows is that they can’t be opened. While they do provide some natural light and warmt, they don’t provide any fresh air. Exterior windows made from glass blocks are more like see through glass walls than actual windows and that makes them not ideal for exterior windows.

Exterior windows in a home should be opened to let in fresh air as well as light and sunshine.

Privacy Issues

Glass block windows are opaque. People assume that the cloudy glass provides total privacy and that people can’t see through it. But in reality the amount of privacy depends on the way that the glass is made. Often the glass does allow people outside to see things that people on the other side of the window probably don’t want them to see.

When glass block windows are used as shower walls or in the bathroom, or when they are used as exterior windows, they don’t really provide very much privacy at all. A regular thermal pane window with a decorative frosting over it is much better for privacy than a glass block window. And a regular window can be opened to ventilate the bathroom and let out some of the moist air so that mold and bacteria don’t grow.

They Can Crack

Glass blocks are heavy and they are fragile. They can crack, shatter, chip and become damaged just like a mirror or other glass can. But chips, cracks or damage in a glass block window can cause the entire window or glass block wall to become unstable. And if those glass bricks all come tumbling down they can cause a lot of damage.

broken glass block window

The glass block window or wall will also be very expensive to fix. Because of the potential for damage, and the potential for injury if the glass block wall or glass block window does crack, shatter, or chip. It’s not recommended that parents have glass block windows or walls in home with young children that might break the glass or get injured by the glass.

They Absorb Heat

With temperatures rising around the country every year homeowners should be doing everything possible to cool down their homes. But glass block windows and walls absorb heat and make the interiors of homes warmer. So homeowners that are facing rising summer temperatures and intense summer heat should definitely avoid glass block windows and walls.

The heat absorption of the glass combined with the lack of ventilation will make your home extremely warm and difficult and expensive to cool if you have exterior glass block windows or a glass block wall in a sunny area inside the home.

Feldco is Chicago’s source for window replacement. Feldco has replaced windows all across the Chicago area over the past 40 years. Get a free quote to get started on your window replacement project with Feldco.

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