RV Roof Panels

[Lt.Dan]

If you want something that costs more than unistrut, but is lighter - look at the 8020 aluminum. If I ever do another Solar on a RV I will look closely at laying down some 8020 1" rails, Then build on that.

I'm not too worried about weight. The trailer already weighs 22k lbs loaded, whats a few hundred more lbs? Lol!

 

[HRTKD]

If you want something that costs more than unistrut, but is lighter - look at the 8020 aluminum. If I ever do another Solar on a RV I will look closely at laying down some 8020 1" rails, Then build on that.

There is aluminum low profile unistrut, or maybe it's unistrut-like.

 

[chrisski]

I think you have a decent plan and hope to see this in the show and tell once its built.

 

[Lt.Dan]

Any idea on how to seal the holes with unistrut after it's screwed in? Maybe just that butyl tape? Or lay some dicor down, then screw through the hole?

 

[chrisski]

Not sure of your roof, but for my wood roof covered with the rubber mat (EPDM?), I secured the aluminum mounting bracket with two sided butyl tape for the length and width of the aluminum, drilled a hole, put DICOR self leveling lap seal colored to my roof in each hole, put a bolt through to the roof, and then used DICOR self Leveling lap sealant on top of the screw holes and around the outside of the bottom of the aluminum mount. It’s nice and firm. Just tighten the screws, but not so much they spin in the holes and strip them. Surface prep is key.

I used 4 bolts per side of each 100 watt panel. I used a tube of DICOR per panel.

I don’t like the idea of putting roofing tape to secure something that the screws in Without waterproofing first. With the ways I’ve installed roofing tape, there’s a tiny, tiny gap where the tape overlaps I think water could find its way into and then eventually to the screw holes. I do have a couple of flexible panels I just installed with this overlapping tape, but I did not drill into the roof at all.

 

[babybober]

OK, so just playing devil's advocate here. I am only putting 600W on my RV roof with possible expansion of another 200. I limited panel placement to assure sufficient access to all roof components and fixtures for repair, resealing, etc. Looking at your layout, I certainly wouldn't want to be the one to have to do normal cleaning of the radiator fins on the end two AC units, etc... While maximizing solar, don't do it at the expense of not being able to maintain the RV.

 

[Whinny]

Like chrisski said but use eternabond doublestick instead of regular butyl tape, comes in various widths. It is a little harder to work with because it sticks to everything.

Eternabond Doublestick Permanent RV Roof And Leak Repair Tape, 1'' x 50'

The Eternabond EB-6D010-50R Doublestick Permanent Roof And Leak Repair Tape is durable and easy to apply. Once bonded, you will never have to worry about leaks in your RV, trailer or motorhome again.

www.rvupgradestore.com

 

[babybober]

Like chrisski said but use eternabond doublestick instead of regular butyl tape, comes in various widths. It is a little harder to work with because it sticks to everything.

Eternabond Doublestick Permanent RV Roof And Leak Repair Tape, 1'' x 50'

The Eternabond EB-6D010-50R Doublestick Permanent Roof And Leak Repair Tape is durable and easy to apply. Once bonded, you will never have to worry about leaks in your RV, trailer or motorhome again.

www.rvupgradestore.com

While I am a complete proponent of eternabond in general, I would be hesitant here. Eternabond doublestick is thin unlike butyl tape (60mils I believe). As such, there really is not enough thickness to contour sufficiently between rigid surfaces that have no give over any longer distance and we all know that RV roofs are far from completely flat unlike an aluminum rail.

 

[HRTKD]

While I am a complete proponent of eternabond in general, I would be hesitant here. Eternabond doublestick is thin unlike butyl tape (60mils I believe). As such, there really is not enough thickness to contour sufficiently between rigid surfaces that have no give over any longer distance and we all know that RV roofs are far from completely flat unlike an aluminum rail.

Agreed. I'm a big fan of Eternabond for repairs. My roof is practically held together with Eternabond. But for under the mounting brackets, a good thick butyl tape is the way to go.

 

[chrisski]

I actually used a two sided Eternabond tape. To me looks like butyl.

This is the product:
https://www.amazon.com/EternaBond-D...d_rd_i=B00JEH8EKI&psc=1&ref_=pd_bap_m_rp_1_sc

That tape will make you think you don’t need to put screws in. It’s strong enough that instead of ripping off, it’ll tear the roof off from underneath it, so screws are a must.

 

[babybober]

I actually used a two sided Eternabond tape. To me looks like butyl.

This is the product:
https://www.amazon.com/EternaBond-D...d_rd_i=B00JEH8EKI&psc=1&ref_=pd_bap_m_rp_1_sc

That tape will make you think you don’t need to put screws in. It’s strong enough that instead of ripping off, it’ll tear the roof off from underneath it, so screws are a must.

Butyl tape typically is 1/8 thick but you can get 1/4 and 3/8 thick also. And tape is a poor term as it is not really tape but more like a putty. As I said, I love eternabond in general but from what I have read the double stick was designed for seaming roof membranes where there is flex in both surfaces . Using eternabond in this application you really need to make darn sure it is 100% sealed on all surfaces...

 

[Lt.Dan]

Will the butyl tape or eternabond be enough to seal without the dicor? Or is lap sealant still required?

 

[HRTKD]

I consider butyl to be your last line of defense. The Dicor is the first line. Seal the edges of the bracket and then the top of the screw.

Every piece of external molding on a trailer with fiberglass sides has butyl tape under the molding, then some sort of sealant along the edge(s) of the molding.

 

[babybober]

I consider butyl to be your last line of defense. The Dicor is the first line. Seal the edges of the bracket and then the top of the screw.

Every piece of external molding on a trailer with fiberglass sides has butyl tape under the molding, then some sort of sealant along the edge(s) of the molding.

Agreed, I put a thin line of lap sealant on the edge of the Eterna bond tape JIC. But then again I also wear both suspenders and a belt.

 

[texskeet]

Dicor is it lay metal down drill hole or starter hole pick metal up put blob of dicor put metal down then screw it down will never leak. Dicor is the best.

 

[Lt.Dan]

If I lay down Unistrut and have to dicor the entire thing (all the way around, and all inside because of every hole), then I'm going to go through a case of dicor very quickly!

 

[texskeet]

just where the screws are about size if a 23 cent

 

[HRTKD]

I'll gladly go through a case of dicor to save my trailer from water intrusion.

I don't use a starter hole, but only because the screws I'm using a self tapping. There are already holes in the bracket feet, so I don't have to drill that on the roof. Too much drilling/screwing with Eternabond in place can cause it to thin out. The Eternabond is so darn sticky that it can wrap around the drill bit and the screw, pulling material away from other areas. Butyl is more forgiving.

 

[texskeet]

Be best to have starter hole so dicor goes in the screw hole too.

 

[HRTKD]

Be best to have starter hole so dicor goes in the screw hole too.

It's not something I've done. I had to think about it. My only concern there is that the Dicor would act as a lubricant on the threads, possibly allowing the screw to back out. Yes, the Dicor is sticky, but without exposure to air, I'm not sure it would cure well. I dunno, maybe it's sticky enough that it would act like glue instead.