Picture of the basement glass block window replacement 1, close up after installation.

How to Install Glass Block Windows, with Pictures

We replaced ten basement windows with these Redi2set pre assembled glass block window panels, pictured below.  You save the hardship of laying individual blocks when installing these eight block pre-formed units.  Major time saver.  In this post, we share our experience and hints we found on how to install glass block windows in our home basement.

We’ve included pictures we took throughout the project. Then, we peppered tips and insights among them that we learned along the way. Enjoy.

Picture of the Redi2Set preassembled glass block window panels and glass block mortar for installing them.
Redi2Set preassembled glass block window panels and glass block mortar for installing them.

How to Install Glass Block Windows: Tools and Supplies You Will Need

Shims

You’ll need lots of wooden shims to correctly position and level the windows in the wall window ports.  As the shims are wedge shaped, it’s easy to correctly level the new window on them.  When placed on the bottom, the window can be raised slightly by driving in the shim a bit further.  It can be lowered by pulling the shim out a little.  In the pictures below, we show how to use these shims to position each glass block window.  They hold the window in place while applying the mortar.

How to install glass block windows. Picture of the front view of a package of Nelson wood shims.
How to install glass block windows. Nelson wood shims, packaged, front view.

Chisels

You’ll also need a set of chisels of various blade sizes, from a quarter inch up to two inch widths.  Use these to chisel out any stubborn mortar that holds the old windows in place.  However, be careful not to chisel too deep, lest you damage the cinder blocks that comprise the surrounding wall.

A Buddy

Glass block windows are heavy and unwieldy.  This can make them difficult to lift into position and position properly by yourself.  So, we recommend that you have a friend available to help with the lifting.

A Stepladder

We used a three-step stepladder when lifting our glass block windows into place. Since basement window ports tend to be several feet off the floor, a stepladder is quite useful.

Mortar and Gravel

They make fine-grain mortar that matched our white basement walls.

A Paint Stirrer

A paint stirrer or any long, thin piece of wood would do.  This comes in handy to push the mortar into the spaces around the new window.





Pry Bars of Various Sizes (Also Known as Crowbars)

Use pry bars to pry out the old window frames, before installing the new glass block panels.  You may need sizes ranging from foot-long pry bars to three foot lengths.  This depends on how strongly your old frames have been cemented in.

A Can of Cement Sealant

Choose a transparent one, or one that won’t change appreciably the color of the mortar you’ve selected.  Seal all mortar joints surrounding your new windows after installation, to help keep it strong for decades to come.

How to Install Glass Block Windows: Basement Window One Replacement

A little scared to begin, as we had never replaced a basement window before.  So we spent some minutes just staring at this, the first one to remove, for several minutes before starting.   This inspection showed that the old soft metal window frames were simply cemented into place.  In our case, they were sixty-five years old.  So the mortar holding them fell away with very little effort, once we started pulling on the frames.

Picture of an old metal framed basement window 1 prior to replacement.
Old metal framed basement window 1 prior to replacement.

We first removed the glass and metal window assembly from the frame. See this in the top area of the next picture.  Then, we chiseled out the surrounding metal frame.  The metal strip pieces shown in the bottom half of the next picture were the frame.  However getting them out required that we bend them up quite a bit.  No problem though, as these would not be used in the new window installation.

How to install glass block windows. Picture of old basement window 1 removed from wall opening, showing its pieces on the floor.
How to install glass block windows. Old basement window 1 removed from wall opening, showing its pieces on the floor.

 

Picture of the first basement glass block window replacement 1, positioned in exterior wall hole and shimmed, prior to mortar application.
The first basement glass block window 1 raised into position. It has been shimmed, leveled and plumbed. It’s ready for mortaring.

 

How to install glass block windows. Picture of the basement glass block window replacement 1, white mortar applied and wooden shims removed. Installation complete.
How to install glass block windows. Basement glass block window replacement 1, white mortar applied and wooden shims removed. Installation complete.




Basement Glass Block Window Two Replacement

Picture of the 2nd old basement window to be replaced.
Old basement window 2 to be replaced.

 

How to install glass block windows. Picture of the Old basement window 2 removed, showing the open wall hole to the outside.
How to install glass block windows. Old basement window 2 removed, showing the open wall hole to the outside.

 

Picture of the basement glass block window replacement 2, positioned and shimmed, with shims highlighted.
Basement glass block window replacement 2, positioned and shimmed, with shims highlighted.

 

How to install glass block windows. Picture of basement glass block window replacement 2, shims removed. It's done.
How to install glass block windows. Basement glass block window replacement 2, shims removed. It’s done.

How to Install Glass Block Windows: Window Three Replacement

The next four windows were located on the north side of our home.

Picture of the old basement window 3 to be replaced.
Old basement window 3 to be replaced.

 

How to install glass block windows. Picture of the Basement glass block window replacement 3, mortar applied Installation complete.
How to install glass block windows. Basement glass block window replacement 3, mortar applied. Installation complete.

Basement Window Four Replacement

Notice that with this window, we began writing the window number underneath each replacement window target.  Helps with matching the roll of pictures up with the windows to which they apply.

Picture of the old basement window 4 to be replaced.
Old basement window 4 to be replaced.

Particularly hard removing the old metal frame for this window. Had to apply lots of back grease (whole body effort) to pry it out of the cement with a crowbar.  Unfortunately, we marked up some of the cinder block corner on the right side of the new window.  Pace an old scrap piece of wood beneath the crowbar neck.  This keep it from pressing directly on the cement blocks surrounding the window.  So, you are less likely to mar the surrounding blocks if you take this precaution. 

How to install glass block windows. Picture of the basement glass block window replacement 4, shimmed and positioned.

How to install glass block windows. Basement glass block window replacement 4, shimmed and positioned.

On this side of the house, there were thick shrubs growing on the outside of the replacement window locations.  So, pictures of most of the glass block windows from the house exterior could not be taken.  However, below, we did get one or two from outside of window 10.





Had to be careful while excising the rusted frame for window 4.  It was hard not to break the PVC water pipe feeding our water heater.  See this near the top of the next picture.

How to install glass block windows. Picture of basement glass block window replacement 4, mortar applied, shims removed, installation complete.
How to install glass block windows. Basement glass block window replacement 4, mortar applied, shims removed, installation complete.

Basement Window Five Replacement

Fortunately, most of the work for this window we could do from inside the basement.  Otherwise we would have had to work around our central air conditioning compressor.  That was located just outside window 5, as shown next.

Picture of old basement window 5 to be replaced.
Old basement window 5 to be replaced.

 

How to install glass block windows. Picture of the basement glass block window replacement 5, shimmed and positioned.
How to install glass block windows. Basement glass block window replacement 5, shimmed and positioned.

As mentioned, we slightly damaged the surrounding cinder block on some of the windows.  But we were able to fix those nicks. We filled them in with a bit of the white mortar used also for setting the block windows.  We applied it with a right-angle trowel.  Then once dry, we covered it with a little basement wall white paint.  Easy to fix.  But we suggest avoiding that problem in the first place. Just be careful how your pry the old windows out.  Don’t use too much elbow grease on them.

Picture of basement glass block window replacement 5, mortar applied, shims removed, installation finished.
Basement glass block window replacement 5, mortar applied, shims removed, installation finished.




How to Install Glass Block Windows: Window Six Replacement

Window six presented its own set of unique issues.  First, we worked around the big blue well pressure tank.  See this tank in the lower right corner of the next picture.  Plus, outside the house, the trunk of a tall arborvitae bush blocked access.  But we didn’t don’t mind getting a little dirty and cold. Working outside plus leaning over a water tank inside wasn’t too bad.  Projects like this should go off without incident, although perhaps not so easily.

How to install glass block windows. Picture of decades old, rusted basement window 6 to be replaced.
How to install glass block windows. Decades old and rusted basement window 6 to be replaced.

 

Picture of basement glass block window replacement 6, shimmed and positioned.
Basement glass block window replacement 6, shimmed and positioned.

 

How to install glass block windows. Picture of the Basement Glass Block Window Replacement 6, with white mortar applied and shims removed.
How to install glass block windows. Basement Glass Block Window Replacement 6, with white mortar applied and shims removed.

Basement Window Seven Replacement

The rest of the replacement windows were installed on the south side of the house.  These first two went in quite easily.  No outside obstacles.  In fact, there was just an empty patio out there.  No plants or other obstructions in front of windows seven and eight.  A wooden porch covered the last two, including the block window with the dryer vent port.

 

Picture of the old, literally crumbling basement window 7, prior to replacement.
Old, literally crumbling basement window 7, prior to replacement.

 

How to install glass block windows. Picture of the binside view of the asement glass block window replacement 7, mortar applied and shims removed, installation done.
How to install glass block windows. Basement glass block window replacement 7, mortar applied and shims removed, installation done, inside view.

 

Picture of the exterior side of the basement glass block window replacement 7, with the shims removed, and installation complete.
Glass block window replacement 7, shims removed, installation complete, outside view.

Basement Window Eight Replacement

How to install glass block windows. Picture of old basement window 8, to be replaced.
How to install glass block windows. Old basement window 8, to be replaced.

 

Picture of the Basement glass block window replacement 8, shims removed, installation complete, inside view.
Basement glass block window replacement 8, shims removed, installation complete, inside view.

 

How to install glass block windows. Picture of the basement glass block window replacement 8, shims removed, installation complete, exterior view.
How to install glass block windows. Basement glass block window replacement 8, shims removed, installation complete, exterior view.




How to Install Glass Block Windows: Window Nine Replacement

Picture of the old basement window 9, to be replaced.
Old basement window 9, to be replaced.

 

How to install glass block windows. Picture of the Basement glass block window replacement 9, shims removed, installation complete.
How to install glass block windows. Basement glass block window replacement 9, shims removed, installation complete.

Basement Window Ten Replacement

This window includes a dryer vent opening.  Make sure when installing this special window that you have enough clearance on the outside. The vent needs that.  There should be nothing within a couple feet of the opening.  This assures good air flow out of the vent.

Picture of the old Basement Window 10, with the dryer vent, to be replaced.
Old basement Window 10, with the dryer vent, to be replaced.

Below is the new glass block window with built-in dryer vent.

How to install glass block windows. Picture of the basement glass block window replacement 10, with shims removed, installation complete.
How to install glass block windows. Basement glass block window replacement 10, with shims removed, installation complete.

How to Install Glass Block Windows: Cleanup Procedures

Patch Up the Walls and Window Sills

As mentioned above, during installation, we broke a few small pieces out of the bricks in the wall a bit.  It’s hard not to, while prying out the old windows given how stuck in they were.  Cleanup time counts the time to repair these small imperfections.  See these as shown in the window 9 pictures above.

Then, with all windows done, we went around patching any dents around them.

Finally, after all mortar dried, we applied a bit of basement white paint.  Paint around the inside of the glass block windows, to match your basement walls. Use a clear sealant on the outside mortar.

Haul Away Old Windows, Frames, and Other Debris

We loaded up all the waste and debris from this project into the back of a pickup truck. Then, we drove it to the local dump.

Seal the Mortar, Once it Hardens

Several days after cementing the glass block panels in place, apply a cement sealant.  Cover all new mortar surfaces around the windows. Be sure to cover well the outside side; the side exposed to the elements.

How to Install Glass Block Windows: Suggested Reading

  1. How To Change A Bathroom Sink Faucet
  2. Electric Baseboard Heaters Installation Help, Hints, Tips, Advice
  3. How To Replace a Toilet Seat Tips
  4. Setting Windows 10 Voice, Text to Speech
  5. Installing a New WiFi Router, How To
  6. Zircon Stud Sensor e50 Stud Finder Detector Review
  7. How to Install and Set Up Cortana App for Microsoft Invoke Smart Speaker
  8. How to Change Windows 10 COM Port Number for USB Modem

References for How to Install Glass Block Windows

  1. Glass block, a Good Choice for Basement Windows  from The Weekly Fix
  2. How to Put In a Glass Block Window   from DoItYourself.com
  3. Installing Glass Block Windows, with Pictures   from WikiHow

Revision History

  • 2019-04-05: Tweaked key phrase targeting and removed ad code.
  • 2018-01-21: Originally published.