this post was submitted on 02 Jun 2026
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[–] SupraMario@lemmy.world -4 points 1 day ago (4 children)

Do you think that they build roofs that can't support people walking on them?

[–] paranoia@feddit.dk 19 points 1 day ago* (last edited 1 day ago) (2 children)

Yeah, I do, and I have good reason to, because I am a structural engineer and have designed them myself on occasion. A lot of these canopies over car and bike shelters are just a sheet of plexiglass.

[–] atomicbocks@sh.itjust.works 3 points 1 day ago (1 children)

Where are you designing these that they don’t need to support hundreds of pounds of snow or rain, or stand up to hail?

[–] paranoia@feddit.dk 8 points 1 day ago* (last edited 1 day ago) (1 children)

Northern/Western Europe.

Hail bounces off, rain flows off. For a very light duty structure like a smoking shelter, bike shelter or trolley corral, they sometimes have a curved plexiglass roof that snow can just fall off or be blown off. A person is a much more intense load than snow (a person's whole weight can be on one foot). The frame might take it, but the cladding may not.

Usually they are just a product off the shelf.

[–] atomicbocks@sh.itjust.works 0 points 1 day ago (2 children)

My parents just bought and installed a small off the shelf carport, it has its own built-in gutter system and the ability to hold 100s of pounds on its metal roof. Nobody is covering cars with plexiglass, that would literally defeat the purpose of having shade.

[–] Malyca@lemmy.zip 4 points 22 hours ago (1 children)

I've seen the plexiglass ones he was talking about

[–] atomicbocks@sh.itjust.works 0 points 22 hours ago

I’m not doubting they exist, it sure looks cool. I’m just doubting it would stand up to a couple years where I’m from, and I don’t think that you would even need to stand on that to install solar panels anyway.

[–] paranoia@feddit.dk 6 points 1 day ago* (last edited 1 day ago) (1 children)

Here's one for sale in Denmark, where I am, and where it snows. Polycarbonate instead of PMMA. Same thing. I wouldn't stand on it.

https://dancovershop.dk/products/carport-arizona-2-89x4-95m-palram-canopia-gra

Get an opaque sheeting if you want to keep UV off. Point stands.

[–] atomicbocks@sh.itjust.works -2 points 1 day ago

... that thing wouldn’t protect your car from shit where I’m from… that wouldn’t even protect your car from the sun except at like noon.

[–] SupraMario@lemmy.world 1 points 1 day ago (1 children)

Which are a canopies or awnings not a roof.

[–] paranoia@feddit.dk 4 points 1 day ago (1 children)

Fuck off lmao. A canopy is a roof.

[–] SupraMario@lemmy.world 2 points 22 hours ago

No it's not, if you asked to have a roof installed and someone installed a fucking canopy over your house, you'd be pissed.

This is like asking for a truck and they show up with a station wagon and tell you well it's got foldable back seats.

Words have meaning.

[–] ColeSloth@discuss.tchncs.de 5 points 1 day ago (1 children)

They don't build parking shade roofs to support the weight of being covered in panels, though. That has to be planned for. A typical panel that's around five and a half foot by a bit less than 3 and a half foot weighs around forty pounds. Having like two of those on your covered spot at your house would probably hold fine. But to a large parking area will add a huge amount of weight.

[–] SupraMario@lemmy.world 1 points 22 hours ago

Shade canopies or awnings...but yea solar is heavy.

[–] grue@lemmy.world 8 points 1 day ago (1 children)

Yes, when they're called "awnings."

[–] SupraMario@lemmy.world -1 points 1 day ago

Which isn't really a roof, it's just a cover.

[–] Alcoholicorn@mander.xyz 5 points 1 day ago* (last edited 1 day ago) (1 children)

Yes. It doesn't need to be 1 contiguous roof, gaps big enough to fit a ladder are ideal.

spoiler

[–] SupraMario@lemmy.world 0 points 1 day ago (1 children)

That's more of an awning than a roof though. Plus that picture shows that this was specifically designed with the panels. As those are just straight solar panels and not roofing that's had solar installed to it.

[–] Alcoholicorn@mander.xyz 4 points 22 hours ago* (last edited 22 hours ago) (1 children)

Awnings are fabric lol. This is a roof made with solar panels, a solar roof.

[–] SupraMario@lemmy.world -1 points 22 hours ago (1 children)

And those panels are not light weight...so someone could walk on them if they wanted.

[–] Alcoholicorn@mander.xyz 3 points 9 hours ago

Do not walk on solar panels.