That’s a good point about green roofs needing more attention than people think. I’ve seen a lot of DIY jobs where folks skipped proper drainage or waterproofing, and it never ends well—water finds every weak spot. Even with regular shingles, if you don’t get the overlap right, you’re basically inviting leaks. I always tell people: water runs downhill, but it’ll take any shortcut it can get. Overlapping like fish scales isn’t just tradition, it’s survival for your roof. If you’re thinking about adding layers (plants or otherwise), don’t skimp on the prep work underneath... that’s where most problems start.
Couldn’t agree more about the prep work. I’ve seen people get excited about the “green” part and totally overlook what’s underneath. Waterproofing and drainage aren’t optional—if you skip them, you’re just asking for headaches later. Good call pointing that out.
Waterproofing and drainage aren’t optional—if you skip them, you’re just asking for headaches later.
Couldn’t agree more. I learned that the hard way after a “quick” DIY job on my shed roof. Looked great at first, but I skimped on the underlayment and paid for it when the first big rain hit—water everywhere. The fish scale layering is clever, but if what’s underneath isn’t solid, it won’t matter much. Prep takes extra time, but it’s worth every minute.
Fish scale layering is honestly pretty cool—makes you wonder if fish ever get leaks... Anyway, I totally get the temptation to skip steps when you’re in a hurry (or it’s 90 degrees and you’re sliding around like a penguin up there), but man, that underlayment is like the unsung hero. I’ve only helped on a handful of roofs so far, but every time someone tries to save time or cash by cutting out waterproofing, it bites them later. My uncle thought tar paper was “overkill” on his garage roof—fast-forward a year and he’s got moss, water stains, and something growing in the rafters that probably has its own zip code.
One thing I’m still figuring out is how much overlap is really enough. On the job sites, some folks swear by six inches, others say four. I’ve even seen one guy double up at the valleys “just in case.” Is there such a thing as too much overlap? At what point are you just wasting shingles and adding weight?
Also, those starter strips… I used to think they were just marketing fluff until I saw what happens when you skip ‘em—wind gets right under there and rips the first row off like it’s peeling a sticker. Not fun to fix after the fact.
Curious if anyone here has tried those synthetic underlayments instead of old-school felt. Are they really worth the extra bucks? They feel lighter but not sure about long-term durability. And for anyone in rainy climates—do you go extra with ice & water shield or just stick to code minimums? Where I’m at, we get sideways rain half the year and “code minimum” seems optimistic.
Anyway, fish scales got it figured out for a reason. Wish my first roof did...
Man, you nailed it with the underlayment being the unsung hero. I’ve seen more “mystery leaks” traced back to someone getting lazy with that step than I can count. As for overlap, I’ve always gone with six inches—maybe overkill, but after seeing a neighbor’s roof peel up like a sardine can during a windstorm, I’ll take the extra weight. Synthetic underlayment is slick (literally and figuratively)—way lighter, and it doesn’t turn into mush if you get a freak rain mid-job. Only downside I’ve noticed is it can get slippery when it’s hot, so watch your step. And yeah, in places where rain comes at you sideways, code minimums feel like a dare... I always double up on valleys and edges. Learned that one the hard way after a hailstorm turned my “good enough” job into a water feature.
