RAU-FIPRO Vs. uPVC Window Profiles
August 8, 2026
Why we chose RAU-FIPRO
When it comes to window and door materials, there are several options available on the market, including PVC (commonly referred to as vinyl or uPVC), aluminum, wood, and fiberglass. Each material offers unique advantages and drawbacks, and each has its place in the industry. As with every component that goes into our products, we took a careful and deliberate approach when selecting our window and door profile system. We met with manufacturers, attended industry trade shows, tested a wide range of products, and conducted extensive research. After evaluating countless options, we ultimately chose to manufacture our windows and doors using the RAU-FIPRO® profile from REHAU.
Understanding the Limitations of uPVC
uPVC has long been one of the most popular materials used by window and door manufacturers. It offers an attractive, smooth finish, excellent resistance to weathering, and relatively straightforward manufacturing processes. However, despite its many benefits, uPVC has limitations when it comes to structural strength and stability. These limitations become increasingly apparent as window and door sizes grow larger. One of the primary challenges is thermal expansion and contraction. uPVC expands and contracts at a significantly higher rate than many other building materials (.08mm per degree Calvin per meter). In regions with extreme temperature swings, this movement can result in dimensional changes of one inch per 10-feet of material.
To compensate for this movement, manufacturers insert steel reinforcement into the uPVC profile. The steel is attached using screws that connect the reinforcement to the profile. While this approach improves rigidity, it does not eliminate the fundamental issue: the steel and uPVC expand and contract at different rates. Over time, the repeated stress placed on the fastening points can cause the screw holes in the uPVC to elongate, creating a keyhole slot and reducing the effectiveness of the reinforcement. As this process continues, the steel becomes little more than added weight, while the profile gradually loses structural stability. Eventually, the window or door may no longer perform or seal as effectively as it did when it was first installed.
The RAU-FIPRO Advantage
One of the features that ultimately tipped the scales in favor of RAU-FIPRO for us is its significantly improved dimensional stability. RAU-FIPRO profiles expand and contract up to 60% less than traditional uPVC profiles. After making the switch, we observed a noticeable reduction in service calls related to temperature-related movement. Because our manufacturing facility is located in Manitoba, where products are exposed to some of the most dramatic seasonal temperature fluctuations in North America, we understand the importance of designing windows and doors that perform reliably in any climate. Our goal has always been to build products that stand the test of time, regardless of where our customers live. Choosing RAU-FIPRO allows us to deliver products that remain stable, durable, and high-performing throughout decades of seasonal change.
Strength Inspired by Aerospace and Automotive Engineering
The core of RAU-FIPRO is a high-performance fiber-reinforced composite material similar to those used in the automotive and aerospace industries. The result is a profile that is stronger, more rigid, and more dimensionally stable than many traditional window and door materials. RAU-FIPRO combines advanced fiberglass-reinforced technology with a durable outer layer of uPVC. Unlike traditional fiberglass products, where fibers are aligned in a single direction, the glass fibers within RAU-FIPRO are distributed throughout the material, providing strength in multiple directions. Another key advantage is weldability. Traditional fiberglass profiles cannot typically be welded because they are made using thermoset resins. RAU-FIPRO, however, utilizes a thermoplastic material, allowing corners and joints to be welded in a manner similar to uPVC. This creates stronger, more durable connections and contributes to a longer-lasting finished product.
The Best of Fiberglass and uPVC
Traditional fiberglass windows often require painted finishes to protect them from weather exposure and ultraviolet radiation. While effective, painted surfaces can fade, chalk, or deteriorate over time, particularly when exposed to years of direct sunlight. REHAU addressed this challenge by incorporating an outer layer of uPVC over the RAU-FIPRO core. This protective layer shields the profile from the elements while providing a smooth, high-definition finish that is both attractive and easy to maintain. The result is a material that combines the structural strength and durability associated with fiberglass with the refined appearance and low-maintenance benefits of uPVC. Rather than forcing homeowners to choose between the strengths and weaknesses of two different materials, RAU-FIPRO brings the best qualities of both together in a single profile system.
Building on a Strong Foundation
When we chose a material for our windows and doors, we weren’t simply selecting a component. We were choosing the foundation on which to build our company and our reputation. We wanted a material that would allow us to create products that consistently exceed expectations, deliver long-term performance, and stand up to the harshest conditions. We believe RAU-FIPRO provides that foundation. It gives us the confidence to continue innovating, improving, and pushing the boundaries of what high-performance windows and doors can achieve, while ensuring our customers receive products designed to perform beautifully for years to come.
If you have questions about our products or manufacturing process, we’d be happy to help. Contact us today to learn more or request a quote for your new windows and doors.