Cargo Trailer Outside Metal
Most factories use sheet aluminum for the exterior. This metal comes in large heavy rolls and are cut at the trailer factory to fit different size trailers.
The metal is attached with sheet metal screws unless screwless installation has been selected by the trailer buyer.
Screwless exterior installation
If the screwless method has been chosen, the exterior side of the wall studs must first be carefully prepared. A chemical is applied to remove oil or other residue and the studs are brushed using a handheld air or electric tool with a wire brush attachment.
Once the wall studs have been prepared, double sided very high bond tape (VHB) is applied to the wall studs. The aluminum panels are then carefully placed into position and then pressed against the tape.
This type of VHB tape works excellent and is very strong, if the preparation has been done properly. If not, the aluminum sheets can come off the trailer while driving down the road.
Screwed exterior installation
Aluminum sheets are cut in sheets and then held in place while screws are inserted from the outside, and into the wall studs. The stud walls can either be tubing, hat-post, or z-post.
To insure that the screws do not miss the wall stud, a chalk line is used as a guide. If the screw misses the wall stud, a hole is left in the exterior aluminum sheet. Although the sheet with the open hole should be replaced, workers often try to hide them by using caulk, or by tilting the screw in the hole just enough to make it go into the wall stud.
In some cases, the hole may be located where trim can be installed over the hole so that it will not be noticed.
Screwless vs screwed
Screwless exteriors provide a smooth and attractive finish. It also makes installation of wraps or decals easier and much better looking. This screwless installation is only for the large external aluminum sheets. The external trim is still fastened using screws.
In addition to appearance, a properly installed screwless exterior will hold up better than screwed exteriors and reduce wrinkling in higher temperatures.
Screws tend to not allow the aluminum sheets to expand and contract from temperature changes, thereby causing it to wrinkle more easily, especially black and other dark colors.
Screws sometimes cause spider cracks to appear over time from the vibration of the trailer.
These cracks often create openings and allow water to seep into the trailer. The holes will continue to expand and cause the sheeting to become loose.
Due to the added work and cost of screwless exterior trailers, many factories only offer screwed exteriors.
Back ramp doors or barn doors, and side doors also get installed while the trailer is in this area. Some factories may wait until the trailer enters the final finish area to install them.
Ramp door
Ramp door with flap/extension