Roof Rack Mounting System

Adjustable System to Mount Solar Panels and More
With Zero Roof Penetrations to Possibly Leak

How we attach the strut to the side of the trailer really depends on the trailer.

The top trim piece that comes with the trailer is screwed to the top of the wall steel members using a #14 x 1-1/4" hex head usually but they vary on where it is on the trim. Sometimes it is low and sometimes centered top to bottom, this will determine if you need a spacer. We reuse the holes already in the trim if centered and no spacer needed.

If a spacer is needed to miss screw heads we use a piece of 1/8" thick x 1-1/2" wide aluminum flat stock.

Use 1-1/4" #14 self tapping hex head screws to attach the strut with 1/4" x 1-1/4" fender washers.

We use butyl tape if we need the aluminum spacer (it goes between spacer and trailer so it fully seals holes) but if no spacer needed to keep strut flat then we use a quality silicone under the fender washer so it is compressed when tightened, we apply the silicone BEFORE inserting hex head, pre-drill if needed. This way silicone is inside the hole and under the fender washer. When tightened it should fill the oval hole in the strut and the fender washer should cover it and seal the penetration.

The shallow strut will bow on spans over 6 feet so only use it on the side of trailer.
Use the 12 gauge deep strut across the top to support panels.

The beauty of the strut system is the ability to add additional features, such as an awning, or privacy shower enclosure as shown in the pictures below. These can be added anywhere on the strut system to meet your needs.

Aluminum vs Steel

Aluminum Unistrut is a light weight alternative to steel Unistrut, however with the reduced self weight comes greatly reduced performance. The Aluminum Unistrut uses a 33% reduction factor for all beam and column loading.

Cost can be a large factor in material choice, depending on where you source aluminum strut the cost can be as much as 4x the cost of galvanized steel strut, if you can source it locally without shipping costs. Standard galvanized steel strut can be easily purchased at Home Depot or Lowes among other local hardware locations.

Mounting Bracket

The mounting bracket is made using a flat plate and "L" bracket. These can be welded or bolted together depending on your situation.
Links to these parts are below under Solar Rack Components
The "L" bracket can also be set at different heights to accommodate a curved roof if need be.

Click on pictures to see full size image

Cable Glands

As you will see in the pictures below, we mount the cable gland so the panels cover it. This is important in snow country to prevent melting snow finding it's way inside. We also prefer to keep all wires covered and out of direct sunlight, even though most solar cable is UV rated, covering helps increase the life of the cables.
Use a bushing for the roof penetration to protect the cables from the metal roof.
Typically we silicone between the gland and roof as we screw it down, then use Dicor self-leveling sealant all around the gland.

Awnings

Mounting an awning or other equipment is very easy as well with this system, the tracks on the commercially available awnings such as you see in the pictures below line up with the holes in the mounting brackets listed. Just bolt them to the awning and bolt to the strut using strut nuts and bolts.
Check clearance on your man door to ensure it clears your awning so the corner of the door does not rip it.