That’s a good question about the structural side of things. I’ve worked on a handful of green roof installs around the Midwest, and honestly, the weight is usually the first thing people worry about—especially with older homes. Sedum systems are on the lighter end compared to some other setups, but when you factor in saturated soil after a big rain, it can be a lot more than folks expect. Sometimes it’s not just about the age of the house, but how it was built in the first place. Some older rafters are beefier than what you see today, but others are undersized for anything extra.
Had one project where we brought in an engineer to check out a 1920s bungalow before putting up even a thin green roof. Ended up needing extra bracing in the attic—wasn’t a huge job, but definitely not something you’d want to skip. On newer builds or garages, sometimes you get lucky and they’re already overbuilt. But yeah, that up-front work (and cost) can be a dealbreaker for some people.
I’m curious—did your neighbor have to do any reinforcement? And do they have any issues with drainage or leaks? I’ve seen some green roofs handle storms like champs, but others get weird ponding if the slope isn’t quite right.
Also, for anyone else reading—has anyone tried those modular tray systems? Wondering if they make things easier for retrofits or if it’s just more marketing hype...
Interesting point on the modular trays. I’ve looked at a few of those systems for a flat garage roof, but honestly, I’m not convinced they’re as “plug and play” as the marketing suggests. The weight’s still there, and if your structure can’t handle it, trays won’t magically fix that. I do like that you can swap out sections if there’s a problem, though—seems less disruptive than tearing up a whole built-in system.
On drainage, I’ve seen more issues with older homes where the slope isn’t quite right or gutters are undersized. My neighbor tried a green roof on his 1950s ranch and ended up with some minor leaks after a big storm last year—turns out the membrane wasn’t lapped properly at one edge. He caught it early, but it was a pain to fix.
Curious if anyone’s had luck retrofitting these systems onto low-slope roofs in hurricane-prone areas? I keep hearing mixed things about wind uplift and edge detailing when storms hit hard.
I hear you on the modular trays—definitely not a magic fix for weight. When I put in a green roof on my carport (low slope, coastal Florida), the biggest headache was making sure the edges were triple-sealed and anchored. Hurricane season had me sweating, but so far, no blow-offs or leaks. I’d say, if you’re retrofitting, double-check your edge details and maybe overdo the fasteners. It’s not glamorous, but it beats chasing trays down the street after a storm...
I get the urge to overdo fasteners, but honestly, I’ve seen roofs where too many penetrations just led to more leak points down the line. Sometimes less is more, especially with older structures. Edge details matter, but chasing perfection can backfire...
I get what you’re saying about overdoing it. I helped a buddy re-roof his shed last summer, and we thought more nails would mean more secure shingles. Turns out, three months later, he had little leaks right where we’d gone heavy with the fasteners. Live and learn, I guess. For those who’ve ridden out storms—did anyone actually see less damage on roofs with fewer penetrations? Or is it just luck of the draw sometimes?
