Abstract: A flatbed, step-deck, double-drop deck, or lowboy trailer assembly comprises a plurality of metal crossmembers extending in a transverse direction of the trailer assembly; a metal deck supported by the plurality of crossmembers, the metal deck having an upper deck surface and a lower deck surface; and a pair of parallel wooden boards extending in a longitudinal direction of the trailer assembly proximate respective laterally opposite sides of the trailer assembly. Each wooden board in the pair of wooden boards is located in a respective recessed portion of the metal deck. The lower deck surface is situated between and separates a lower surface of each wooden board from the plurality of metal cross members. The lower deck surface is welded to the plurality of crossmembers.