About Glass Blocks

Glass block is a fascinating building material that looks both fragile and sturdy. It can create a barrier yet allow light to penetrate. Glass is a versatile combination of silica, soda and lime cooked together to form a liquid that is then formed into glass block. The attraction for glass block is not only its strength but also its immediate eye appeal. It never needs to be painted or sealed. It is beautiful on its own or in combination with other materials in architectural design.

History

Using glass has been common for centuries. Remember the glass beads of the Egyptians and the ships with the pyramid-shaped glass skylights built into their decks. Artisans made individual blocks of glass that required a lot of effort, making them too expensive for common use. The history of glass blocks as a building material starts in the 1900's with the advent of the glass-manufacturing machine by Loeme in 1903. A French architect, by the name of Joachim designed and built the first dome made with a combination of the newly-invented, machine-made concrete and glass block. Three years later, Freidrich Keppler applied for a patent on glass block of 4 to 6.5 cm in thickness.
Hollow glass blocks were designed also at this time and were better liked by builders for their sound proofing and thermal qualities. The Corning-Steuben block was the design that really worked well and its design is still in use today. It was fashioned by fusing two molded glass halves with a hollow interior together under high heat.

Significance

Building with glass block was an exciting advancement for architects as they now had a new kind of building block with which to play. They were already aware of the versatility of glass; how they could add color and texture without losing any of its character; how they could mold it and shape it into various forms. Now it was available them at a reasonable cost to offer as an attractive alternative to the normal building materials. Builders could use the glass as it was resistant to chemicals. Glass as a building material was an intriguing alternative to brick made of clay or concrete and offered the benefit of burglar resistant windows.

Function

Designers and architects love working with glass block for several reasons. It allows light into a space. It reduces and insulates against sound. It has a thermal rating of 60 to 90 minutes depending on the thickness. It is not bothered by the elements and can easily be cleaned. It can be either transparent or opaque depending on the customer's desires. Glass block is available in different colors and patterns for visual interest. Designers love using it in bathroom and kitchen architecture. Commercial architects use it in offices as space dividers as well as in window applications. Even homeowners can use it in their own construction and remodeling projects in a variety of creative ways.

Size

Glass block comes in a variety of sizes. The standard size is the 8x8x4 inch block. Variations of the 3 and 4-inch block include 6x6, 12x12, 6x8. Each of these sizes are actually undersized by 1/4-inch to allow space for mortar in the construction process.

Considerations

Researching the different companies that offer glass block will also alert you to the fact that there are acrylic substitutes being manufactured. Unfortunately, they do not offer the same high level of quality as found in the glass block and are still about the same cost. There may be situations where the acrylic block might be advantageous since it is a much lighter product as in construction problems with weight loads on floors and walls.

Resources

• What is Glass?
• History of Glass Blocks