Installation of Arched Windows: Types and Technical Insights
Arched windows elevate your home’s character — and their installation requires unmatched skill and experience.
Understanding the Types of Arched Windows
Several distinct types are common in U.S. homes. Arch top windows combine a rectangular base with a curved top, and can be factory-mulled or installed in two parts. A single unit reduces joints and leak risks, but is heavier and more expensive, requiring a precisely tailored rough opening.
Option 1: Full Arched Window Unit
Installation begins with measuring the entire curved opening. Headers must be reinforced due to added weight. Shimming and leveling come first, followed by fastening the window around all sides. Arched tops may use flexible brackets or custom flange tabs.
Option 2: Split Installation (Window + Transom)
The opening is split into a rectangle for the main window and an arch for the transom. A spacing gap allows for expansion. The base window is installed first, flashed on all sides, and its top flashing tucked beneath the arched unit’s bottom edge.
Installation Essentials: Materials and Tools
We rely on industry-trusted tools and products: Tyvek FlexWrap, Protecto Wrap, or Zip Tape; OSI Quad Max and DAP Dynaflex Ultra sealants; Hilti CF812 or Great Stuff Pro foam; flexible trim; and 3.5” galvanized screws or Andersen-approved fasteners. Laser levels and arch templates ensure accurate placement.
Common Pitfalls and Why Expertise Matters
Precision and product choice are key. Avoiding rigid materials, positioning fasteners correctly, and using curved flashing properly make all the difference in long-term performance and visual quality.
Conclusion: Excellence in Every Curve
Arched windows are stunning, but complex. We install each one with reinforced framing, advanced flashing methods, and finish materials that match the curvature — ensuring form and function for decades to come.
