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

Pittsburgh Corning to Stop Glass Block Manufacturing – Now What?

Pittsburgh Corning to Stop Manufacturing Glass Blocks in Port Alleghany Pennsylvania


Updated February 22, 2019

Another American company (Pittsburgh Corning the only domestic manufacturer of glass blocks) decides to idle a 79 year old plant in Port Allegany Pennsylvania and permanently lay off 75 workers. As someone who has bought Pittsburgh Corning (P.C) products, likes glass blocks as a building material or is a fan of U.S. made products here’s 3 questions you’ll want the answers to:

  • (Question 1) Why did Pittsburgh Corning close their United States manufacturing plant making glass blocks? Could this plant closing have been stopped?
  • (Question 2) I already have a window, shower wall or commercial project made with Pittsburgh Corning glass blocks (or was planning a future project with P.C. materials). What should I do now?
  • (Question 3) What is the future of the glass block industry? Can I still use this product for my home or commercial building? What do the product options look like without Pittsburgh Corning in the market? Is the future of this industry bright or bleak?

I’ll explore this decision Pittsburgh Corning made (now almost 3 years ago) and give you a feeling how the market has evolved today.


Question 1 – What reason did Pittsburgh Corning give for leaving the glass block business? Would a different result have been possible?

According to the Pittsburgh Corning’s Global Vice President John Caverno their glass block business had been unprofitable for 8 years because it never recovered from the crash in the housing market and foreign imports were hurting their business. These 2 problems cited by the company beg the question – why did this company not recover from the housing market which was slow several years ago? Why were they hurt by foreign imports when historically they have been the market share leader? First let’s look at new home and remodeling markets.

The remodeling, new home markets and commercial construction markets today are enjoying a resurgence. You can notice this by seeing how long it takes to get a contractor out to your home for an estimate. Interest rates are near historical lows and the new home builders who survived the housing crash which started about 8 years ago are busy again. The Residential Remodeling Index (RRI) which bottomed out in 2010 and 2011 is now 3.1% higher than its all-time high which occurred in 2007. In a nutshell construction has been on an upswing.

Foreign manufacturers have certainly impacted many United States industries but why have the foreign glass block manufacturers gained market share against Pittsburgh Corning? Although I won’t claim to be an “inside expert” on all things related to this company (note: I own one business who has been buying from Pittsburgh Corning since the day it was started and one who stopped buying the majority of our glass blocks from P.C. about 9 years ago) I can give the top 3 reasons I believe Pittsburgh Corning ending up needing to exit this business:

  • Lack of investment – Pittsburgh Corning’s plant and equipment had gotten old and instead of reinvesting they continued to produce in an antiquated plant. Theystarted looking for a buyer (too late) and their market position deteriorated before anyone provided an acceptable offer to purchase the business and rebuild the Port Alleghany plant. Basically – they lived ‘high and mighty off their past laurels – the world past them by – then they imploded (not a pretty picture, but true – IMHO).
  • Lack of  residential market-driven innovation – New product ideas need to come from customers who use or specify the product. While Pittsburgh Corning developed new items over their final 8 years the most important residential advancements have come from foreign manufacturers (products like thinner glass blocks for showers, colored glass blocks, textured and 3 dimensional blocks – see question 3 for more info on these products) were not embraced by this United States manufacturer. They did develop some interesting products for the architectural markets (like tornado and blasts resistant windows) but their products for consumers and new home builders have been mostly stagnant. They fell behind the times. The foreign companies started kicking their butts. Check out below the thinner glass blocks and minimalistic and modern glass blocks made by foreign manufacturers today.
Thinner glass blocks for shower walls
Thinner glass blocks for shower walls
Textured glass block tiles
Mosaic tile textured glass blocks in the background of this living room in “nordica” and “non-colored” units
  • Lack of love – You may be asking what does love have to do with a serious manufacturing business? Well all customers want to feel appreciated or loved – whether they are a big or small buyer. For many years Pittsburgh Corning controlled the United States glass block industry and didn’t fully appreciate its distributors who install and supply glass blocks to homeowners and commercial businesses. I was once told by a V.P. of Sales if I wanted to choose another supplier for our glass block purchases he would have another company in my market ‘so fast my head would spin.’ (I always remembered that – and not in a fond way either). This caused a number of high level distribution customers (including one of my businesses) to buy from foreign manufacturers who treated them better and offered products focused on the residential market (like the thinner series wall blocks).

In my opinion if Pittsburgh Corning had invested in their plant sooner, developed more products for the new home and remodeling markets and worked better with their distributors I believe this plant would still be operating today.

Question 2 – I already have Pittsburgh Corning glass blocks in my home or commercial building now, what should I do now?

While many of the foreign glass blocks have similar patterns to Pittsburgh Corning (for example the “wave” pattern from Mulia Inc, an Indonesian manufacturer, looks similar to P.C’s “decora” pattern), their blocks are not a perfect match. The sand (a key element in the manufacturing of glass) of each country will create a different hue for the blocks and the patterns inside the glass are slightly different.

Glass block exterior wall in an upscale home
Replacement glass blocks should be matched to the original manufacturer for consistency

What I would recommend would be to call a former P.C. distributor or dealer and pick up some extra glass blocks and store them away in case yours are broken or vandalized (since this article was written 3 years ago there are very small supplies left – I know a few places you can get these blocks, but they are becoming a needle in a haystack). While it is possible common pattern blocks (like the Pittsburgh Corning “Decora” pattern) could be made in the future it is in my opinion unlikely since the foreign companies have patterns similar to this already (in fact, 3 years later no manufacturer has made the old Pittsburgh Corning patterns – with the exception of Vistabrik – discussed below).

For some of the commercial pattern glass blocks (like solid Vistabrik glass bricks or 90 minute fire rated glass blocks) there is one manufacturers – Seves Inc. who has introduced a “Vistablok” based on the Pittsburgh Corning old specifications.

Solid glass brick window with Vistabrik by Pittsburgh Corning
Solid glass bricks in a window

For these products my prediction is Pittsburgh Corning will at some point sell their molds and technology to one of the existing foreign companies. In the short run I would recommend any architect or builder with a project needing this material get their order placed now.

Question 3 – What is the future of the glass block industry like? Can I still use this product for a residential home or commercial building project? What do the product options look like without Pittsburgh Corning products being available?

I remember a number of years ago a V.P. of Sales and Marketing from Pittsburgh Corning saying in a distributor sales meeting, “The future is so bright we’ll need shades!” While it may seem odd that the future for glass blocks can be bright when the only United States manufacturing company leaves the industry there are a lot of cool things happening right now which are adding energy and growth to the use of glass blocks. Let’s take a peek at three product advancements:

  • Thinner glass blocks for shower and partition walls – While Pittsburgh Corning did not want to make thin glass blocks for walls (3 1/8” thick vs. the traditional 4” series) because their profit margins were better on the thicker blocks the Indonesian manufacturer (Mulia) has been making them for about 3 years. This product is not only more cost effective for the homeowner but it provides more room in a shower (if you’re shower is tight you know how important this is). These thinner shower blocks now are 90% of my business from 0% three years ago. If you refuse to make products which make more sense for customers (like Pittsburgh Corning did refusing to make the thinner blocks, you may end up with enough customers in the end and out of business!).
Thinner glass block shower wall with a stone solid surface shower pan
3 1/8″ thick thin line shower wall glass blocks
  •  Colored glass blocks – In the old days of the auto industry all cars were made in one color – black. The auto industry found out people like variation and therefore cars with different colors were introduced. While clear (non-colored) blocks are by far the largest portion of the market, the use of colored glass blocks (which is popular in Europe and Asia) is seeing tremendous growth in the United States. There are even colored and frosted blocks for added privacy. There are now over 100 different colors of blocks available in stock in the United States – this is waaaaaay more than when Pittsburgh Corning had 3 colors.
Purple color glass blocks in a modern shower
Colored glass blocks can make a project stand out
  •  3D textured and patterned glass blocks – Glass blocks are unique in their ability to not only separate spaces but to do it with a sense of style. Now an inventive new product from Seves Inc. allows 3D textured glass walls as well. How cool is this?
Textured glass blocks with a mosaic pattern in a contemporary home
Textured glass blocks with colors and a mosaic tile pattern


While things initially seem “doom and gloom” when a supplier leaves the market as I tell my kids “things are not as bad as they seem when they are bad or as good as they seem when they are good.” Stability is comforting – but markets and products advance and if companies don’t advance with them they can cease to exist.

The good news is several manufacturers are stepping into space left by Pittsburgh Corning and introducing exciting new products and increasing their marketing investments in the United States.

If you have some old Pittsburgh Corning blocks or need some specialty commercial glass blocks call the numbers below and get some replacement blocks while they last. If you are thinking of a glass block project don’t be afraid – the market is flush with new products which are rejuvenating this product.

For more information or a nationwide factory direct supply source call Innovate Building Solutions  (877-668-5888) or for a local installation project their divisions including Columbus Glass Block (614-252-5888), Cleveland Glass Block (216-531-6363), West Side Glass Block (216-398-1020) or Mid America Glass Block in Akron (330-633-2900).

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 (25)

  • Patrick – thanks for your input. I’ll need to go into the post to change this misspelling. It’s sad the PC plant hasn’t been converted to something else. We bought from PC for many years – but quite frankly they were cocky and didn’t listen to customers well – this is what caused their downfall IMHO. I hope this plant returns to it’s past glory with another manufacturer.


  • Port Allegany. Spell it correctly. A L L E G A N Y . I encourage everyone to read the TWO major books about Corning glass. One is called GENERATIONS and the other is called INNOVATIONS. I highly recommend these two books to anyone interested in the history of Corning glass.

    I also grew up in Port Allegany (1966 to 1984) and I think its time Port started entertaining offers from other manufacturing companies to replace the PC. If Corning and Pittsburgh Plate Glass can’t find it to stick with us, then we will find someone else. Good reddens to PC. We loved them deeply since 1927 but they didn’t love us back so time to replace what we lost. Perhaps TESLA or some other tech innovation company who needs parts. Port has a lot going for it. Route 6, an established rail road, tons of natural gas, lots of fresh water….whats the hold up!? So rich in natural resources and great location…..why on earth isn’t this town looking for a replacement for the PC? I have my suspicions why, but not appropriate to share in this venue. Sad very very sad.

  • Parag – if you have the same thickness of glass blocks – you’ll likely be able to use the accessories – although Seves has a couple of different installation systems. I would first recommend you check the thickness of the blocks you have and how it lines up with the thickness your installation accessory system was designed around. Mike

  • Hi Mike. Thanks for sharing the details about the sad demise of PC Glass Blocks. Now I understand why I am unable to find installation materials for these. I am adding a wall in my basement and am trying to match the glass block windows in other areas of the basement. I have 6x6x4 blocks that I want to install. Do you know if the installation materials for Seves available at Home Depot can be used for PC? The rough opening dimensions for PC and Seves are same and so I hope the channels, spacers and sealant can be used.

  • Chip – we may have some Seascapes block and if we don’t our team has some resources I believe on where we can find some for you. Feel free to call us at 877-668-5888. It is sad about Pittsburgh Corning, but as a dealer of their’s for many years they didn’t listen to their customers and were arrogant because they felt they ‘controlled’ so much of the market. It is sad – but in the end it’s the customer’s who rule whether our businesses exist or not. Mike

  • Great Article / Sad Topic.
    I am looking for 8 x 8 Seascapes pattern to replace fogged up ones. I need two but would buy more if I find them.


  • Give our office a call – we may have enough – but if we don’t have enough for you I’ve got a few buddies in the industry across the country who will likely be able to accomodate you. Call us at 877-668-5888. Mike

  • Don if you mean 4″ thick glass block finished ends we still have 40 in stock as I looked right now. You can call 877-668-5888 – Mike

  • Steve – we do have (or can get) the Pittsburgh Corning 90 degree angle blocks (they called them a Hedron and also an end block. Now Pittsburgh Corning only made those blocks in a 4″ thickness so the thin line units you have will not be compatible with them. Feel free to call me for more insight. Mike – 877-668-5888.

  • Hello. I have about 80 of the Pittsburgh Corning 8″ Decora Thinline glass blocks and I am in need of (10) Veer 90 degree blocks, (23) End Blocks and (1) Double End block. Would you have any of these that you would sell or know of a source where I may find them? I know they are discontinued. I’m trying to finish a small project. Thank you.

  • Christopher – you are right on with your statement. In the case of Pittsburgh Corning I think they could have treated customers better and listened to them more often – that would have helped. You can still get the made-in-America blocks. We have some and some distributor friends of mine have some as well. If we can help you with this let me know. Mike

  • Universal Truth, applicable to all species and organizations, to which there has never been an exception in all of time: Failure to adapt to a changing environment will result in extinction.

    Dang irksome. I’m glad I thought to buy extra glass blocks years ago for my lighted exterior driveway circle, but bummed that our planned shower wall will not have the same Made-In-America blocks….

  • Who can I contact about the craft glass blocks that Pittsburgh Corning would supply the AC Moore craft stores on our area near Allentown,PA. AC Moore is replacing them with another block that has a rectangular top on them and they do not stay in the block – the Pittsburgh blocks were nicer because the cap snapped on and there was a rubber cap for the plug to come thru for lights. I would buy them by the cases when I went in. Can u tell me if u continued to make these blocks and how can I get more of the directly…thank you

  • Toni – I would recommend to look at the box and see if there is any packaging on it. If they are not in an original box you could measure them (they should be 11 3/4″ x 11 3/4″ x 3 7/8″ )and/or also send us a picture of them and we can take a look. Mike

  • I just bought six 12x12x4 blocks from a 75-year-old local, independent hardware store that’s closing its doors. Is there a way to determine whether they are, indeed, PC blocks, and their approximate age? Thank you…

  • Don – yes the other manufacturers do you have similar products (not exactly the same – but we can accomplish the same styles of walls and windows). You can feel free to reach out to us for help with your project by calling 877-668-5888.

  • Mike, I am surprised to hear this straight out of the horse’s mouth, when I called direct to PC. My question is these other manufactures, to they carry or manufacture same line of products like the Tridron, Hedron, or the End Block and corners? If so where are my points of contact?

  • Bonjour j’espère au vous allez m’aider. J’ai des bloc de verres 12×12 et je ne trouve pas de cannelure ni de bande assez large. Ça me prendrait une cannelure de 4po et des bandes de 3/Pô. Merci de me répondre

  • Ed – thanks for your nice comments. It was sad to see things unfold at Pittsburgh Corning. I am looking forward to the advancements being made by Seves and giving the glass block industry a new “shot in the arm.”

  • Hi Mike – I grew up in Port Allegany & worked at the PC glass plant for 2 summers. Thank you for this article and for your perspective,

Leave a Reply

Your email address will not be published. Required fields are marked *