Locating Trusses on a metal roof


#1

I have been contracted to install solar panels on a metal roof which was laid over top of the old shingles. Can anyone tell me how I can locate the roof trusses in this type of roofing? I need to secure the solar racks to the trusses. Intelocking panels of about 12 x 60 were used for the roof.


#2

Hi,

Something does not sound right. Connect to the trusses?

They make panels that lay in side the ribs.

Sounds like that is going to be one ugly, leaky roof when you are done.


#3

Go up in the attic and knock on the roof while someone else is on the roof knocking back. It’s a good system for finding areas of leaks or where work has to be done. This person should be familiar with the metal system and get to work taking panels off so you can drive a nail right next to the truss so your bro on the outside can spot the ones you need to secure to. Measure the distances of the truss center points and mark at the ridge and at the eave and snap lines with blue chalk.

Are you wiring the solar panels too?


#4

seams like screwin through matel shingles then deckin
would be enough to hold any residentual solar.

ditto lefty.

but if you have to get a rafter then your gonna have
to do it from attic.
get ya a small long drill bit (1/8"), and drill up a whole rite against the rafters you need to hit.
then rooftop, you can screw panel in 1" to the
left or right side (dont forget what side of the rafter you drilled on).

dont worry bout the little whole,
youll probably seal it when you bolt down
with silcone.

good luck.

gweedo.


#5

Guys, thanks for your information! You brought up an interesting question though. When installing solar panels on a rack mount system you are told to secure them to the rafters when its a regular shingled roof. With the metal roof over the shingles, does it really matter then if I attach to the rafters? Will attaching to the decking be enough? Thanks again!


#6

Well, since your ID states Toronto, I’ll assume you’re up yonder there…

I will also assume your primary concern is going to be freezing moreso than high winds?

Personally, I’m all for a truss supported installation, however if you’d like to go heavyweight / overbuild you could always measure up & mark the exact location you want soas to avoid ribs & other interferences (plus align for the best solar collections possible) & drill through the roof deck irregardless of what’s underneath.

Once your holes are located, go into the attic & reinforce from the inside with 2x6’s connected to the truss system. This will better distribute the heaving you might see on the roof deck & metal panels.

Oh, & be careful when using certain sealants that have been known to cause galvanic reactions. Go to a shop that supplies metal roofing parts & get a few tubes of what they sell (if the roof is a colored series of panels, then you can get a match which while barely visible with your panels might look a slight bit better).

When in the attic & prior to drilling, I’d look for any hidden electrical wiring you might have up there; you never know what’s going on with any prior work, satt. dishes, etc.

Speaking of sattellite dishes - if they have one on the roof, see if it can be relocated to a chimney or the eave if it’s going to need a move due to your solar system.


#7

ditto ranchhand.

gweedo.


#8

[quote=“SamfromSeattle”]Go up in the attic and knock on the roof while someone else is on the roof knocking back. It’s a good system for finding areas of leaks or where work has to be done. This person should be familiar with the metal system and get to work taking panels off so you can drive a nail right next to the truss so your bro on the outside can spot the ones you need to secure to. Measure the distances of the truss center points and mark at the ridge and at the eave and snap lines with blue chalk.

Are you wiring the solar panels too?[/quote]

\

Did you say go int the attic?
Have ytou ever tried that in the summer?
You would burn up. Literally.
I had to to do that a coulpe years and wont ever do it again.
Seriously its way too hot. Well the one i was in was. It had to be around 50-60 degress. Not kidding. Maybe even hotter.
It was a new constriction home but was in its final finishing stages.
If you can find another way then do it cuz that crazy.
Usually the trusses are space equally apart so if you fing one youi can find them all.
Just remember the sheeting of the roof well be inforced in those areas
Peace.


#9

First, let’s all remember that roofingbuster is a Canuk & as such, they use Celsius vs. Fahrenheit.

Second, R-B, how about getting in the attic around 8 or 9a? Shouldn’t be that difficult a process earlier in the day, don’t-cha-think?

:slight_smile:


#10

[quote=“RanchHandRoofing”]First, let’s all remember that roofingbuster is a Canuk & as such, they use Celsius vs. Fahrenheit.

Second, R-B, how about getting in the attic around 8 or 9a? Shouldn’t be that difficult a process earlier in the day, don’t-cha-think?

:)[/quote]

im not too sure why it was so hot but out side it was about 25 20. I just recebtly had to replace a defected vent and holy smoke when i pulled that vent loads of air came out hot. I put my arm inside and dame it was hot.
Here they out that attic this inside to it does get really hot.
There not reall attics there more for storing small thing and come to think about i dont thgink your suppoesed to stor thing up there.
The way they do the new trusses now. They are small and pre essmbled so not much roo to work.
Peace