I want to add a tie to the outside of my trailer, it is skinned on the inside and out therefore I can't really tell where the ribs are, would it be safe to assume the rivets that hold the siding on the trailer go through the ribs?

Mike

Thanks Gard...is it as simple as getting the drill out and putting a couple of holes in the trailer?

Mike

The wall studs can be anywhere from 1 1/2" to 4" wide depending on the manufacturer and where the stud is located. Some studs are tubular, some are "C" shaped and others can be hat shaped. Regardless of the type, it is important to drill the holes through the middle of the stud. If you use the plastic handle of a  screwdriver, taping on the metal siding near the rivets, you will be able by sound, to determine the edges of the stud. Using a marker or tape, delineate the edges, measure to the center and mark the holes using the tie ring as a template.

As PH suggested, a backing plate will spread the stresses out a bit. If that is not available, large stainless automotive skin washers will help. Use self locking nuts on the bolts instead of locking washers. Don't over tighten the bolts or you can crush the studs.