Solar install roof question

Desertsky

Active Member
Hi fellow travelers! I am going to install a couple solar panels on the roof of my 2010 North Trail 26RKS to keep the batteries charged during boondocking and when in storage.

The question I have is how thick is the composite material on the roof? I recently had to replace a tail light and the material back there is about 1/4 in thick. I am planning to use rubber well nuts to attach the panel clips to the roof.

http://www.ebay.com/itm/RUBBER-NUT-...427755?hash=item237fb50f6b:g:OlcAAOSwsW9Ywc5-
 

Silverado23

Iowa Chapter Leaders
Hi fellow travelers! I am going to install a couple solar panels on the roof of my 2010 North Trail 26RKS to keep the batteries charged during boondocking and when in storage.

The question I have is how thick is the composite material on the roof? I recently had to replace a tail light and the material back there is about 1/4 in thick. I am planning to use rubber well nuts to attach the panel clips to the roof.

http://www.ebay.com/itm/RUBBER-NUT-...427755?hash=item237fb50f6b:g:OlcAAOSwsW9Ywc5-


If I remember right it is roughly 3/16" thick. I have a roof cross section sample that I can check to verify.
Basically the roof is, 1/16" Rubber membrane, 3/16 OSB, variable 4" Foam , 1/8" interior panel

When I did my solar panels, I just glued them on using butyl rubber adhesive and dicor on the edges. Thin film solar panels.

By installation is in this thread.
https://heartlandowners.org/showthread.php/55425-Solar-installation
 

Desertsky

Active Member
Thanks for the quick reply. I haven't been up on my roof but it appears that the fiberglass front wraps over the top. I can't tell if it continues on or not. I am bringing it home from storage tomorrow and will check it then.

I am using a couple of Renogy 100W panels I used for a solar generator project.
 

crazybanshee

Well-known member
I just used some dicor under each mounting foot and used a screw into the roof. They have been up there for 10 years without an issue. No leaks.
 

schew

Well-known member
If I remember right it is roughly 3/16" thick. I have a roof cross section sample that I can check to verify.
Basically the roof is, 1/16" Rubber membrane, 3/16 OSB, variable 4" Foam , 1/8" interior panel

When I did my solar panels, I just glued them on using butyl rubber adhesive and dicor on the edges. Thin film solar panels.

By installation is in this thread.
https://heartlandowners.org/showthread.php/55425-Solar-installation


Are you sure when you say 3\16"? Maybe you meant 3/8" as they don't make 3 \16 OSB.
I cannot imagine the roof sheeting is 3\16". . If made with 3\16" sheeting it wouldnt be possible to stand on your roof inbetween rafters and not have your foot fall through..
 

Dennyha

Well-known member
Yes, I believe the OSB is 3/8".

Some have reported back that rubber well nuts did not perform as expected. Many, including me, have placed dicor under the mounting foot, screwed it down with 1" SS screws, and then more dicor over the screws. I have not read any cases where this practice did not perform well.
 

Az_Ernie

Well-known member
When we installed our Trav'ler Sat Syst, the wood paneling under the rubber roof was 3/16" (Heartland Eng. Drawing shows 5.2mm Luaun plywood). Not 3/8" OSB. It was such a concern that I purchased a mounting plate from Winegard to enlarge the sat dish's foot print. The plate was mounted to the roof with threaded nut inserts (can't remember grip length). Any place the roof was penetrated, Dicor was used to seal holes. The factory backing plate was located in a place on the roof that would not allow for the clearances that our Winegard Trav'ler required to rotate freely.
 

Desertsky

Active Member
Yes, I believe the OSB is 3/8".

Some have reported back that rubber well nuts did not perform as expected. Many, including me, have placed dicor under the mounting foot, screwed it down with 1" SS screws, and then more dicor over the screws. I have not read any cases where this practice did not perform well.

In what way did the well nuts not perform as expected? I would expect them to hold the panels in place. I would not expect them to be completely sealed by themselves.
 

Silverado23

Iowa Chapter Leaders
Are you sure when you say 3\16"? Maybe you meant 3/8" as they don't make 3 \16 OSB.
I cannot imagine the roof sheeting is 3\16". . If made with 3\16" sheeting it wouldnt be possible to stand on your roof inbetween rafters and not have your foot fall through..

Looking at the actual roof sample from a north trail 3/16 sheathing 1/8" interior panel and variable foam

If you want confirmation on your unit you should be able to remove the interior from from a vent and move the roofing material out of the way to measure yours.

Here is the roof sample that I have.
Cross section crosssection.jpg
Interior view CrosssectionSample.jpg
Roof side without the rubber membrane Interior.jpg
Interior material thickness InteriorThickness.jpg
Overall cross section thickness measuredoverall.jpg
Roof material thickness Roofthickness.jpg
 
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Dennyha

Well-known member
In what way did the well nuts not perform as expected? I would expect them to hold the panels in place. I would not expect them to be completely sealed by themselves.

I read a post or two where the owner went to remove the panels to transfer to a new unit, and was shocked to see they could just lift the panels off of the roof without removing the well nuts. I guess over time the rubber deteriorated and contracted, and was no longer gripping the hole.
 

Desertsky

Active Member
Thanks for all the replies. I installed two 100W Renogy panels on the roof and anchored them with #12 sheet metal screws. The screws gripped pretty good into the material. I sealed everything with white self-leveling EPDM sealer. I ran the wiring inside the bedroom wall where the electrical plugs are but kept the wiring well away from those wires to prevent induced interference. I mounted the MPPT controller on the back wall of the wardrobe closet above the fuse panel. It is cool to see 5.5A panels giving 7A charge to the batteries!

I checked the batteries and found that the previous owner had used automotive starting batteries instead of deep cycle batteries. No wonder they didn't seem to be holding a charge very well! Probably had been deep cycled a few times and were damaged. Oh well, next on the list is a couple of good deep cycle marine batteries!
 
I had solar on the roof of my last trailer, and left it on the rig at trade in. Solar was mounted quite well. Think I will use the portable units that plug in below. Since I plan on having a cover over my Bighorn, the solar panels will not work anyway, but I can place a portable unit outside, but will probably hook up a 50 amp for power anyway? Seems to me the disadvantage of portable solar panels are they can walk away and one must store them? On the roof panels are harder to clean and can from bird guano and dust, plus can be damaged by low trees?

Bighorn 3270RS Chevy 2500HD 4x4 Diesel
.
 

Desertsky

Active Member
Just a quick update. Just did 9 days of boondocking while elk hunting. The place i was camped only got about 2-3 hours of sun a day due to the steep hills. It kept the two 6V, 232A Interstate deep cycle batteries charged enough to run the heater and lights at night. I did run the generator to make coffee in the morning and microwave meals in the evening.

It got down to 9 degrees one morning so the heater got a great workout. Heater duct routing sucks in this model! The "engineer" that came up with it should have to live in it for a month in cold weather! Virtually no heat to the bedroom and water pipes froze in kitchen! That goodness for the Big Buddy portable heater!
 
I've got a Renogy 400 watt set that is about to be installed in our RG28 Toyhauler. I have tons of open roof space so we may go larger than 4 panels. But finding a place for litium batteries is going to be a challenge. Looking at putting those under the front bed area.

I would like to find a bracket that has a way to at least adjust to the sun to get maximum power. Do they have something like that for RVs?
 

Silverado23

Iowa Chapter Leaders
I've got a Renogy 400 watt set that is about to be installed in our RG28 Toyhauler. I have tons of open roof space so we may go larger than 4 panels. But finding a place for litium batteries is going to be a challenge. Looking at putting those under the front bed area.

I would like to find a bracket that has a way to at least adjust to the sun to get maximum power. Do they have something like that for RVs?

How many batteries are you planning?

I just used 3 deep cycle lead acid batteries and found a nice box that holds 3 group 29/31 batteries on the tongue. Even running the furnace and having nearly 800 watts of solar I rarely run the batteries down. However, I only power the 12v circuits currently and do not use an inverter, yet.
 
I considered a 3 battery tray as well for the RG28. We plan on boondocking a fair bit but have a Champion 3500 generator and a 14 gallon fuel tank to feed it. I can get 2-3 days running non stop with it. So 3 29/31 series batteries would be a good start. Don't plan on running much other than heater fan or roof vent when needed. Then led lights at night for reading.

I already have a 2000watt Xantex inverter I can put in it but haven't gotten to the wiring part yet. Focusing on the mounting of the gear right now.

Can you tell me where you found the box and what it is?

Thanks!
 

Desertsky

Active Member
I've got a Renogy 400 watt set that is about to be installed in our RG28 Toyhauler. I have tons of open roof space so we may go larger than 4 panels. But finding a place for litium batteries is going to be a challenge. Looking at putting those under the front bed area.

I would like to find a bracket that has a way to at least adjust to the sun to get maximum power. Do they have something like that for RVs?

I wouldn't worry too much about that. Even on a flat roof you will get probably 75% of the available power. Unless you want to keep adjusting it throughout the day, that is the best average you will get. Getting an MPPT charge controller will make more difference than that over cheaper controllers.
 
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