A Basic Introduction to Glass and Best Practices of Glazing

Glass is a remarkable material with a rich history, dating back to natural formations from volcanic activity and lightning strikes. Unlike metals, glass doesn’t fit neatly into the archaeological periods of Stone, Bronze, or Iron Ages. Natural glass has existed as long as the Earth itself.

Different Types of Glass

1. Annealed Plate Glass (Sheet Glass)

Annealed glass is widely used in homes for windows but is generally not suitable for storm doors, patio doors, and shower enclosures due to safety concerns. Annealed glass, also known as float glass, is made through a process pioneered by Pilkington, where molten glass is floated on a bed of molten tin to produce a uniform thickness and smooth surfaces.

Applications and Restrictions:

• Residential Use: Common in windows but restricted in areas like door side lites, patio doors, and bathroom windows near shower enclosures.

• Regulations: Not allowed for windows in pathways or below 24 inches from the walking surface. Recent ANSI and ISO recommendations require any glass over 9 square feet to be safety glass.

Stress and Durability:

• Stress Cracks: Plate glass can develop stress cracks due to uneven surface temperature caused by partial shading or exposure to UV and infrared light.

• Dynamic Fatigue: Despite stress, glass returns to its original state once the stress is removed, showing resilience over years of wind exposure.

2. Tempered Glass

Tempered glass is significantly stronger than annealed glass due to its unique manufacturing process, which involves heating the glass to make it flexible and then rapidly chilling it. This process creates compression on the outer surfaces and tension in the core, making it up to five times stronger than annealed glass of the same thickness.

Safety Features:

• Breakage Pattern: When tempered glass breaks, it shatters into small, dull pieces, reducing the risk of injury.

• Applications: Commonly used in high-rise buildings, commercial applications, household items like cell phones, pyrex dishes, passenger car windows, and bathroom windows.

3. Laminated Glass

Laminated glass consists of two layers of glass with a polyvinyl butyral (PVB) interlayer. This construction ensures that even if the glass breaks, the fragments remain bonded to the interlayer, providing safety and structural integrity.

Benefits:

• Security: Harder to break, offers protection against forced entry, and can be manufactured to be bullet or bomb-proof.

• Sound Abatement: Absorbs sound due to the PVB interlayer, reducing noise.

• Weather Protection: Ideal for regions prone to hurricanes, tornadoes, and high winds. It keeps the glass intact and prevents debris from penetrating living spaces.

• UV Protection: Blocks 95% of UV light, protecting interiors from harmful rays.

Applications:

• Storefronts and Entrances: Provides security and durability.

• Overhead Glazing: Required by building codes for skylights, sunspaces, and sloped glazing installations to prevent injuries from falling glass.

• Jewelry Vitrines: Offers clear visibility and protection.

Best Practices of Glazing

1. Proper Installation:

• EPDM Setting Blocks: Use these to absorb building movement and ensure the glass is not in direct contact with masonry or metal, preventing stress cracks.

• Correct Measurements: Ensure precise measurements to avoid uneven weight distribution, which can lead to breakage.

2. Safety Precautions:

• Lead Paint: When working with old windows, be cautious of lead-based paint. Use safety masks and goggles to prevent inhalation of harmful particles.

• Team Coordination: Large glass installations require teamwork and precise coordination to handle the weight and ensure safety.

3. Regular Maintenance:

• Inspection: Regularly inspect glass installations for signs of stress or damage, especially in high-traffic areas or where safety glass is required.

Conclusion

Understanding the different types of glass and their applications helps in making informed decisions for both residential and commercial glazing. Whether it's the classic annealed glass, the robust tempered glass, or the secure laminated glass, each type has its unique benefits and uses. By following best practices in glazing, you ensure safety, durability, and optimal performance of your glass installations.

For expert glass services, contact Dedicated Glass Works at 973-947-6381 or get a free quote online. Let us help you choose and install the best glass solutions for your needs.