Save Your Windows
While Keeping Your Original Wood Frames

Wood Window Restoration and Renovation

Most Frequently Asked Questions about Wood Windows

Why should I try to save my wood windows?

One of the main reasons most homeowners chose their home in the first place was the way the house looks and the windows are an important aspect of that character appeal. Windows can add a very distinctive and enhancing aspect to a house. The older the home the more important the ascetics concerning size, placement, and muntins. In fact, the things that most people don't like about their windows are that they are difficult to operate, drafty, rattle, and single pane, thereby requiring the unsightly triple track storm window. They love the looks but hate how they perform. Bi-Glass System® keeps those wonderful ascetics and upgrade the energy efficiency of the windows at a lower price than new wood windows. We can truly Save Your Old Wood Windows!

Back to frequently asked questions

Why is wood better than vinyl for windows?

About half the residential replacement windows sold in the US are made of vinyl. At first glance, vinyl seems to make sense. Manufacturers are justified in their claims that it insulates well and never needs painting. But vinyl isn't nearly as rigid as other window materials such as wood and fiberglass. Worse, vinyl begins to soften and distort at 165 degrees Fahrenheit, a temperature that is easily reached in the space between a window and drape on a sunny day. Although all window materials expand and contract as temperatures rise and fall, vinyl moves more than twice as much as aluminum, wood and fiberglass. Vinyl expands seven times farther than glass with each degree. That action can pop seals between the frame and the glass. Last year Environmental Building News, a newsletter for contractors and architects, evaluated all framing options used in windows and advised readers to avoid 100 percent vinyl window frames because of their durability problems.

Anderson Corporation, the worlds largest manufacturer of windows, has never made an all vinyl window for sale in the US. "Vinyl simply is not suitable for use on its own as a window material," says Mike Compeau, a spokesman for the company. Vinyl windows have been on the market for only 15 to 20 years. According the Hakim Elmahdy, the chief window expert for the Canadian government's Institute for Research in Construction, "There is not enough data or track record for these windows to say, yes they will last for 50 years."

Noted Architect Robert A.M.Stern says," We won't spec a house with vinyl windows. We won't even use a vinyl-over-wood window. We only use windows that are framed in wood. And we paint them or stain them. We don't leave a natural finish. The paint seals the windows."

Back to frequently asked questions

Do historical societies approve of the Bi-Glass System®?

Historical preservation groups around the country are welcoming the Bi-Glass System® with open arms. In New England, in both New Hampshire and Vermont, Historical Preservation groups are specifying Bi-Glass® as the renovation/restoration system of choice. Although there are preservation groups in some areas that are so restrictive that any upgrading is taboo, most groups welcome the diversity of options available from using hidden balances and weather-stripping to completely changing out the single pane glass to insulated units. Most historical societies are concerned that the exterior of historical properties remain the same. The Bi-Glass System® maintains that look and still upgrades the window to higher energy efficiency standards.

Back to frequently asked questions

Will my windows be more energy efficient after Bi-Glass®?

Windows are comprised of three basic components . Each has a direct impact on the energy efficiency of the window.

  1. Jambliner and weather-stripping system: This accounts for 50% of the heat loss in an old window and is usually a weight and pulley system that has no weather-stripping on either the horizontal or vertical surfaces. By installing a new compressible vinyl jambliner with silicone bulb weather-stripping at the horizontal joints we virtually eliminate any infiltration at these points.

  2. Weight pockets: This area accounts for 30% of the heat loss in an old window. The cavities in the jamb that are used to house the weights are virtual wind tunnels that funnel air into the house. By filling these pocket with insulation we stop the movement of air and eliminate infiltration at these areas.

  3. Glass: This aspect of the window is responsible for 25% of the heat loss in a single glazed window. By replacing the single glazing with insulated Low E glass we increase the R Value by 3 times thus eliminating the convection currents that occur with single glazing. This increases the energy efficiency and the comfort factor for anyone sitting near a window. No more drafts!

Back to frequently asked questions

Will my windows tilt in?

Yes! By installing vinyl tilt jambliners in place of your old weights and pulleys, you can tilt you windows in for easy cleaning and remove them for simple maintenance.

Back to frequently asked questions

Is this an expensive process?

The Bi-Glass System® is a licensed system. There is no standardization of prices between licensees. However on the average our system is from 10% to 60% less expensive than comparable wood SDL (simulated divide lights) products manufactured by quality wood window providers. The best way to get a price is to contact your regional installer and ask for a quote specific to your windows.

Back to frequently asked questions

Are new wood windows "better" than my old ones?

New wood windows are manufactured using the current fast growth pine. While relatively stable as a building material this fast growth wood has a major drawback. It has a tendency to rot more quickly than older growth southern yellow pine or longleaf pine, the wood with which older windows were commonly made. The growth rings on fast growth pine are over twice as wide as the slower growth wood. The soft (wide) section of the growth ring (summer growth) is more susceptible to rot than the hard (narrow) section (winter growth) which is more impervious to the elements. The wider the rings the more potential for degradation of the wood. Southern yellow pine is relatively rare now and not used for window manufacture. It is rich in pitch which inhibits rot and has very tight growth rings. Older wood is far superior to newer fast growth wood for longevity. This is why we encourage homeowners to save their existing sash by updating with the Bi-Glass System. Most older windows are in the 50 to 100 year old range and in very good condition. Treated correctly they can last at least 50 more year!

Back to frequently asked questions

If vinyl jambliners aren't appropriate are there other options?

If your house is governed by a historical group that refuses to allow the use of vinyl jambliners , we can offer other systems that allow the upgrading of glass, weather-stripping and locks while maintaining the look of the old jamb and sash. We offer three options.

  1. First we can resize the existing weights to compensate for the increased weight of the insulated glass. The downside is that option doesn't allow the weight pockets to be filled with insulation.

  2. Option two is to install spring balances which are cut into the sash and stay hidden from view.

  3. Option three is to install a tape balance which is a system that can handle any weight and is installed into the same hole the old pulleys occupied. These hook to the windows with a flat steel tape.

  4. Option two and three offer the ability to insulate the weight pockets and eliminate that infiltration. All these options require additional weather-stripping on the stiles (vertical sections of sash) with vinyl corner bead and felt stripping. While these options offer a definite improvement for old windows the optimum weather-stripping system is vinyl jambliners.

Back to frequently asked questions


What is Bi-Glass | Technical Details | Gallery | Questions | Contact Us
Request Information | Become a Bi-Glass Dealer | We're Famous | Site Map | Home

Bi-Glass Systems
Call 1-800-729-0742 for a Dealer in Your Are