How to Put a Diamond Plate on a Trailer Floor

Updated February 21, 2017

Diamond plate, properly called diamond tread plate or checker plate, is a sheet material used for protecting and ornamenting substrates. It is most commonly manufactured from aluminium and used in automotive applications. Users who affix it to trailers typically want to improve skid resistance, reinforce a less-than-sturdy step or ramp, or simply enhance the appearance of their rig. Putting the diamond plate in place on a trailer is a relatively straightforward process, although complex shapes can be time-consuming to produce.

Move the trailer to a space where unobstructed access is available on all sides. Chock the wheels and use the tongue jack to make the chassis approximately level.

Lay sheets of diamond plate on open and unobstructed areas of floor, then use a permanent marker and a straight edge to scribe all necessary cut lines.

Lay panels of diamond plate on the ground close to parts of the trailer that are obstructed by fittings or attachments. Use a tape measure to measure the shapes and sizes of the diamond plate panels required, then transfer the measurements to the diamond plate and scribe the cut marks using a permanent marker and -- as much as possible -- a straight edge. When all the measurements have been transferred and all the lines drawn, recheck every measurement.

Use scissors and flattened-out cardboard boxes or stiff card from a hobby store to make templates of complex shapes. Remake the template as many times as is necessary to create a perfect fit, then trace around the template onto the diamond plate with the permanent marker pen. Ensure the template is right-side-up when transferring the shape.

Working one panel at a time, transfer all panels to an elevated position where a cutting tool can pass through without damaging the supports. Cut out the panels using a jigsaw equipped with a fine-toothed metal blade or an angle grinder equipped with a carbide cutting wheel. Use appropriate protective clothing and eyewear.

Assemble the cut panels into position on the trailer floor. Use the tape measure and the permanent marker to mark a fastener point approximately 1 1/2-inches in from all edges, on every internal and external corner and angle, and approximately once every ten inches along straight lines. Use an electric drill fitted with a 1/32-inch high-speed steel, or HSS, bit to drill pilot holes through both the diamond plate and the trailer floor beneath. Lift away the diamond plate and drill through each hole in the panels again, this time using a bit sized to accommodate the chosen fasteners. Replace the plates.

Working one edge at a time, lift any panel edges that may be subject to moisture intrusion and apply a bead of butyl sealant between the surfaces.

Drive the chosen fasteners through the larger holes in the diamond plate into the pilot holes in the trailer floor beneath.


Choose the fasteners with great care. It is important to consider the phenomenon of electrolytic corrosion. Two different metals, such as steel and aluminium, will eventually corrode each other if placed together, but the phenomena is much more immediate around dissimilar fasteners. Steel screws or rivets driven through aluminium plates will eventually cause holes to form around the screws; the plate will simply fall off. Zinc-plated screws prevent electrolytic corrosion from taking place. For fixing the diamond plate to iron chassis rails, use 1/4-inch #20 self-tapping button-head machine screws. Do not buy screws with countersunk heads; they will not be able to draw into the metal and will therefore remain raised from the plate; this makes cleaning difficult and may damage tires. Use a butyl sealant around rims and edges where moisture entry is predicted to be a problem. Do not use a silicone-based sealant. Silicone outgasses for many months after it is applied, and the gas becomes acetic acid when mixed with water; acetic acid is extremely corrosive to metal.


Despite the tread which gives it its name, diamond plate becomes slippery when wet, especially when wet with oil. Use great caution when walking or driving on wet diamond plate.

Things You'll Need

  • Wheel chocks
  • Permanent marker pen
  • Straight edge
  • Tape measure
  • Protective clothing
  • Jigsaw
  • Angle grinder (optional)
  • Electric drill
  • Drill bits
  • Sealant (optional)
  • Fasteners
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About the Author

John Cagney Nash began composing press releases and event reviews for British nightclubs in 1982. His material was first published in the "Eastern Daily Press." Nash's work focuses on American life, travel and the music industry. In 1998 he earned an OxBridge doctorate in philosophy and immediately emigrated to America.