# Trailer Floor and Frame Repair > Deck board and full floor replacement, crossmember splicing, rail crack repair and structural reinforcement on commercial trailers. Source: https://fleetservicesocrv.com/services/trailer-and-chassis/trailer-floor-and-frame-repair Business: Fleet Services OCRV, 23281 E La Palma Ave, Yorba Linda, CA 92887 Phone: (714) 909-1844. Serving Santa Ana, California, about 17 miles from the facility. Trailer floor and frame repair replaces rotted or broken decking, renews the fastener pattern, and repairs the crossmembers and main rails that carry the load. Work includes laminated hardwood deck replacement, crossmember splicing and replacement, crack stop drilling, weld repair on structural members, and upper coupler area inspection and reinforcement. ## Specification - Price range: $500 to $9,500 - Labor hours: 4 to 40 hours - Turnaround: Structural - Insurance: commonly billed direct to the carrier ## Symptoms - Soft or springy spots underfoot when walking the deck - Fasteners that back out or will not stay tight in the same boards - Splintering, delamination or visible rot at board ends near the rear frame - Daylight visible through the floor from underneath - Deck sag or a dished appearance in the forward loading area - Visible cracks at the crossmember to rail joints from below - Pallet jack wheels catching or dropping into gaps between boards ## What is a trailer floor actually made of? Standard van trailer decking is laminated hardwood oak, nominally 1-5/16 inch thick, built from thin oak laminations glued into a board rather than sawn from a single plank. The lamination is not a cost shortcut. Glue laminated oak stays dimensionally stable across the humidity swings a trailer sees, while solid sawn plank cups, splits along the grain and works its fasteners loose much faster. Flatbeds and drop decks use a different wood. Apitong, sometimes called keruing, goes down in thicker planks, commonly 1-3/4 inches nominal, because a flatbed deck takes point loads from steel coils, machinery skids and equipment tracks with nothing above it to spread the load. Apitong is dense, oily and durable, and it is worth the price difference on any deck that carries steel. The boards are only half the system. Decking is fastened down into the crossmembers, not simply laid on them, and it is the fastener pattern that lets the floor act as a diaphragm and keep the trailer square. When Santa Ana fleets report a floor that flexes, the boards are frequently fine and the fasteners have simply given up in a section of the trailer that gets loaded the hardest. - Laminated hardwood oak decking at 1-5/16 inch nominal for van trailers - Apitong plank at 1-3/4 inch nominal for flatbed and drop deck service - Self drilling floor screws or floor bolts set through the board into the crossmember - Countersunk heads so a pallet jack wheel never catches a fastener - Board joints staggered so no two seams land on the same crossmember - Butt joints supported directly over a member, never spanning between members ## How do crossmembers fail and how do you fix them? Crossmembers on a standard van trailer are I-beam or hat section members spaced on 12 inch centers through most of the length, tightening to 8 inch centers in the forward section where forklifts drive on and the point loading is worst. They are welded or bolted to the lower flange of the main side rails, and that joint is where fatigue shows up first. Failure comes in three forms. The member itself cracks at the weld toe where it meets the rail, the lower flange of the member tears from a repeated forklift wheel load, or corrosion eats enough section out of a galvanized member that it simply folds. Any of the three lets the floor above it deflect, and once one member goes, the two beside it start carrying its share. Repair depends on how much of the member is gone. A crack gets stop drilled at both ends so it cannot propagate, then the joint is prepped and welded, and a gusset or fishplate goes on where the location sees repeated load. A member with a crushed or corroded midspan gets a splice, meaning the bad section is cut out and a new piece is welded in at both ends. When several adjacent members are gone, full width replacement beats splicing on cost and outcome. One rule never gets bent here. A crack that is simply welded over without stop drilling will reopen in the same place, usually within a season, because the crack tip is still there under the bead. Fleet managers who have paid twice for the same crossmember have usually paid once for a repair that skipped that step. ## When does the main rail or upper coupler area need work? The main side rails are the spine of a van trailer, and their lower flange is where the crossmembers hang. Cracks that start in a crossmember joint can walk into the rail flange, and once they are in the rail the repair stops being a floor job and becomes structural work with fixturing, preheat where the material calls for it, and reinforcement after the weld. The upper coupler assembly at the nose, the plate area and its supporting structure around the kingpin, takes every bit of pull and every shock load the tractor puts into the trailer. Cracked welds around that plate, elongated kingpin bores and buckled nose structure are safety items, not cosmetic ones, and they are the one area on a trailer where a repair decision is never made by eye alone. Slider box rails on a trailer with a repositionable rear group develop their own problems, mainly worn or cracked rail sections, damaged stop plates and bent guide structure from a slider that has been dragged with the pins engaged. Rail section repair and stop plate replacement are in scope. The running gear that rides in that box is not, and it goes back to the fleet maintenance vendor. - Crack stop drilling at both tips before any weld is laid - Fishplate and gusset reinforcement at repeat failure locations - Full penetration splice joints when a member section is replaced - Weld repair on cracked upper coupler plate welds and nose gussets - Slider box rail section repair and stop plate replacement - Bottom flange section replacement where corrosion has removed material ## How do you know the floor needs replacing rather than patching? Sound the floor. A hammer or a heel across the deck tells you where the board has separated from the member, and it maps the problem faster than looking does. Soft spots that group in the forward third usually mean forklift traffic has worked the fasteners and the members under it. Soft spots at the rear doors usually mean water sat there for years. Board replacement works when the failures are scattered and the crossmembers underneath are sound. Individual boards come out, the fastener holes in the members get evaluated, and new board goes in with the joints staggered so no two seams land on the same member. That is a straightforward job and often the right one on a trailer with five good years left. Full deck replacement wins when more than roughly a third of the boards are compromised, when the fastener holes in the members are wallowed out, or when the deck has to come up anyway for crossmember work. Doing it once with a fresh fastener pattern is cheaper than three visits, and it is the only way to get the floor working as a diaphragm again on a trailer that has gone soft overall. ## What does the job cost and how long is the trailer here? Floor and frame work carries the structural turnaround band, 2 to 4 weeks, because decking, welding and refinish sequence rather than run in parallel. Labor bands run 4 to 40 hours and the posted range for the work is roughly 500 dollars for a handful of boards to 9,500 dollars for a full deck with multiple crossmembers and rail repair. Body and structural labor bills at the posted 210 dollar rate. Hardwood decking and structural extrusion are ordered to length, so special order deposits apply, and lead time on apitong in particular can be the longest single item in the job. Santa Ana fleets that plan a floor over a slow quarter get a much better calendar than fleets that discover it in peak season. There is one thing worth doing while the deck is up. With the boards out, the tops of every crossmember are visible and reachable for coating for the only time in that trailer's life. Adding a corrosion treatment line to a floor job costs a fraction of what it would cost as a standalone visit and it is the single best return available on a trailer that is going to stay in a coastal Orange County service area. ## Questions ### How do I know if my trailer floor is going before it fails under a load? Walk it empty and listen. A sound board rings, a separated board thuds. Then get underneath with a light and look at the crossmember to rail joints for rust streaks, which mark cracks that have been working. Fasteners that keep backing out in one area are the third signal. Any two of those three together mean the floor should be scoped before the next heavy season. ### Can I just replace the bad boards instead of the whole floor? Often yes. Board replacement is the right call when the failures are scattered and the crossmembers under them are solid. It stops being the right call when the fastener holes in the members are wallowed out, because new board in a wallowed member will be loose again within months. That is a look underneath, not a guess from the top. ### What is the difference between hardwood and laminated oak flooring? Laminated oak is hardwood, built from thin oak laminations glued into a board rather than sawn as one plank. The laminations cancel out grain movement, so the board stays flat and holds fasteners through humidity swings that would cup and split a solid plank. For van trailers it is the standard for good reason. Solid plank still has a place on some flatbed decks. ### Can a cracked crossmember be welded, or does it have to be replaced? A crack can be welded, provided both crack tips are stop drilled first so they cannot keep running, and provided the member still has its section. If corrosion or a forklift wheel has removed material, a weld over a thin member is a repair with nothing to hold onto. Then the section gets cut out and spliced or the member gets replaced outright. ### My trailer is in Santa Ana and I need it back fast. Can you speed a floor job up? Some. Decking availability and weld sequence set the floor on how fast structural work can go, so 2 to 4 weeks is honest rather than padded. What does help is deciding scope before the trailer arrives. Send photos from underneath and a note on which areas sound soft, and material can be on order before the unit rolls the 17 miles over SR-55 and SR-91. ### Does replacing the floor make the trailer heavier? Slightly, and usually in your favor. New laminated oak weighs close to what the original weighed when it was dry. Old decking that has absorbed years of water can be meaningfully heavier than spec. Fleets that scale a trailer before and after a full deck sometimes find they got payload back rather than gave it up. ### Should I coat the crossmembers while the deck is off? Yes, and it is the best value line item on the whole job. Crossmember tops are unreachable with a floor in place, so this is the one window to prep and coat them. On a trailer working coastal Orange County air, that treatment adds years to the structure at a small fraction of what a standalone corrosion visit would cost later.