Glass Block Basement Windows — Davenport, Iowa

On this Davenport, Iowa project, our crew replaced four aging basement windows with new mortar-set glass block windows — a low-maintenance upgrade that tightens up the basement against drafts and moisture while adding security and natural light.

What we did

The home had four older basement windows that had reached the end of their service life. We removed all four, then installed new glass block windows set in mortar. Each opening was sealed to help protect against air and water intrusion, and we left the basement cleaner and more secure than we found it.

Glass block is set in mortar rather than hung in a frame, so once it cures it becomes a solid, fixed part of the wall. That is part of what makes it low-maintenance: there are no moving sashes to warp, no wood to rot, and no steel frame to rust.

What homeowners should know about old basement windows

Basement windows are easy to overlook until they start causing problems. Older steel- and wood-framed basement windows often loosen, rust, or rot over the years, and as they do, the seal around them tends to break down. That can let in drafts, allow water to seep in during heavy rain, and create a weak point for security.

Glass block is one common answer to those issues. Because it is mortar-set and solid, it typically seals the opening more tightly than an aging framed window, while still letting in natural light and adding privacy. In many cases it also holds up better over time, since there is very little on a glass block window to fail.

One thing worth keeping in mind: glass block is a fixed window and does not open. Where a basement bedroom needs a code-compliant escape opening, an egress window system is the right tool instead. For a utility basement, laundry room, or storage area, though, glass block is often a durable, low-upkeep way to close off a drafty or leaking window for good.

Photo highlights

The photos show the finished glass block windows set into the foundation, the new block being placed, and one of the original openings after the old window was removed. The interior view shows how much natural light the glass block still lets through.