Crazing on acrylic block window

Noticed tiny cracks on the inside of the blocks, and have never seen this before. After a little research, found a manufacturer site that said using harsh cleaners like Tilex or ones with petroleum products could cause cracks over time and void the warranty.
It also says not to clean blocks in the hot sun (the window faces west)

Just thought I’d share this info in case someone runs into this.

Acrylic ,not glass ?
Why would anyone use a plastic glass block ?

It is bound to be scratchy over time no matter what .

See these all the time on newer homes around here. Lighter, cheaper, etc.
Just what contractors want… cheaper:)

I was looking at info for the buyer, and a 4 x4 window is about $600 (not counting installation)
This one is 4x6

It always gets the buyer’s attention when I tap on the windows and see the startled looks. You mean they’re not glass???

So are you checking the framing and structure to make sure they are using lintels for support ?
In Chicago builders seem to think Glass Block is structural the idea of weaker plastic blocks makes me nervous ,not to mention the limited life.

Glass stays clear over time however any plastic gets that cloudy-yellow shade over time and looks terrible.
Those two facts alone make me give the product a thumbs down.

Agree on the limited life, but they’re windows Bob… not structural at all.

Google acrylic block windows for more info on the subject

Did not lookup pricing but know plastic typically costs more than glass so not sure I see the point but to each their own.

Well, if glass WAS cheaper, wouldn’t the contractors use it? I have NEVER seen a GC use something that is more expensive in tract homes than they can get away with.
By the time they pay a mason to install the glass blocks in mortar, I’m sure the plastic pre-fab would pencil out to be less expensive.
Actually, there may be another reason and that is energy efficiency. Plastic is less conductive than glass, and the acrylic windows are more efficient.

If you ever replaced glass with plastic on a lobby door you would know what I mean by yuuuck.

I don’t like them either, just pointing out cost and energy efficiency as the reason GC’s use them in tract homes.

[quote=“jhugenroth, post:9, topic:87419”]

I have NEVER seen a GC use something that is more expensive in tract homes than they can get away with.

Amen to that