How to Install Flat Aluminum Siding on a Trailer

Wash the trailer with warm water and several drops of liquid dish soap to remove any dirt, grease or debris from the sides prior to installing aluminum siding. The trailer should be as clean as possible when you begin installation.

Caulk any cracks around the windows and doors of the trailer with a caulk gun before attaching the siding. The trailer surface should be as smooth as possible without any holes or cracks.

Line up the foam board underlay across the side of the trailer and nail it in place. Keep the individual boards as close together as possible as you fasten them so there aren't any gaps.

Nail in the corner posts at each corner of the trailer with a hammer. Each post usually requires two nails to fasten it properly to the trailer's edges.

Draw a chalk line across the bottom of the trailer with the help of a yardstick to ensure you'll have a straight bottom row. Redraw as necessary until the line is straight.

Install the bottom trim onto the trailer by lining it up with the chalk and hammering it into place. Siding gets attached from the bottom first and then you work your way upwards so the trim gives you a starting point for the siding.

Position your F-channel trim under each of the trailer's eaves, which is the overhang where the roof meets the wall. This helps frame the siding appropriately. Then nail J-channel trim in around the doors and windows of the trailer. J-channel trim is usually precut into 12-inch pieces. Cut them down as necessary with a circular saw with a fine-tooth blade. Start at the bottom of the window and then do the sides. Save the top for last. This helps create a tighter seal that prevents leaks.

Position the bottom piece of siding into the footer of the trailer and nail it in place with aluminum roofing nails. Overlap two pieces by at least an inch if you need multiple pieces to complete a row. Cut the pieces with a circular saw to get them the appropriate length. Most aluminum siding kits come with the holes pre-punched in the panels, so you just nail them in place once they are positioned on the trailer.

Interlock the bottom of the next row with the top of the row underneath it and nail it into place. Avoid nailing the panel too tightly into the trailer because the panels need room to expand with temperature changes. Continue adding rows of panels until you reach the top of the trailer.

Slide the top panel under the eave. Trim the panel from the top with the circular saw if it is too wide to fit by itself.

Slide in corner caps around the edges of the siding and nail them in place. The siding is now installed and ready for painting.