Best Way to Seal Bolt Penetrating Roof


#1

I’m mounting a solar water heater panel to my roof. It requires four bolts through the mounting brackets, shingles and decking, and into the attic. The instructions mention a galvanized washer and neoprene washer above the bracket, and flashing and silicone sealant under the bracket.

Is there a standard way to seal bolt-on brackets on an asphalt roof with 8x12 pitch?

Thanks for any info.


#2

Nope, it’s a hack job any way you slice it. What you just wrote is the thing to do.


#3

How should the flashing be applied?

I’m guessing cut to 1’ x 1’, stuff it under the tile above the bolt hole and silicone heavy underneath it and where the bracket meets it?

Should the low side of the flashing be left open so any water that gets in can run out?


#4

The best way to do this it to mount it to the fascia board below the roofline. You will never have a roof problem resulting from penetrating your water-shedding system.


#5

Aaron, this isn’t a DishTV system; this is for large panels that are somwhat sizeable, like 4’x6’ or more.

Really, I would suggest you go with the mfg’s instructions & really snot the heck out of it up top (making a clean coating, of course). Understand that there very may well be problems you will have downline.

Where are you located? Different types of coatings or applications may be suggested over other brands / types. Make sure you don’t trap any moisture in there to begin with.

Also understand that an 8:12 has a bit more vertical ‘pull’ on the roof against the slope / deck as opposed to a lower pitch that might have more of a push down against the decking. I have seen some older homes with 3.8" decking & don’t know if this kind of a weight is going to be detrimental to it over time.

If you don’t have a substrate that’s going to fully support it, then you may consider adding additional decking & rafter support form underneath.


#6

How large is it?


#7

HUGE Aaron. You had to have seen solar panels before. This guy thinks you’re crazy right about now, but we understand ya! :smiley:


#8

I’m with tar monkey on this, this is a hack job anyway you slice it. Can’t avoid using tar on this, promise you that. Or… you could build pitch boxes for each protrusion, but I’ve seen pitch boxes shrink and leak also.


#9

Hello,

I ran across this skypowersystems.com/document … lation.pdf doing a Google search. You should be able to use it on a shingled roof as well.

Keith


#10

I like that Unirack system… looks like it does a good job of distributing the load across a wider footprint.

***HOWEVER.***.

What is the purpose of bending the edges of what appears to be a lead jack type foot in the shape of turnback metal? Under the tile pieces, I can see the importance… on the reveal seems somewhat useless.

If it’s a shingle roof (either 3T or Comp) then there’s not anywhere near as much height or gap between the roof deck & the topmost portion of the shingle (in their pic, the top of the tile). I guess in retrospect this doesn’t make much difference… or does it?

I have done TWO houses with solar setups; one for water panels, the other for photovoltaic. In both cases, it was someone’s else responsibility to waterproof the pen points (as well as do the mounting to begin with).

Typically, they (again, not me) use an L or C channel shaped shaped bracket that gets foot bolted right through the roof shingles & roof deck.

BTW, that should have read 3/8" in the post ^ & not 3.8"…


#11

I have seen them…I simply did not read thoroughly before posting, thanks for understanding. Pitch pockets, or retrofit pipe boots, I say.

Pitch pockets, when filled with the proper materials (not roof cement) can be leak-free for a long time. Google search Portals Plus. They may have something to fit your needs.


#12

I’m in South Louisiana. The panel is 4’ X 8’ and weighs 175lbs dry + 30 gal @ 8lbs per gal = 415lbs wet

The pitch pockets sound possible, do they work on a steep pitch.

Thanks for all the good info.


#13

aw gee nothin left for me.
good thing.

gweedo


#14

pitch pockets are generally a flat roof application, but you can make it work with shingles as long as you flash it right… bring the shingles even across the bolt line, install the pitch pocket over the shingles, then shingle right up and over. Not a big deal. Two things with pitch pockets, one, make sure there is not a void where the “pitch” or whatever you use (pourable sealer?) is or it will settle into the void and make a huge mess below wherever the hole goes and you might end up with an empty hole instead of a pitch pocket, and two, if you use pourable sealer, make sure you prime the insides of the box or it will leak… see rubber roofing specs on pourable sealer before starting.


#15

Pitch pockets can work on a steep pitch as long as theyre fabricated properly…with a wide flange, seam down, top edge pitched level, and filled with a polymeric sealant like Weather-Tite Hurricane Force Universal Sealer. You can find it at wttus.com


#16

i agree with Aaron make shore you tell the sheet metal mechanic the pitch
of the roof or more thane likely he will make it flat .
if it is galvanized don’t use copper it will cause electrolysis and you will have to do it all over agin


#17

I read the skypowersystems link, and think this is a really good way to solve the problem.

However, I am thinking about welding the solar panel bracket to the top of a short piece of thick walled aluminium 1" ID pipe and running a bolt or piece of all-thread all the way throught the pipe and into the attic. This way I only have one hole per mount to worry about.

Then I can use a standard roof jack/flashing http://www.bestmaterials.com/detail.aspx?ID=8861 on the pipe and bolt the solar panel on top per manufacturers instructions.

Any thoughts on this approach would be appreciated.

Thanks.