Discover the wonders of Glass Block Windows!


The classic pattern providing normal privacy needs.


Providing privacy with more style.


Maximum privacy and adds medium light.

Glass Block windows are an attractive and eye-catching alternative to plate glass windows. With their variety of patterns, sizes and textures, Master Seal glass block products adapt to your needs in any room.

Master Seal Glass Blocks are very popular for basements for added security and water tightness. They also allow 80% of available light to transmit in both directions. Options available are fresh air vents with screens, and special dryer vent blocks to allow you to vent your dryer out through the window.

Energy Efficient

Lower energy cost with glass block windows that have double the thermal resistance (R-value) of traditional single-glaze plate glass. There will be no energy-wasting drafts as you complete your solid wall while allowing 35% more light into your basement.

Security & Durability

These Glass Block wonders are the greatest windows for resisting potential intruders, they can be made to resist Tornadoes, Fire, Hurricanes, Earthquakes and even a bullet from a .357 magnum handgun!

Maintenance Free

Glass Block windows are virtually maintenance free and resist scratches and graffiti. Glass Block windows never need to be painted or sealed!


Glass Blocks are a beautiful alternative to plate glass or a vinyl window with security bars option while being less expensive, more energy efficient, and allowing more light into a dark basement. A pleasing effect of Glass Blocks is they constantly transform and manipulate color and light.

Glass Block windows are the perfect choice for basement security. Do away with those metal bars, stop paying your alarm company and install Glass Block basement windows.

Get the unsurpassed strength and security of a Master Seal glass block window.

Master Seal uses only type S mortar for added security and strength.  Type S mortar is specially formulated for glass block installations because of its superior adherence.

Benefits of glass block:

  • Resistant to burglars
  • Brightens up the room
  • Choose from several decorative patterns
  • No maintenance
  • Superior insulating qualities for lower heating and cooling costs
  • Allow light in while maintaining your privacy

Choose from three distinct patterns of glass blocks. Each fulfilling a specific need for privacy, light transmission, and style.