[Wavery]

I've been using Z brackets held down with 3M VHB tape for years, on many different rigs. 3 different TrailManors, Coleman pop-up (aluminum roof) and 2 different motorhomes (fiberglass Roofs). I've towed for thousands of miles under every weather and wind condition imaginable. With the motorhomes (with large solar panels) I regularly drove 75mph.

In my opinion, if someone had a failure with VHB tape, there must have been an application error. A common error would be improperly preparing a sound surface by not cleaning thoroughly with soap and water, let dry, clean well with 70% rubbing alcohol on the roof AND the Z brackets (to remove manufacturer oils etc).

I would not recommend using VHB tape on a rubber roof or a painted roof (holding power is limited the the holding power of the paint). TrailManor roofs are anodized (not painted) and hold very well when prepared properly.

If you decide to go with thru-bolting the panels with an interior backing plate or large washers, I'd recommend that you install 1" long "crush-sleeves" between the layers of aluminum to prevent smashing the interior Styrofoam.


Well nuts or rivnuts are a better solution than thru-bolting IMO. However, VHB tape (properly installed) has a higher holding power. I just finished helping a friend install a solar panel rack on his Class a motorhome. The 165"x 88" rack sits 12" off of the roof (above the air conditioners) and there are 4, 385W solar panels on it. There are 6, legs with 15" long aluminum feet. Each foot is held to the fiberglass roof with (properly prepped) 1.5" x 15" VHB tape. Each leg has holding power of 1575# x 6, legs = nearly 10,000#.

Besides all that......... a solar panel mounted on the rear roof of the TM, sees very little wind resistance.