Click to download a complete comparison of Fibrex® to vinyl and to Marvin’s Ultrex®, the fiberglass frame material used in their Integrity Windows.
You will see that the Fibrex material indeed is twice the modulus strength of vinyl but has a lower tensile strength. More importantly, you will see that Fibrex® and vinyl are inferior to full fiberglass frames featured in Marvin’s Integrity Windows. This, the superiority of the exterior finish, and the option for full wood interiors are why we proudly represent Integrity Windows.
Now for the fun part. Who is the very nice person who can so generously offer 20% off and no interest for 5 years? I am not interested in Fibrex® windows, but I would love to replace our bank line of credit with “no interest” money!