Warning: A bowed 20-foot deck board is a loaded spring. If it slips out of a pocket while it's bent, it releases along its whole length at once. The creator's own words are that these will rebound and knock you out. Everyone involved stays out of the arc of the board and clear of the ends while it's under tension.
The Problem
The wooden deck boards on a welded flatbed trailer sit in a steel pocket at each end. The boards are cut slightly longer than the clear distance between those pockets, which is what stops them sliding out in service — and what stops a replacement dropping in from above.
There's no easy way around it on a welded trailer. The pockets aren't removable, so the usual approaches are cutting the welds and rebuilding, trimming the board short and screwing it down to every cross member, or fighting it in with blocks under one end.
The Technique
Two people, one board at a time.
- Lay a spare wheel and tyre flat on one of the trailer's cross members, a little toward the tail end of the trailer, so it can roll freely along the frame.
- Feed one end of the new board into its pocket at the far end.
- Lay the board over the top of the wheel. It now sits as a shallow arc, high in the middle, with the free end above its pocket.
- Both people put their weight on the free end until the board bows enough for that end to drop into its pocket. Both ends are now captive and the board is bowed over the wheel.
- Line the ends up in the pockets, then drive the wheel forward out from under the board with a sledgehammer, striking the tyre rather than the board.
- The board flattens into place as the wheel comes out and the wheel drops to the ground under the trailer.
Retrieve the wheel through the open part of the deck and start the next board.
Pro tip: Keep hands flat on top of the board while pushing it down rather than curling fingers under the edge. If the board skips out of the pocket at that moment, anything underneath it goes with it.
Pro tip: The wheel is wider than one board, so the last board in the deck has nowhere to roll. Plan the sequence so the final gap is at an edge you can reach from the side of the trailer, or work from both sides toward a middle board you can lever in with the deck open on both sides of it.
Safety note: Stand to the side when knocking the wheel out, not at either end of the board. Steel-toed boots and eye protection are worth having on: the wheel drops to the ground under the trailer on release, and a sledge striking a tyre at an angle can glance.