Domestic vs Imported Glass Block

The argument about which block is better is another arguing point between competing glass block companies.

When deciding which company to use, "who has the better product" should never come before "who provides the best service". I'm not saying you can't have both, just that the decision you make should be relative to the product and the service combined.

For the purpose of this post, I will restrict the comparison to residential products and more specifically, glass block intended for windows.

Who is the best glass block manufacturer? Well... there is a lot more to consider now. Do you base it on "variety", "quality", "performance", "cost", or something else?

Since I type a little more than ten words per minute I'm not going to provide actual test data but at the end of this post I will add links to each of the manufacturer's web sites for you to research. This is one of those points where you will just have to take my word for it.

I'm also going to limit my comment to the three most common manufacturers. Pittsburgh Corning, Mulia Inc. and Weck. You can find distributors of each of these manufactures just about anywhere in the United States.

Glass blocks are measured primarily by Heat Transmission (U-Value), Thermal Resistance (R-Value), Visible Light Transmission (VLT), and Sound Transmission (STC).

Understanding these measures and their values are important. The lower the value in some measures is better and the higher value in other measures is better.

While I type this, I have specification books from each of our three comparative manufacturers. I will list the measure, then in the order of better performance I will list the manufacturers. I am comparing only eight inch square block, three inch thick (a.k.a 8 X 8 X 3).

U-Value (lower is better): Mulia (.51), Weck (.53), PC (.57)
R-Value (higher is better): Mulia (1.95), Weck (1.89), PC (1.75)
VLT % (lower is better): Mulia (65), PC (75), Weck (77)
STC % (higher is better): Weck (41), Mulia (35), PC (31)

What does this information mean? Well, to be honest, absolutely nothing. The performance variations between the manufacturers are so slight that in practical use, they are barely measurable and not even noticeable.

For the performance category we have just established that there are no measurable difference between these three manufacturers.

Quality? I'm afraid I don't have any production tolerance standards from each of the manufacturers. Having handled thousands or even tens of thousands of individual glass blocks; I can tell you that they all have loose tolerances in size and shape. Each has exhibited variations in thickness and squareness. For the purpose of glass block windows, you'll have to take my word that each are equal or the differences between are not measurable.

Variety? Each manufacturer has a long list of available patterns and sizes. For the sake of consistency, since we are talking about residential glass block windows, we will count the variety of patterns available in 8 X 8 X 3 inch glass blocks.

Mulia: 9
Weck: 4
Pittsburgh Corning: 2


On to cost...
This isn't as easy as it sounds. I will not publish MSRPs because each distributor may charge differently based on several different factors. I will say only that I have distributed each product and when I maintain a particular mark up percentage based on distributor prices, Pittsburgh Corning is the most expensive, Weck is a close second and Mulia is the least expensive. Pittsburgh Corning and Weck are closer in price than either of them is to Mulia, if that makes any sense.

Have we determined who the best manufacturer is?

I believe we have reviewed enough information to lessen the importance of "product" in your decision.

The bottom line is, find a reputable company to do business with. No matter the product, find the company with the most experience, best warranty, best BBB rating and spend your money there.


Sources:
http://pittsburghcorning.com/files/product-literature/residential-products-living-with-glass_gb-224.pdf

http://www.muliainc.com/glassblock/products/MuliaGlassblockArchSpec.pdf

http://glashaus.com/english/weck/american/ai-1a.htm


Manufacturer's Webs (not a complete list):

http://pittsburghcorning.com/ Pittsburgh Corning
http://www.muliainc.com/glassblock/ Mulia Inc.
http://www.glashaus.com/ Weck
http://www.jhglassblock.com.cn/en/1about/1intro.htm Jinghua
http://www.vanagb.com/seveshome.html Vetroarredo