Don’t Let Windows Become a Weak Point for Your Rain Penetration Systems

Window Rainscreen

Regardless of which rain penetration systems are used, windows and doors must be drained. Most failures to control rainwater occur at windows. Some windows come with drainage pans or tracks which are part of their design. These alone are not enough to stop rainwater penetration. Most leaks occur between the window frame and the window opening. Therefore, a reliable window flashing system and proper drainage is necessary to prevent problems down the road.

Screen Shot 2014-12-22 at 2.45.44 PM


Sub-sill flashing is the best way to prevent rain penetration. It works on all four corners of an opening. Buildings perform best when a drainage gap is provided behind the cladding which can safely drain away the water from window subsill areas.

Window and Door Drainage is Critical

Dörken is a leading manufacturer of air and moisture membranes for commercial and residential construction sold under the DELTA® brand name. Dörken is known for delivering innovative premium quality products to the construction market. We back up our high performance DELTA® products with educational programs and full technical support.  To learn more about our air and moisture barriers, visit our website.