That filter fabric gunk is no joke—seen it myself, especially under big maples. Here’s what I’ve learned: first, always check those drain outlets every couple months, not just in the fall. If you can, add a gravel guard or even a simple mesh cap over the drains; it won’t stop everything but slows the clogging. And honestly, don’t trust that “maintenance-free” pitch for any green roof... nature always finds a way to pile stuff up. Still, when you stay on top of it, they do look awesome—just takes more work than folks expect.
don’t trust that “maintenance-free” pitch for any green roof... nature always finds a way to pile stuff up.
That’s been my experience too, especially with coatings that claim to “seal out debris.” Some of those actually make things worse by trapping moisture under the gunk, and then you get mold or even rot. I’ve noticed on a couple jobs that the wrong coating can make filter fabric clog faster, since it changes how water drains off the roof. It’s weird—sometimes the simple setups with regular checks work out better than all the fancy add-ons.
