Advanced design and engineering solve an old problem The expansive appeal of inswing patio doors is easy to understand. What’s been more challenging to figure out was how to keep rainwater out during heavy rain. Inswing patio doors do away with the slightly raised, grooved tracks used by most sliding patio doors. Instead, they typically feature lower-profile sills that are great for offering a smooth transition between indoor and outdoor spaces but aren’t as good at keeping water out when heavy rain pelts the doors. Minimizing water entry is a long-standing challenge with traditional sill design. Creating deep sill channels to handle rainwater increases sill height and creates a tripping hazard. Mechanical weep covers help, but are a magnet for debris, pet hair, insects, and dirt—often requiring maintenance or repair after a few years. JELD-WEN’s Klamath Falls, Oregon–based Research and Development team used the latest  advanced engineering and design technology to solve this vexing problem.   Advanced technology advantage “The inswing door is a particular challenge because you have a lot more water on the weather stripping,” says Jacob…