I. Basic Definition
Q: What is a window header trim?
A: Also known as a window header trim, it is a horizontal decorative line above the window. It is a component of the exterior window casing, with a drip groove/eaves, which serves both waterproof and decorative functions.
Q: What is the difference between window casing trim and windowsill trim?
A: Window header trim (top): Window top, with drip, guides water and prevents leakage.
Window casing trim (side): Sides of the window, for edge decoration, covering gaps.
Windowsill trim (bottom): Bottom of the window, sloped outwards for drainage.

II. Material and Specifications
Q: What is our material?
A: EPS: High cost-effectiveness, rich in styles.
Q: Regular dimensions?
A: Width: 12–20cm
Thickness: 8–15cm
Length: Customized, extending 15–30cm beyond the window width on both ends
Can also be customized in various sizes.
III. Functional Role
Q: What is the core function?
A: 1. Waterproof and impermeable: The drip groove cuts off the water flow, preventing rainwater from seeping into the window frame periphery.
2. Decorative beautification: Enhance the three-dimensional effect of the window, improve the architectural grade, and adapt to European / New Chinese styles.
3. Protect the wall: Cover the gap between the window frame and the wall, preventing paint cracking and efflorescence caused by sun and rain.
IV. Installation and Construction
Q: Installation key points?
A: 1. Base layer: The wall should be flat and solid, without hollowing or cracks.
2. Fixing: Fix with expansion bolts + adhesive mortar, leave 3–5mm gap between joints, seal with weather-resistant sealant.
3. Drip: The drip groove faces downwards, and is cut off 2–3cm from the window edge to ensure vertical water dripping.
4. Slope: Outward slope **≥5%**, to prevent water accumulation and backflow.
Q: Service life?
A: EPS: 8–15 years
V. Purchase and Design
Q: Purchase considerations?
A: The profile has a clear drip groove, and the structure is integrated without seams. The color is coordinated with the exterior wall, and can be customized to simulate stone / real stone paint effects.
Q: Design and matching suggestions?
A: 1. European style: Choose curved / richly detailed styles, paired with window casing trim of the same style.
2. New Chinese style: Choose simple straight lines + a small amount of carving, with a more stable color tone.
3. Modern minimalist: Choose narrow flat style, same color as the wall or slightly different.