Exterior window trim is the finishing touch on windows. Traditionally, windows were constructed of wood or aluminum. Wood, while a good insulator, requires regular scraping and painting to maintain a pristine appearance. Over time, exterior windows made of aluminum pits and stains, and expands and contracts with change in temperature. A good conductor, aluminum window frames are cold in the winter and hot in the summer. The shortcomings of these two materials helped propel the success of vinyl exterior windows and trim. Vinyl (PVC) windows are constructed with spacers that act as insulators so the frames conduct neither heat nor cold. Additionally, vinyl windows can be cleaned with a mild soap and sponge—they never need paining and they will not pit or stain.
Prompted by the low maintenance of vinyl windows, homeowners began to inquire about the virtues of using PVC instead of wood or aluminum exterior window trim. PVC lineals are used to trim windows.
Homeowners who want low-maintenance, durable building products accelerated the trend to PVC exterior window trim. Unlike wood trim, which can absorb water or become infested with termites, PVC trim is durable and stands up to the weather extremely well. And, in addition to PVC lineals, PVC profiles—crown moulding, sills, and rosettes—can be added to customize the exterior of the home.
Architectural windows are another application for cellular PVC exterior window trim. The unique characteristics of cellular PVC trim allow it to be heated and shaped into a variety of shapes, allowing profiles that can be used to trim virtually any window shape or create custom designs for any exterior application.
Convection air circulating ovens, heating blankets and radiant heaters have all been used successfully to heat bend cellular PVC trim. Generally, millwork shops or extrusion manufacturers create specialty profiles, and it is not recommended that installers attempt to create architectural profiles on site.
For more information please visit CertainTeed’s trim products page.