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Comment by wharvle | Hacker News Reader

We got some. I'd been skeptical that screwing with your roof that much was a good idea, but so many people do it and seem happy about it... it must be OK?

TL;DR never again. Way too expensive for what it gains you, way too much risk (to your roof, of future costs for roof maintenance, et c.) Installing on a roof is crazy-expensive compared to ground. If we have enough room at our next house I'll self-install panels at ground level and have an electrician do the rest. It's just not favorable enough a move, otherwise, to be worth the risk and hassle. Ground-level's way cheaper, even if you don't self-install parts of it, and won't make your roof more complicated. It's technically saving us a little money, but no, not worth it, the peace of mind is worth the tens of dollars a month or whatever.

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Last summer we put new panels over sunny side of our 20yo terracota roof. Since the roof is just overlaid "bricks", we only had to remove some of those, use screws to fix hooks to underlying structural wood, and put the roof tiles back on. On the hooks we install metal wireframe, into which the panels were seated and fixed.

Apart from raising the panels to the roof and fixing them in place (brother helped), we did it just me and dad. Panels are just too heavy/bulky for 2 people.

The terracota roof have 0 new openings, as the hooks are in the space where two tiles overlay, so there is 0 fear of long term damage trough water ingress. The hooks and aluminum wireframe fixture were the most expensive part of roof instalation.

So, cheap, fast (3 weekends total?), and fun. I am surprised some people have totally different experience

House roofs in the US are often quite steep, and typically asphalt shingles over plywood. Terra cotta exists but is rare outside certain regions (and not that common even in those). Wood shingles exist but most are terrible, most still around now were installed after we ran out of wood good enough to give them their supposed 50+ year lifespan (we ran out in the 70s or 80s), so people tend to replace them with asphalt when they go to shit in 20-30ish years rather than paying a large premium to replace them with more (bad) wood. Slate, copper, et c., exist, but are basically "exotic"—no normal person has those on their house unless they bought a very old house in a bad neighborhood (a house with a roof like that's likely to be crazy-expensive if it's not in a bad neighborhood).

Most people in the US don't work on their own roofs. You need safety equipment most people don't own, plus protective equipment to keep from damaging the shingles, and to be proficient with it you need to use the stuff more than once every couple decades. And even then, it's pretty dangerous.

We have a lot of rooftop solar in Australia, and I’ve never heard any arguments regarding risk the roof or roof related maintenance costs.

Can you provide any more details regarding your scenario? Is it a specific style of roof? Or material?

And what are the significant costs regarding roof vs non-roof installation?

In our situation the only suitable place to put panels was on the roof, so it wasn’t an option. But I’m keen to understand the factors.

1) The time it takes for the panels to recoup their costs is already long.

2) Now the panels have to be removed and re-installed any time those parts of the roof are worked on. That's expensive. Roofing companies tend not to like solar. You'll have trouble getting a warranty on the work if you've got solar, and likely pay a premium for a company that'll provide one (on top of the much higher labor costs) by finding a company that does both solar and roofing.

3) If work ever needs to be done on the panels, and it doesn't fall under a warranty, it'll be more expensive than ground-level.

4) There's a greater chance of something going wrong with all the above because solar adds more components to the whole system of the roof, aside from punching a bunch of holes in it.

The higher costs and risks plus naturally long pay-off period mean I don't plan to ever pay for rooftop solar again. Wish I hadn't this time.

What risks and complications do you worry about with a roof install? Unless you are maliciously incompetent as an installer there is no risk of destroying anything. And while it's easier to access and service on the ground, the roof is often perfectly tilted towards the sun AND lets you have many square meters of panel without sacrificing any area you could use for anything else.

Future maintenance now has to involve removing the panels, then installing them again afterward. That's a lot of extra work (so, money). Lots of roofers hate solar and won't touch it (they've worked on many roofs solar installers fucked up—talk to some). So now you need two companies involved. You'll have to take great care with the whole arrangement if you want the usual warranty you get with roof work from any decent roofing company (again, many hate solar and will be reluctant to guarantee work that has solar touching it, especially if another company has to do that part, which is often the case). The coordination effort means roofing projects are longer now.

It's just not worth it once you factor in the period to recoup investment on the panels. The extra headache and risk plus long period before you're in the black anyway, just nowhere near being worth it. And all that assumes nothing goes wrong with the panels

Yeah I mean a roof has a lifespan of 20-40 years, and a solar installation also has a lifespan. I certainly wouldn't install solar on a roof that I expect need any service/replacement within the coming 10 or 15 years at least. On the contrary, when a roof does need a replacement, that's when I'd perhaps consider installing solar too.

If I thought I'd live more than 10 or 15 years in my house (Which I'm probably not) then I'd be investing right away. But I have already lived 10 years in it, will do max 10 more years, and the roof is also 10-15 more years since the house is 25. That makes it a non-starter for me. I'd do it if I were in the black in 5 years though. Or if I had more than one power outage lasting more than one hour a year. Luckily I don't.

> Unless you are maliciously incompetent as an installer there is no risk of destroying anything.

It's actually quite easy to accidentally create a leak with various common roof systems. It's often quite easy to fix the mistake when it's made. But the mistake is not always noticed, and the work is not always done by competent and experienced people. There doesn't need to be anything malicious about it. Part of my day job is fixing those mistakes.

yeah, in an ideal world I'd rather use spare backyard space for this rather than grass.

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