News from the Block, Innovate Building Solutions Blog
News from the Block, Innovate Building Solutions Blog
Bathroom, Kitchen, Basement Design & Remodeling Ideas for the Nicest Home or Business on the Block
Bathroom, Kitchen, Basement Design & Remodeling Ideas for the Nicest Home or Business on the Block

5 Secrets Nobody Tells You about Glass Block Windows

5 secrets nobody tells you about glass block windows

If you call or walk in your local home center or building material supply store and ask someone a question about glass block window design, fabrication or dare I say it – installation – you’ll be lucky if they even know if they carry glass blocks in stock (by the way in most cases they don’t carry this material)! Maybe you’ve got a unique design or a tough installation question and you not only need basic advice you need a “masters-level” input (or the “untold story”) on how to work with this classic material.

If you’re looking for deeper input you’ve come to the right place. In this article, we’ll take a look at 5 little known secrets about glass block windows which can help you get an improved design and quality of the installation. Let’s dig in!

Little Known Secret #1 – There are good, better and best ways to fabricate (put together) glass block windows

Glass block window fabrication is definitely an area where a “one size fits all” approach doesn’t make sense. In most cases it is best to prefabricate (or manufacture beforehand) a glass block window before you go to install it into a rough opening. The reason for this is it’s very difficult to try to put the blocks together unit by unit inside the window sash. In choosing a fabrication method it is best to ask yourself, “Do I want one which will blend the best with the brickwork or the home or do I need the highest level of security, energy or water protection I can get? Would it be best for this project to choose the cheapest system?” These questions will drive whether you want to use the good, better or best fabrication methods. Let’s look at the advantages and disadvantages of these 3 types of prefabrication approaches.

  • The “good” – silicone glass block windows – The silicone method of fabrication is cheapest because the blocks are butted together (with nothing filled between the inside cavities of the blocks) and can give an all glass look. On the flip side though they provide the lowest level of energy efficiency, security and are the least water tight.

glass block window using a silicone fabrication method

  • The “better” – the classic mortared together glass block window – This is the granddaddy of prefabbed windows. The window is built with a mortar and sand mix between the blocks. Its blends nicely with a masonry foundation and does a good job with securing a property. The challenge with this type of window is the mortar joints can sometimes crack if the foundation shifts.

glass block window with the mortar fabrication method

  • The “best” a Protect All glass block window – The “Protect All” window uses vinyl spacers vertically and horizontally between the blocks and has a 1/8” silicone bead on the outside. This window is practically impossible to break apart, is 20% more energy efficient and is more watertight than the mortared or silicone only windows discussed above. The negative is its initial purchase price is more expensive than the 2 other options.

strongest glass block window fabrication method protect all system

Little Know Secret #2 – Increasingly popular non-patterned (see-through) blocks can be offer complete privacy

You may be saying at this point, “Mike, this little known fact makes absolutely no sense at all! Why would I want a see-through block pattern and how can they be completely private?” The reason see-through blocks are growing in popularity is some people have gotten tired of the standard wavy patterns and are looking for a more modern looking block. With this being said many people are using glass block windows in bathrooms, showers or kitchens or other places where they want privacy so how could they even consider using a see-through block? Well now you can get a one side frosted or satin finished glass block which provides the modern contemporary look on the inside while maintaining complete privacy on the outside – a two for one special!

clear glass block window with a satin frosted exterior surface for privacy
Clear block window in a kitchen with a satin frosted finish for privacy

Little Know Fact #3 – The strongest glass block windows are not put together with mortar!   

Now this little known fact may seem totally nuts. When we make comments about something being sturdy you may say something like “it’s built like a brick wall (and brick walls are built with mortar!). So – how could there be a glass block window which provides more strength than a mortared variety? Well with the Protect All glass block window system the vinyl spacers through the window are actually much tougher to break apart than mortar.

Prefabricated protect all glass block window with vinyl spacers between the blocks
prefabricated protect all glass block window with vinyl spacers between the blocks

This system is so strong that it is safe to ship panels across the country with a standard trucking company. If you did this with a traditional mortared window I would almost guarantee you the prefabricated glass block window panel would arrive broken!

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Little Know Fact #4 – Glass block windows are emerging beyond the look associated with re-runs of Miami Vice

Glass blocks came to be associated with the 1980’s art-deco style right out of a scene with Sonny Crockett and Rico Tubbs on Miami Vice. While you still can get this classic wavy pattern look with glass blocks – the material has evolved with more modern patterns, textures and even the opportunity to mix and match colors to create a stained glass type of look (there are 104 different color and finish selections to choose from!).

Glass block window using a high privacy blocks in multiple colors in a contemporary setting in columbus ohio

This ability to add different textures and sizes in a window which is strong and durable is a unique advantage of glass blocks over traditional windows.

different glass block sizes and textures in a prarie style glass block window in michigan

Little Know Fact #5 – You don’t have to be a skilled mason to install a glass block window into a new home or room addition

With the invention of vinyl framed glass block windows you don’t need to be a skilled mason to install these windows. A premade glass block window built into a vinyl frame with a nailing fin can be installed into any rough opening with the same tools you would use to install any traditional new construction window.

nailing fin vinyl framed new construction glass block window is easy to install


The reality is the glass block window has evolved – but the education about the fabrication, design and installation options has not been communicated well. Which of these 5 little known facts about glass block windows are news to you? If you want to get “masters-level” input on how to design, fabricate or install these windows please reach out at the numbers below.


For design and fabrication help and nationwide glass block window supply call Innovate Building Solutions at 877-668-5888. For a local installation contact Cleveland Glass Block (216-531-6363), West Side Glass Block (216-398-1020) or Columbus Glass Block (614-252-5888)

If you’re a remodeler or builder and want practical advice on remodeling products, industry trends, marketing and sales tips to grow your business (and cut day to day hassles), start reading my newest blog – Innovate Builders Blog. It’s packed with ideas you can use now. Click here to Sign Up for the Innovate Builders Blog.

Mike Foti

President of Innovate Building Solutions a nationwide supplier and regional (Cleveland and Columbus) remodeling contractors. Some of our product lines include glass counters, floors, backsplashes, glass blocks and grout free shower and tub wall panels

Comments (12)

  • I’m looking for a way to clean the mortar between my glass block shower wall. There is no mold only slight discoloring I think from the minerals in our Las Vegas water. I have searched and have found quite a few methods. Looking for your opinion for a “Do it Yourself” plan.


  • Ed – there are glass blocks which could be built into a hurricane /impact resistant glass block window. To get you a cost we will need to learn the number of colored glass blocks you’d like in this window. Michelle in our office is due to call you. Mike

  • I will be building a new block home in Sebastian Florida next year and am interested in colored glass block for the pool area. Are the prefabricated windows hurricane/impact resistant? I will need 6 windows 24″ wide X 64″ tall. What is the cost?

  • Andy – a glass block shower wall would not need to be treated any differently than any other type of glass wall in a shower. Usually glass blocks are set on the curb portion of a shower pan or if there is no pan (this can be the case in a one level wet room system) can be set directly on the floor. You don’t need a concrete footer to do this type of project. Our company can assist you with the design of this wall and supplying premade glass block wall panels and a shower pan to put this entire system together. Let me know if I can help further. – Mike

  • Hi – I want to put in a glass block shower wall (interior) and my architect that glass block is technically masonry, and therefore requires a foundation and footer be poured beneath the floor. True?

  • Zanne – good question! There are 2 ways you can do a bathroom window – either as a vinyl framed window or as a frameless window. We can make the vinyl framed windows various sizes (by using different blocks) for you – but usually in a remodeling projects in a wood framed opening we normally go with a frameless window and then use insulating foam around the edges of the window. I will ask Lillie in our office to reach out to you via email to talk further about this. Thanks for your question – Mike

  • Hi, I want to put a glass block window inside a shower on an exterior wall of a house built in the 1940s. I’m replacing an old steel window that is approximately 22.75″W x 34.75″H (I don’t know what the rough opening size is because I’m not at the right stage in the process to take apart any windows). I would like to avoid changing the footprint of the window on the outside (and don’t want to have to change any of the exterior trim or siding if possible).

    I was looking at a DIY Provantage kit so I could have a hopper vent/window at least 16″+ up from the bottom of the window. But, that system is only for blocks that are 4″ thick, which will make them very heavy. Additionally, they will be 24″ x 31″ rough opening so they will be wide but not tall enough. Additionally, they will need to be finished with a type of grout that I can’t seem to find. I saw a pre-fab REDI2SET glass block window that has a 21″ x 36″ rough opening (which I think I could work with) except it is frameless and requires mortar.

    If I could get one prefab that will fit without too much adjustment to the frame and maybe that already has vinyl around it or can have vinyl perimeter channels set in place with 3″ thick glass blocks (so it will be lighter but still sturdy) I’d be interested in pricing. I couldn’t even find anyone in my area who would make tempered glass windows for this application and a regular window would have to be tempered to be in a shower.

    Any suggestions?

    I have difficulty hearing people on the phone so I prefer e-mail.

  • Linda – thanks for your question. The bubble style glass blocks come in an 8 x 8 dimension so we could do a 48 x 32 window or a 48 x 40 window. Another option if you like the bubble block (and you don’t want to change the opening size) would be to use a 4″ “wave” pattern row in the middle. If you want to learn more about this give us a call!

  • Linda – thanks for your interest in our products. We ship them across the country so we can certainly help you. Is there anything in particular you like? Feel free also to call us at 877-668-5888.

  • Hi Mike, I live in Lexington, KY and my contractor talked to me about replacing my tub in one of the bathrooms with a doorless shower. He referred to it as a Turkish shower. How can we get your products in Lexington, KY?

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