Rooftop Solar Panels

So, do the solar panel salesmen (or installers) have small-print disclaimers that they’re not responsible for structural damage nor roof integrity? For example, do they offer an analysis of your roof with solar panels plus a snow load? I wonder how many rooftops are just waiting to go if most roofs cannot take more than two layers of shingles. …just saying!

First, where do you live? I assume the US? I don’t know your laws, or the certification and education required for “solar salesmen”.

Here in Germany, solar “salesmen” usually work together with plumbers if it’s about solar thermic. Some plumbers do an extra-course and get certified as solar experts. There are also solar clubs who help with the different aspects.

What do you mean that a roof can’t support more than two layers of shingles?? Why would anybody need two layers? If the roof is leaking, you fix the leak, you don’t put another layer of shingles on!

Any house built to German standards, esp. in the South where heavy snowfall is expected, will need enough structural integrity to bear a certain load. This is all in the documentation of the house plans. A lot of PV modules are of course integrated when building a new family house, so the roof can be already built sturdier, and easy access can be integrated into the roof.

When PV modules are installed onto older roofs, there will be an inspection through a statican, as with every other measure that impacts the stability of a house! (Well, I don’t know how the regulations in the US are - maybe you can just knock down a wall when renovating without checking it’s a structural support?) This will be done partly from the plans, partly with measurments.

When for example a solar fund wants to cover a commercial building or warehouse, that often have not proper shingles roof like houses, but a tin roof, it’s often necessary to put in additional support for the weight.

How much of that process is prescribed by regulations or available from qualfied and certified experts in the US, I can’t say. Best bet would be to contact a solar club or enviromental club to point you neutrally to experts.

Well, in the part of the US I live in, we are allowed by building code to add a second layer of shingles over the first as a repair measure. I always thought that if you were going to go to the effort of climbing up with all the bales of shingles, you might as ell just replace the damned roof properly. A ‘reshingle’ tends to last about 5 years, a proper roof replacement lasts about 20.

And while one is supposed to get permits to restructure the inside of your house, most people just go ahead and do it. Frequently to disasterous results, if you actually watch some of the home renovation shows where they go in to a newly purchased house and renovate it properly - they uncover some of the most horrible amateur work. We are going to be knocking out a wall that was put in by the previous owner that is nonstructural, but we actually know it is nonstructural [and really crappily done at that.]

Most people do homw renovations without blueprints in hand, most people dont actually have the blueprints to their homes. Oddly enough, I happen to have a set of original blueprints to the house my great grandfather built … I suppose I could get it built somewhere as a custom home, but I would have to get an amish or mennonite carpentry crew in to do the post and beam frame for it. If I could even get the proper lumber for it now.:dubious::frowning:

In the US, when it comes time to replace the shingles on the roof, it’s fairly common to just install a new layer on top of the old one. This saves the effort & cost of tearing off the old layer.

But that can only be done once (or at most twice), because modern houses are often not built strong enough to carry more layers on the roof. Older houses were built stronger, and can often hold more – my 101-year-old house had 3 layers of shingles on its roof, with the bottom one being heavy wood shakes. All of those were removed when the roof was redone.

wow. Just … wow. You mean there is no law regulating how to things properly, or that people just ignore them? Does nobody know/realize the many problems that can arise from doing it cheap instead of right, or does nobody care?

I wonder: is this connected to the different housing culture between Germany and Europe? Here, houses (and ground) are expensive. The traditional method is: Joe gets a job at 20 and gets a house building savings contract (Bausparvertrag) After 7 years of saving, and state bonus, he makes a down payment of 10% and gets a cheap special loan to build/ buy the house. He lives in this house and raises his children while paying off the loan. After 30 years, when he’s around 60 = close to retirement, his house is paid off and he can live rent-free in his old age (or sell and move back to the city).
Therefore it’s in Joes interest to keep the house in good order. Making an investment in the house that pays off in 10 or 20 years is worthwhile because he will live in it at least as long. Resale value of the house is secondary.

In the US, it seems that people only look at the resale value, and sell houses after 4-10 years, and therefore don’t care about how good things are done; and if an investment takes longer than 5 years to pay off, it’s “not worth it/ too expensive”. Is that right?

It depends on why you are replacing the shingles in the first place - are a lot of them broken/ destroyed by storm, or is the roof leaking? If the latter, then you need to find the leakage. It can be something as simple as accumulated dirt in the connections between the shingles preventing close fit and letting rainwater in.

Also, how does that work practically - where do the shingles hook onto if you lay them on top of the old ones? When you lay shingles the first times, they latch onto the grid of green beams. Where do they latch onto when you put them on top of old shingles? Or are we talking about different kinds of shingles?

If you put one layer on top of the old one, how can you be sure there aren’t pockets of damp due to the uneveness of the new layer?

Do you not have any official places that supervise buildings and approve them? Or does everybody ignore the lack of permits because nobody controls them? Does everybody overestimate their ability or underestimate the necessity of experts (plumbers, electricicans, staticans) in American culture?

In the States, remember that everything is handled at a state level (like fifty different countries) or even at the local level.
For example, California has different regulations from New Jersey. The former probably has extensive earthquake requirements, while the latter probably has more requirements required for northeastern winters.

There is no “building code police” that will knock on your door and go through your house looking for five-year-old home-brew violations.

Bad home improvement work is typically caught by the inspector when you sell your home.
In order to transfer title of the house, you must obtain a “certificate of occupancy,” which often requires a building inspector to come through your home.

When we bought our home, the inspector found a few electrical issues (20A breaker on a 15A circuit; missing bridge wire across the water meter), which the former owner fixed up.

In addition, the buyer is strongly recommended to have an engineer inspect the home prior to buying. This is often required by financial institutions. Any really shoddy work should surface between the town inspection and the engineer.

Aside from the time-of-sale inspection, any serious work that generates visible evidence outside of the house will likely raise the suspicion of the town building inspectors, and you will probably get a knock on your door. For example, if you have old appliances sitting out for the trash collector, you might be asked about the permits.

In general, an American homeowner has the right to do their own work without needing to be a licensed plumber/electrician/whatever. That doesn’t mean that they do it correctly or take out the proper permits. Permits are often expensive. When I had my roof redone last year, the permit cost $350.

It’s quite easy to hop on down to Home Depot and buy a bunch of building supplies and do the work yourself if you know how. And it is quite tempting to attempt this even if you don’t know how.

All contractors must be licensed and must have building permits. And the permit will likely say “work must be inspected prior to final payment to contractor”

In much of the US, if you aren’t within actual city limits, and as long as it’s not an addition to the house, or a major renovation, it’s a case of “You own the building, go ahead and ruin it with any shoddy do-it-yourself work your incompetence is capable of.” Permits and inspections are only required in my town if you are putting on an addition, or redoing all the wiring or plumbing. No permit would be required for a kitchen remodeling or a roofing job. Cross the line into the city 3 miles away, however, and any work that can easily be seen being done from the outside will require a permit.

Well, the most relevant law is that of private property ownership – it’s my house, and here in America I can do what I want to it, without government bureaucrats interfering.

And why do you think this is not the right way to do it? Roofers have been doing it this way for decades, and houses are not falling down. Are you an expert on roofing?
Why would 2 layers of protection not be a good thing? I frequently wear 2 or more layers of clothing when it is cold or stormy outside.

I’ve no idea of how it works practically – I hire an expert roofer who does know. I count on him knowing how to do it, and he must, because he guarantees his work for several years.

But that picture doesn’t look like shingles as used here – it looks more like a tiled roof. And I’m not sure what you mean by a grid of green beams. My bare roof was a slanted surface of flat plywood, then they covered it with paper or plastic from a roll, and attached asphalt shingles laid over that. Quite different from that picture.

constanze is an expert on everything related to how America sucks.

What we usually think of in the US when you say roofing shingles. Tile shingles are never applied one on top of another. Asphalt shingles are quite often applied ontop of another layer.

Several places around here were roofing contractors who went into solar installation. As I understand it if they installed it, it included a warranty for roof issues related to the install. If your roof was in bad shape already they would include a bid for redoing the roof, or at least the area in question.