With glass fibers embedded in durable resins, fiberglass grows and shrinks very little with weather changes. Fiberglass can be painted any color at your house or you can select various factory-finished combinations of indoor and outdoor colors. Several manufacturers add insulation inside the cavities of vinyl and fiberglass doors to improve comfort and lower utility bills. This insulation is foamed in place to eliminate energy-wasting voids. Natural wood sliding glass doors are most attractive and can offer a wider range of profiles and finishes, but they require more maintenance.
Wood is also susceptible to damage and swelling from moisture.
Exterior aluminum and vinyl-cladding eliminates much of the maintenance. If the threshold seal is aluminum, make sure that it is thermally broken between indoors and outdoors. Marvin uses an insulating Ultrex sill material that is very strong and durable. This is important with a high traffic patio door. Instant Download or Rush Mail Order Update Bulletin No.