Frequently Asked Questions
About half the residential replacement windows sold in the U.S. 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, 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% vinyl window frames because of their durability problems.
Andersen Corporation™, the world's largest manufacturer of windows, has never made an all-vinyl window for sale in the U.S. "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."
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, weatherstripping, and locks, while maintaining the look of the old jamb and sash. We offer three options.
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. Option two is to install spring balances, which are cut into the sash and stay hidden from view. 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. Option two and three offer the ability to insulate the weight pockets and eliminate that infiltration. All of these options require additional weatherstripping 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 weatherstripping system is vinyl jambliners.