MWeiner

Fiberglass vs. Metal Roof

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MWeiner   

Did any of you purchasing a Class B motor home give consideration to the fact that a fiberglass roof with seams has a much better chance of leaking than a metal roof straight from the factory with some penetrations for a fantastic fan, etc. ??

I was concerned that the reconstructed roof of a Class C coach like the Winnebago Navion or similar models would NOT be as sound as the inside conversion of my Mercedes Benz Sprinter van.  

Further, I'm thinking of having solar panels installed on the roof and integrated into the electrical system. While I have a professional installer who knows what to do, it's always a risk when you penetrate the membrane of the roof. 

What have been your experiences with this..?

I presume that it's worth the risk to get solar?  If it weren't done after market by my installer, it would have been done by Roadtrek in my case.  A penetration is a penetration. 

My decision to get the Class B motor home was based on three things,  

1. Way it drives, and manueveable handling.

2. Extremely high MPG for a vehicle of this size.

3. Lower maintenance and repair, especially of the roof seams and seals.

Your thoughts would be appreciated. 

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MWeiner   

The guy that would install them for me professionally told me that he could easily get two 160 watt panels up there for a maximum output of 320 watts. 

He wasn't sure about a 3rd panel??  And, he would wire that to the electrical system with a charge controller...

The two panels installed would be around $1,100.  If that could give me a little more peace of mind when boon docking, I would consider this money well spent.

The coach has two AGM deep cycle 6 volt batteries in series under the hood. 

They're Centennial batteries, here they are below...

https://battsys.com/centennial-battery-cb6-224-6-volt-224-amp-hour-sealed-lead-acid-agm-battery

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M,

Read this first Solar Bobs Charging puzzle at solarbobsolar.com.  It is solar 101 and will explain the pit falls associated with the industry. Once you have read it read it again and then more of his blog. I followed his advice and have done many days of boondocking since. Several ways of installing the system. As for penetrations, not a problem if done correctly and many are not. Some are designed to leak like my original TV setup. You need to be involved, need to see what is happening, asking questions.  Wire size is important, bigger is better! Carmanah panels @ 160 watts are 27 X 52 inches, pre-plan the install and then consult with the fellow that will do it or do it yourself, It is not difficult. Send me a PM and I will explain further.

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MWeiner   

Thanks for this.  Question, are two 160 watt panels enough to keep my twin 6 volt batteries charged up...

I know that it won't be enough to run the AC. @😁😁😁

Listen, the guy who installs my stuff...for my private cars.... proximity sensors, back up camera, custom radio and amplifiers, speakers etc. has been doing this for over 25 years. He is my go to guy for all mobile electronics.  

When he installs something.. like the new radio navigation system I put in the coach recently, you can't see how he does it... wires are not visible anywhere.   Truly magic. He just installed a new back up camera and front camera all integrated into the new dashboard system with a 7 inch screen... very slick.     The new mircophone to pick up voice is a tiny one just popping out of the headliner near the windshield...

I'm going to be very involved and will certainly ask him about the size of the wires...he is very trustworthy and really backs his work 100 percent.

He even does work for dealerships in the area with new cars. 

Hmm, I had some difficulties locating Bob's solar website...was that 

Solarbobsolar.com

Didn't work for me???

SO, do you think I'll be able to get enough bang for the buck on these two panels? I imagine it's better than nothing?  

I really don't expect to be boon docking that much, but, keeping the batteries charged is much more desirable than letting them get deeply discharged. 

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It might be solarbill.com.  I have 800 watts with an MPPT charge controller and 6 Centennial AGMs.  Bright sun charges up to 40 amps with low batteries, cloudy 0-5 amps.

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jleamont   

To answer your question on roof seams, YES that was a determining factor when we were shopping for our DP. Design and serviceability were #1 on my list while shopping since I do my own maintenance. As a result of this we didn't get the floor plan we would have liked to have, after having this coach we soon realized this floor plan worked out better for us anyway. Some have seams with a large rectangle toward the center of the roof and others like ours does not, the more seams on a roof the more maintenance you will need. I would prefer an all aluminum skinned and roofed coach.....someday :wub:

We don't do solar, one more gadget to break, the overall expense, little net gain and more holes in a roof = more places for water to make its way inside.

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320 watts = just over 26 amps @ 12 volts, this would be a good charge rate for recharging the system. As for metal vs fiberglass, my coach is 41.5 feet long, is metal 37 feet with a fiberglass cap front and rear. I have to reseal the cap seams about every 5 years. Any holes in the roof will need attention, I inspect those yearly, and am prepared to do a little touch up work at anytime. Since there is movement, going down the road, shake rattle and roll, one can not expect to have some maintenance even on a Mercedes Benz. The reason Daimler bought Chrysler back in the late 90's was for the purpose of getting into the van business, while owning it, they tried to perfect the Dodge van to the sprinter and did a good job of it. When they sold Chrysler off, they only took the Sprinter with them, but left the Sprinter chassis and design for Dodge to continue.

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MWeiner   

Thank you all for your replies... I've had several cars with sunroofs and never had a problem ( lucky I guess) with leaking roofs.😀

Kay, interesting to know about the Sprinter history there... Yes, I was aware of the Daimler Chysler connection.... from what I know Mercedes Benz wanted to keep the exclusivity the Sprinter and when they split with Dodge, the Dodge folks started producing the RAM ...are you saying that the RAM is on the same chassis as Mercedes?   

In any case, I figured that having a metal roof from the factory would be a better fit for longer term maintenance costs and performance..   I don't have any fiberglass caps or seams.. there are seals around the A/C and antenna.  Not much... 

As for vibration, I suppose anything could happen, but, my installation guy is VERY professional.. 

I would hope had more issues chasing water seals and seams on the fiberglass caps of the Winnebago Navion 😁😁😁.   The Navion was very nice inside and I seriously considered getting one, but, the extra weight on the sides and the more top heavy box made the unit feel NOT as light on it's feet as the van. I was also concerned about how the aerodynamics of the larger box would perform in high winds and of course, the extra box is more of a sail with lower mileage. All of those things steered me into the Class B. 

The Navion is sometimes called a Class B plus.... but, I think it's really a Class C. 

SO, the two panels for 320 watts should be fine... GREAT. 

 Desert deals, I see you have the Centennial batteries.. just got my Full River batteries replaced... hopefully these Centennial batteries will be good... have you had a good experience with them??

As for the risk of having the solar...the whole rigs a risk to some degree...I'd rather have the extra power...if I'm out on the road. 

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I have had coaches with metal roofs and fiberglass, I have worked on a rubber roof but never owned one. I don't see a big difference as long as you keep up on the maintenance. You are going to have seams and penetrations in any roof. Ok I thought the aluminum roof on the 1978 Executive was pretty solid but you still had to maintain the seals on all the penetrations.:D

Bill

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MWeiner   

Bill, I suppose anything can fail, but, metal roof especially from the factory are not as likely to leak, there's a lot more seams on the fiberglass caps..   I'm not particularly worried about anything that came from the factory or the conversion... 

AND, there's no ladder to the roof of my rig.😁😁😁

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All roofs on motor homes will have issues. They all must have penetrations by anything mounted on them. If not maintained there are going problems. We are driving down these wonderful maintained roadways in a rolling earthquake. They are going to have issues.

Also just because a coach is brand new right out of the factory, don't think there wont be problems. There have been post here where the entire front cap was only attached by the sealant, not one screw. So brand new doesn't mean no problems.

Herman   

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jleamont   

Bill, most coaches that I have stumbled across with rubber roofs also have less insulation and a much thinner roof structure. I have to replace a gasket on my rear AC unit tomorrow, I wanted new mounting bolts for the AC, as mine are chewed up from someone prior to us owning it, because Monaco has such a thick roof (distance from the inside ceiling to the top of the fiberglass roof) they are special order, so I am going to weld nuts to the hex portion so a socket will fit properly, I'm not waiting for hardware. Turns on the standard bolt length is 1/2 the depth of ours. Where am I going with this.....I have been inside many Motorhomes and Trailers in rain storms, they are very loud inside when it rains, the only thing they had in common was a rubber roof, our coach you don't hear it unless its a heavy down pour and then you have to shush everyone and mute the TV, we typically only notice hail.  Our C if it was drizzling you would swear it was hail and it sounded like the end of the world was coming :lol:.

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Joe, I don't hear rain inside mine either, only been inside with small hail, didn't know it till I looked outside. The only clue I get for heavy rain is when the awnings automatically drop because of the extra weight, that happened in Tennessee last week, poor Sue jumped out of bed, thought that someone had hit the coach.:o

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The composition of the roof doesn't bother me as long as it is maintained. The outher thing to watch for is leaking around the windows. I would bet most of the sidewall delamination I have seen came from leaks around windows.:o

Joe, I agree the better built coaches with more insulation, thicker roofs are quieter.  

Bill

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32 minutes ago, BSMEATON said:

Where are there seams on a fiberglass roof?  I thought they were 1 piece?

Any place you have a penetration can leak. There was a thread awhile ago about the seam where the roof and sidewall met I think Winnebago has a problem if you don't keep up with the caulk in that joint. Little things like the roof peeling off.

Bill

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jleamont   

Tiffin has a multi joint fiberglass roof, about 3" from the outer edge, well at least my friends Allegro Bus does anyway. It has fasteners all the way down with Dicor over them. Ours just has a paint/no paint line, the seam is on the side wall under trim.

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Typical seams on a Safari are two, one at each end between the roof fiberglass and the cap structure. It is generally covered with a molding and then a self leveling sealant. Sides are tied down under the drip channel molding.

The Safari roofs are 3 and 3/4 thick. The later coaches 1999--2002 at least are a sandwich of luan and white bead Styrofoam and are very noisy!  How thick are your "thicker" roofs?

Hey Joe, sent you a PM with some questions, no answer? Did you get it?

B

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BSMEATON   
14 hours ago, WILDEBILL308 said:

Any place you have a penetration can leak.  

Kind of true with any roof isn't it?

I understand on the seams now, caulked seams vs welded on a conversion van.  

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