Micro-mesh has its limits for sure, but honestly, I've never had much trouble with sedum mats attracting insects or critters. Had mine for about four years now, and aside from the occasional curious bird poking around, it's been pretty uneventful. I think the key is keeping it healthy—if the sedum starts dying or thinning out, that's when you might see pests moving in.
That said, I do think sedum mats can sometimes hold moisture longer than you'd want, especially after heavy rains. I've seen a few roofs where the moisture buildup under the mats caused issues with the underlying membrane. Personally, I'd rather deal with a bit of pollen sludge in my gutters than risk moisture damage underneath a green roof setup. Regular checks are definitely important either way, but I'd suggest anyone considering sedum mats to think carefully about drainage and moisture control before jumping in.
Good points about moisture buildup—I've wondered about that myself. Do you think the type of underlying membrane makes a big difference? I've heard EPDM membranes handle moisture better than some others, but I'm not totally sure if that's true or just marketing hype.
Also curious if anyone's tried adding extra drainage layers beneath their sedum mats. I saw a video where someone used a thin gravel layer underneath to help with drainage, but wouldn't that add a lot of extra weight? Seems like you'd need to be careful about structural limits.
I've been considering sedum mats for a while now, but the moisture issue keeps giving me pause. Regular roof checks definitely seem smart either way...but how often do you guys actually climb up there and inspect everything closely? Once a season, or more frequently after heavy storms?
"Regular roof checks definitely seem smart either way...but how often do you guys actually climb up there and inspect everything closely?"
I usually try to get up there at least twice a year—spring and fall. After a heavy storm, I'll do a quick visual check from the ground, but climbing up every time feels excessive (and honestly, a bit risky). As for drainage layers, I looked into gravel too, but the weight worried me. Ended up using a lightweight drainage mat instead. So far, moisture buildup hasn't been an issue.
Twice a year sounds about right to me too, though I admit sometimes it's just once if things get busy. Climbing up after every storm is definitely overkill—plus, the ladder gets sketchy real quick when it's wet. Good call on the drainage mat instead of gravel; gravel can be a pain if you ever need repairs underneath. Have you noticed any difference in insulation or heat retention since switching to the mat? Curious how it compares...
I've been using drainage mats for about two years now, and honestly, I haven't noticed any major difference in insulation or heat retention compared to gravel. Technically speaking, the mat shouldn't really affect insulation much anyway—its main purpose is just to keep things dry and allow water to drain efficiently. If you're noticing insulation differences, it's probably due more to other factors like attic ventilation or insulation material itself rather than the drainage mat.
I will say though, from a maintenance standpoint, the mats are a dream compared to gravel. Had gravel on my previous roof and every time I had to get up there for repairs or inspections, it was such a hassle. Gravel shifts around, gets messy, and you inevitably end up losing some down the gutters or onto the lawn (which your mower will later find... ask me how I know).
Agree with you completely on ladder safety too—climbing up after every storm is unnecessary and borderline dangerous, especially if you're dealing with wet leaves or moss buildup. Twice a year seems sufficient unless you've got specific issues like heavy tree coverage or known roof weaknesses. I usually do a quick visual check from the ground after storms just to make sure nothing obvious happened (branches down, shingles missing), but that's about it.
As far as saving money goes, regular inspections definitely help catch small issues before they become big headaches. Last year, I spotted some flashing starting to lift around my chimney during my routine checkup—caught it early enough that it was just a quick DIY fix instead of a full-blown leak repair job inside the attic ceiling. So yeah, regular checks are worth the effort.
One minor downside I've found with the mats is that they can get slippery if algae starts growing on them (especially in shaded areas). It's manageable with occasional cleaning, but something to be aware of if you're frequently up there doing maintenance.
Overall though, drainage mat was definitely an upgrade over gravel for convenience alone. Heat retention-wise... probably not going to notice any meaningful change either way unless your roof insulation itself has issues.
