roof (shingle) mount, confused, recommendations?

[pookguy88]

so I've got most the solar system planned out in my head, the only thing that I can't seem to wrap my head around is how to mount the panels to my shingled roof.

I understand there's single mounts but you need to hit the rafter beams when you use those, does that mean something like this (https://signaturesolar.com/asphalt-mini-rail-w-flashing-roof-mount-for-panel-6in-black/) would need the panels to line up exactly where the rafters are?

So would I need a system that includes one long rail?

Any help or advice would be greatly appreciated, I don't see many videos on Youtube about actually installing these types of mounts.

Thanks!

 

[cdherman]

Typically you are going to run two rails, parallel horizontally across your shingle roof. They will be say 40" apart for a 60" panel, ballpark. Different panels have different specs as to where they want the rail, depending on things like wind and snow loads.

Now those rails need to be secured to your roof. That "mini rail" you link to is not what gets used typically. Signature probably has them, but sometimes their website is a touch wonky. Things get placed it the wrong place in other words.

You need what is referred to as a "flashed post".

Picture of railing with flashing post.

Now, that post and flashing needs to be over a rafter indeed. Depending on the construction of the roof (strength of the rafter) and the characteristics of the rail, you may be able to get by with say every 48' or 64" between posts. (some new construction has rafters on 24" center, so other numbers would apply) Or in more obscure settings, much more with heavier rails. My solar panels are on a pole barn with massive trusses every 9'. I went with really heavy duty Iron Ridge rails, and my posts are every 9'.

There are lots of flashing systems out there. Lots of rails. Lots of stuff. Looks like pookguy joined in 2021 but waited till today to post. So welcome. I am a newcomer around here, but installed my first solar system in 2009.

 

[Solar Guppy]

so I've got most the solar system planned out in my head, the only thing that I can't seem to wrap my head around is how to mount the panels to my shingled roof.

I understand there's single mounts but you need to hit the rafter beams when you use those, does that mean something like this (https://signaturesolar.com/asphalt-mini-rail-w-flashing-roof-mount-for-panel-6in-black/) would need the panels to line up exactly where the rafters are?

So would I need a system that includes one long rail?

Any help or advice would be greatly appreciated, I don't see many videos on Youtube about actually installing these types of mounts.

Thanks!

Look at IronRidge

 

[RV10flyer]

If there is anyway to ground mount your pv array, you will be safer, easier to build, get the correct angle/azimuth, troubleshoot, repair, clean and remove snow. Have fun.

 

[cdherman]

If there is anyway to ground mount your pv array, you will be safer, easier to build, get the correct angle/azimuth, troubleshoot, repair, clean and remove snow. Have fun.

Not to misdirect the original question, but I kind of disagree. There are a lot of roofs that are close enough. Then the panels are out of the way, no need to mow around them, no kids to throw rocks at them. But if your asphalt shingles are at year 20 of a 25 year design life, you better replace your roof first.

The OP wants advice about how to mount panels to a shingled roof. Agree with other post that going to IronRidge website would be good choice too. Suspect they have better explanations that I. IronRidge is good stuff, IMO......

 

[pookguy88]

Thanks for all the replies, @cdherman , that really helped and what I suspected, those mini rails seemed pretty narrow use case. I think I need to get full rails.

And yeah, I’ll check out the iron ridge site, I see they have a calculator for all that too.

 

[zanydroid]

For a DIY install it's smart to make your life as easy as possible. All the mini products need more precision. Having the old school 12 or 18" wide flashing gives you more room to recover from a mess up vs zero flashing or 6" wide flashing. Also some of those reduced flashing products cost more

IronRidge is pricier but it is stronger and has a longer span/cantilever distance than say Unirac SM light. Which also facilitates first time DIY due to giving more flexibility to design things or react to unexpected framing in your roof.

 

[pookguy88]

For a DIY install it's smart to make your life as easy as possible. All the mini products need more precision. Having the old school 12 or 18" wide flashing gives you more room to recover from a mess up vs zero flashing or 6" wide flashing. Also some of those reduced flashing products cost more

IronRidge is pricier but it is stronger and has a longer span/cantilever distance than say Unirac SM light. Which also facilitates first time DIY due to giving more flexibility to design things or react to unexpected framing in your roof.

That’s what I want right now as a first time DIYer, easy as possible. I guess I’m looking at IronRidge, thanks for the info.

 

[zanydroid]

That’s what I want right now as a first time DIYer, easy as possible. I guess I’m looking at IronRidge, thanks for the info.

No problem. I'm about 75% done with my first install using SM light and I have to go scrounge up an extra rail because staying within the engineering guidelines required me to use more rail than the design said I needed (joists slightly off from expected)

 

[zanydroid]

That said it's not guaranteed that IronRidge can prevent similar cases, I wish I had purchased x% extra hardware and rail, esp the rail since that has to either be picked up locally, shipped freight, or pre cut to UPS size. Pretty annoying.

This is no big deal to a installer since they always have extras sitting around

 

[Tulex]

I went with Unirac and their Flashloc. No flashing with these.

Super easy to install, and cost less, at least for me, than ironridge. They also have a design page.

Locating the rafters wasn't an issue. I easily found them just by tapping with a hammer. Of the 20 I've installed so far, I only missed the rafter one time, and that was close enough that the mount still covered up the missed hole.

 

[zanydroid]

That's the kind of product I'm concerned about with a first time solar/roofing/joist attachment project. You probably have to hit within 2" of the joist on the feeler, and you very likely have to know in advance how to patch shingle.

 

[Tulex]

That's the kind of product I'm concerned about with a first time solar/roofing/joist attachment project. You probably have to hit within 2" of the joist on the feeler, and you very likely have to know in advance how to patch shingle.

Mount is around 4 inches wide, so you have to be 2 inches off for it to not cover a missed hole. I wasn't concerned, as they provided the sealant to fill the mount. Had a missed hole been outside of the mount, I'd have just filled it with the sealant. It's only a 3/16 hole you have to drill, it will seal easily.

 

[zanydroid]

Ok. I didn't find a full reference to the pros and cons of different kinds of new roof hole sealing.

So I ended up using thin gauge galvanized shingles for every way off hole that the flashing does not cover. And then sealing above and below the shingle patch.