Finding roof rafters

[twinster2]

Does anyone know of a good way to locate aluminium roof rafters on a 2010 189FBR? I want to mount a 100 watt solar panel and I want to mount it to at least one rafter for safety.

[profdant139]

Wow -- that's a tough question. No way to locate them from the inside, since there is that thick insulation in the ceiling. And I do not know if a magnetic stud sensor will work on aluminum.

I'll be watching this thread, hoping to learn something!

[Rocky Mtn marmot]

I've tried stud sensors for the walls, no luck. Solar panels on thr roof only work if you will park in full sun. I park mostly in shade, much cooler in trailer. I use a portable 100 watt panel with a long cord so I can place it in the sun and move it as the sun moves.

[profdant139]

twinster, I should add that I use a 120 watt portable panel, with great success, because we usually park the trailer in the shade. If you use a longer cord (as I do), make sure it is heavy gauge -- a lighter cord will cause a drop in the voltage.

[jbfunfinder]

Twinster- If you search on this forum, "Fun Finder Solar Install Part 2", you will see what I wrote a few years back about securing solar panels to the roof. I am certain there is no need to find the aluminum roof frame and besides, they are not likely in the ideal location anyway. Between the Dicor's stickiness and the well nuts' grip those panels are going nowhere. I have now used this same technique on three trailer solar roof installs. This is not my idea. Renology's RV install guide from several years ago illustrated the well nut technique. MUCH more important IMO is not mistakenly drilling into an electyrical wire crossing the roof in the space between roof skin and ceiling luan. Dip that drill bit carefully and very shallowly.

[twinster2]

Jbfunfinder- Thanks for the advice. Did you use butyl tape under the aluminium feet when you screwed them down? Also, I looked at your posting and was wondering if you put dicor on the screw heads since your picture didn't show that you did.

[jbfunfinder]

Twinster- If you check "Fun Finder Solar Install Part 3" on the search, you can see a photo of a completed installation. I did not use butyl tape, although I don't see any reason why you couldn't. Instead, I puddled a small amount of Dicor lap sealant on each of the 8 well nuts just before carefully lowering the panel's four feet onto the roof. I also puddled some sealant on top of each exposed stainless bolt head/washer to prevent top down water penetration. If you want to do the belt and suspenders approach, you might just pool Dicor under and over the entire bracket and onto the surrounding roof skin. My current TT is a different brand. I recently bought it used from someone who had paid the dealership to add two 200 watt panels to the roof. That dealership pooled Dicor over each bracket foot.

[whatme]

I went to manufacturer and they were glad enough to take the time to rummage through past files (2007 18FBS) and email a copy.