Replacing your windows, all panes at a time


By CCHRC Staff

The “Ask a Builder” series is dedicated to answering questions Fairbanks residents have about building, energy and the many other parts of home life.

Q: What is the relationship between boilers and combustion air?

Any appliance that expels air must have its own air supply or one appliance could be drawing air through another. When a boiler expels gas out its flue, an equal amount of make-up air must be brought in. Similarly, any appliance that sends air out of the house needs to be supplied with intake air. If an appliance is not supplied with intake air, it may pull the air it needs down through the boiler’s chimney, thus “backdrafting” the boiler and pushing combustion gasses into your home.

For example, in a “tight” home (one with sound insulation and well-sealed doors and windows), where a wood stove and a boiler both draw air, the boiler may get its air supply by backdrafting the wood stove. However, if you have provided adequate air supplies for both appliances, both should operate with no problems.

Q: If one of the panes in my double or triplepane window breaks, can I get the pane replaced, or do I need to replace the whole window?

When one of the panes in a double or triple pane window breaks, all of the glass layers must be removed and replaced.

Taking apart a window also involves removing several parts such as the “stop” which holds the glass in place, the jamb liner, and other components.

Typically the frame and any associated trim can remain untouched. Virtually all factory- built vinyl, fiberglass, and wood windows have provisions for removing the glass.

If the window can open, simply disconnect the opening portion from the frame and take it to a glass shop.

Repairing a “fixed” or “picture” window can be more complicated. Wood windows may use screws and be relatively easy to replace, however removing the glass from vinyl or fiberglass units is less obvious. In many cases, this involves a “snap in” type window stop located either on the inside or the outside of the window, separate from the main portion of the frame.

Generally, this type of repair is best left to professionals, since removing the stops can be difficult and can result in more broken glass.

Sometimes the window stop will be adhered to the frame with two-sided glazing tape or adhesive caulking.

The replacement glass not only needs to be the proper length and width, but also the proper thickness and space between the panes. If a glass shop replaces the glass, they will provide a guarantee, which in itself is worth piece of mind.

Alaska HomeWise articles promote home awareness for the Cold Climate Housing Research Center (CCHRC). If you have a question, e-mail us at can also call the CCHRC at (907) 457-3454.