According to guidelines, how should windows be flashed when manufacturer instructions are absent?

When manufacturer instructions are not available for flashing windows, the best practice is to use a comprehensive approach that incorporates various types of flashing to ensure maximum protection against water infiltration. This includes header flashing, jam flashing, and pan flashing combined with a water-resistant barrier.

Header flashing is installed at the top of the window to direct water away from the window. Jam flashing is positioned on the sides of the window, ensuring that any water that may enter is redirected outside rather than behind the wall assembly. Pan flashing is placed at the bottom to catch any water that might leak through the window, directing it to the exterior. The addition of a water-resistant barrier further enhances the waterproofing system, helping to prevent moisture from penetrating the wall.

Using this multi-faceted method creates a more robust defense against water intrusion compared to using a single type of flashing or inadequate materials. This is essential for maintaining the integrity and durability of the building envelope, emphasizing the importance of following best practices, especially in the absence of specific manufacturer directives.