Fiberglass windows and doors resist swelling, rotting and warping. The frame expands and contracts at approximately the same rate as the insulated glass it holds for improved energy efficiency and strength. While fiberglass frames do not require repainting for upkeep, the material is able to be repainted if you prefer to change colors.
Milgard’s fiberglass is produced using a process called pultrusion. Glass rovings and mats are pulled at tremendous forces through a resin bath and a series of dies. These materials combine and catalyze to provide tensile and torsion strength. All final products undergo extensive testing for quality and consistency.