In the construction industry, the roof is the most vulnerable point for water penetration. For architects and contractors, installing aluminum roof windows or aluminum skylight windows requires more than just a structural fit; it requires a comprehensive understanding of water management and flashing integration. A poorly installed unit can lead to expensive internal damage, mold growth, and compromised insulation.
At Bunniemen, with 17 years of experience as a professional ODM manufacturer, we design our roof systems to be as impenetrable as they are functional. Our production workshop utilizes CNC drilling and automated cutting to ensure every unit leaves the factory with millimeter precision. However, the final performance depends on proper installation. Here is our professional guide on how to install our systems to ensure a leak-free, long-term result.
Structural Preparation and Opening Precision
The foundation of a leak-proof installation begins before the window even arrives at the site. Because our aluminum roof windows are manufactured with a high-strength 1.8mm-thick thermal break profile, they require a perfectly squared structural opening.
Determine the opening size: Ensure that the pre-reserved opening in the roof rafters is several tens of millimeters wider than the window frame. This reserved space can be used for insulation filling and final leveling adjustments.
Checking for Square: Use a laser level or a framing square to verify the opening. If the rafters are out of alignment, the frame of the aluminum skylight windows may twist during installation, which can compromise the automotive-grade EPDM seals and lead to air or water leaks.
Integrating the Underlayment and Flashing
Water management on a roof relies on the principle of “shingling”—where the upper layer always overlaps the lower layer. This is critical when installing aluminum roof windows.
The Underlayment Collar
Before securing the window, an underlayment collar should be integrated around the frame. This secondary barrier ensures that any water that manages to get past the primary roofing material (tiles or shingles) is directed away from the window opening. At Bunniemen, we recommend using a high-quality breathable membrane that can be taped directly to our 1.8mm aluminum profiles, creating a seamless transition.
Flashing Kits
The flashing is the most important component for preventing leaks. As specialized roof window manufacturers, we emphasize that the flashing must match the specific roofing material—whether it is corrugated metal, flat tiles, or slate.
Bottom Flashing: Should overlap the roofing material below the window.
Side Channels: Must be tucked under the roofing material on the sides to catch runoff.
Top Flashing: Must be tucked under the roofing material above the window to ensure water flows over the unit rather than under it.
Securing the 1.8mm Thermal Break Frame
Once the opening is prepared and the underlayment is in place, the window must be mechanically secured. Our 65 series features a reinforced 1.8mm profile that provides the “dead-load” strength needed for overhead installations.
Fastening Points: Use the pre-drilled holes provided by our CNC drilling system. Using the factory-specified points ensures that the fasteners do not interfere with the thermal break or the internal drainage channels of the window.
Leveling: Use shims to ensure the window is perfectly level and plumb. Even a slight tilt can cause water to “pool” in the corner of the frame rather than following the intended drainage path, which can eventually degrade the EPDM seals.
Sealing the Glazing: 5-12A-5 Double Tempered Glass
In aluminum skylight windows, the seal between the glass and the frame is a frequent point of failure in lower-quality products. We mitigate this through superior material selection.
We utilize 5-12A-5 double tempered glass held in place by high-compression EPDM gaskets.
The 12mm Argon Gap: This space not only provides thermal insulation but also ensures the glass remains stable under pressure.
EPDM Integrity: Unlike standard silicone which can peel away over time, our automotive-grade EPDM strips are UV-resistant and maintain their “memory,” keeping the glass tightly sealed against the frame even as the building shifts or undergoes thermal cycling.
Ensuring Proper Drainage and Ventilation
A leak-free installation is also a well-ventilated one. Improperly installed roof windows can suffer from internal condensation, which is often mistaken for a leak.
The Ventilation Revolution: Our roof windows are designed to facilitate airflow. When installing, ensure that the internal vapor barrier of the house is tightly sealed to the window frame. This prevents warm, moist interior air from reaching the cold aluminum frame, where it could condense and drip.
Drainage Holes: Ensure that the external drainage holes in the aluminum profile are not obstructed by roofing debris or sealant. These holes are essential for allowing any moisture that enters the frame’s tracks to escape safely to the exterior.
Why Choose Bunniemen for Your Project?
As an ODM with a 3,500 m² workshop, we understand that B2B partners—wholesalers, builders, and architects—need a product that is easy to install correctly.
Manufacturing Precision: Our automated cutting machines ensure that every frame is perfectly squared, reducing the struggle of on-site leveling.
Welded Corners: Every aluminum roof window we produce features welded corners, which act as a final “fail-safe” against leaks. Even if the exterior flashing were to fail, the welded frame itself remains watertight.
Global Expertise: Having exported to North America and Australia for 17 years, our designs have been proven to withstand diverse and extreme weather conditions, meeting AS2047, WERS, NAMI, and NFRC standards.
Conclusion: A System Designed for the Elements
Properly installing aluminum roof windows is a technical process that rewards attention to detail. By focusing on structural squareness, proper flashing integration, and the use of high-performance materials like 1.8mm thermal break profiles and EPDM seals, you ensure a leak-free installation that will last for decades.
At Bunniemen, we are proud to provide the engineering foundation for these high-performance installations. From the precision of our CNC drilling to the safety of our 5-12A-5 double tempered glass, we deliver the quality that professional installers trust.
