O:K, all you vinyl salesmen, you asked for it; First of all, let me say that I do use vinyl windows from time to time, and I’ll be the first to admit they have their place. But to suggest that they’re ALWAYS the best choice for EVERYBODY, and that they’ll work just as good as fiberglass in any situation, is just not facing reality. I’ve added coments in parantheses and shown deletions with …. Dots. If you want to read the whole articles just go to the sites I’ve listed. Here’s what a quick 10 minute surf through the internet turned up; and believe me, it’s the tip of the iceburg:
• “The life expectancy of a fiberglass window exceeds all other traditional materials.
• Vinyl..................15 years
• Aluminum............20 years
• Wood................25 years
• Fiberglass...........40 years”
“Fiberglass expands and contracts at similar rate as glass (1/7th rate of vinyl)”
Source: http://www.progressivefiberglass.com/in ... #EXPANSION
• “ (Fiberglass) has Less torsion and stress between glass and frame in cold weather (than vinyl, and also…)
o Reduced air leakage
o Decreased stress on locking mechanisms”
“Since vinyl has a higher coefficient of expansion than either wood or aluminum, vinyl window frame profiles should be designed and assembled to eliminate excessive movement caused by thermal cycles. … Large hollow chambers within the (vinyl) frame can allow unwanted heat transfer through convection currents.
fiberglass frames are dimensionally stable and achieve good insulating value … and can be filled with insulation for higher thermal performance. The strength of fiberglass allows manufacturers to maintain the same sight lines as aluminum windows while achieving significantly lower U-factors. The low coefficient of thermal expansion maintains seal integrity and minimizes warpage or leakage in high inside/outside temperature differentials. Fiberglass pultrusions have a higher heat deflection temperature than vinyl, permitting the use of dark colors unlike other thermoplastic extrusions. They can be painted, powder coated, or finished with coextruded acrylic resin.”
SOURCE: http://www.commercialwindows.umn.edu/ma ... blies1.php
“Pultruded fiberglass is virtually impervious to moisture (it has a moisture migration rate of 0.17 percent)
Stability over temperature extremes
(Fiberglass) Pultrusion, like glass, has a very low coefficient of thermal expansion/contraction (3.8 x 106 in/in oF). It does not distort in the extreme hot or cold temperatures to which window frames are subjected. Window frames of (fiberglass) pultrusion hold their original shape, are impervious to temperature changes, and maintain their initial air infiltration rates” SOURCE:
Fiberglass has been around for a long time... it has an excellent record for durability. Fiberglass is strong, so hollow parts can be made without the stiffeners required for vinyl. This allows manufacturers to produce higher efficiency windows by filling voids with insulation. In fact, insulated fiberglass windows are even more energy efficient than those made from solid wood. You can paint fiberglass windows, but they won't deteriorate if the finish wears away. ( ON THE OTHER HAND) : Vinyl windows are inexpensive… They often look chunkier than wood or metal windows because vinyl isn't strong enough …. . The other problem is that the texture is unmistakably plastic. You can't paint them… Vinyl Windows: Then and Now: Early vinyl windows had problems with thermal expansion. When temperatures changed, the vinyl sash would expand or contract at a very different rate from the glass. As a result, the window fit poorly, leaked, or cracked. Such problems have been on the decline, but… SOURCE: http://www.bobvila.com/HowTo_Library/Ma ... A1843.html
. The truth is that currently the projects I’m working on use vinyl about 30% of the time; Clad wood probably 25%, Fiberglass about 35%, and Aluminum about 10%. But as fiberglass is coming down to earth on cost, it is increasingly becoming the choice of more and more people. And I really don’t see that changing. But who knows, mabey you know something I don’t. That’s why I give my clients a whole lot of information and let them make their own decisions. I get paid the same flat fee no mater WHAT kind of window goes on the project. As long as they’re still a good reference in 15 years; I’m happy.