For a trailer deck, use 2-inch rough-sawn white oak if you can get it, red oak if you can't, and match the thickness of the boards you're replacing. For board-and-batten barn siding, rough 1-inch boards with narrower battens over the gaps are the standard. For fence boards, rough 1-inch oak or cedar. Rough-sawn lumber is cut to full thickness, so a rough 2-inch board is close to a true 2 inches, not the 1-1/2 inches of a 2x from the lumberyard.
That full thickness, plus a choice of species and lengths you can't find on a store shelf, is why farm and trailer work is some of the most common lumber a local sawmill cuts.
Rough-sawn vs store-bought
Rough-sawn lumber comes straight off the sawmill. It hasn't been planed, so the surface shows saw marks and the dimensions are what the saw cut.
- Thickness is full. Rough 1-inch is about 1 inch thick. Rough 2-inch is about 2 inches. A store 2x6 is planed down to 1-1/2 by 5-1/2.
- Width can be what you need. You aren't limited to standard 2x6, 2x8, 2x10 sizes.
- Lengths can match the job. A trailer bed or barn wall can be sawn to length instead of pieced.
- Species are hardwoods. Most store lumber is pine, fir or spruce. A sawmill cuts oak and other hardwoods, which are harder, heavier and, in white oak's case, more durable outdoors.
- It's usually green. Fresh-sawn lumber is full of water. That's fine for many farm uses, but you need to plan for shrinkage (more below).
Trailer decks
Species. White oak is the classic hardwood for trailer decking. It's hard, stiff and, because its pores are plugged with growths called tyloses, much more resistant to water and rot than red oak. Red oak is strong and hard too, and works as decking, but water soaks into its open pores and it rots faster when it stays wet. Some people use other dense hardwoods. Whatever you choose, avoid softer woods like cottonwood, soft maple or poplar on a deck that carries equipment.
Thickness. Match what the trailer was built for. Many wood-decked trailers come with 2x boards, which are 1-1/2 inches thick, so rough 2-inch hardwood is thicker and stronger than what came on them. If your trailer frame or fasteners were set for 1-1/2-inch boards, a full 2-inch board may need longer bolts or a light planing to fit. Measure an old board before ordering.
Width and length. Measure the deck width across the frame, the number of boards, and whether the outside boards are a different width to fit around stake pockets or rails. Order a few inches of extra length per board so you can trim to an exact fit.
Green or dry? Green oak on a trailer is common and works, but it will shrink in width as it dries. Leave gaps tight at install and expect them to open. Fasten with hardware rated for the job. Oak's tannins corrode plain steel, so use galvanized or stainless fasteners and expect some black staining around them.
Barn siding
Species. Oak is traditional and durable. Eastern red cedar is lighter and naturally rot-resistant, though cedar logs are usually small, so the boards are narrower. Other hardwoods can work for siding with a good overhang to keep rain off.
Thickness. Rough 1-inch boards are the usual siding thickness. They're stiff enough to span between girts and much tougher than thin store siding.
Board and batten. Green boards installed side by side will shrink and leave gaps. Board and batten solves it: nail the wide boards with a small gap between them, then nail narrow battens over each gap. As the boards shrink, the battens keep covering the gaps. Nail each wide board along its center, not both edges, so it can shrink without splitting.
Vertical vs horizontal. Vertical siding sheds water best and is the common barn look. Horizontal board siding with overlapping edges also works.
Fence boards
Species. Oak is the common choice for horse and pasture fence boards: strong, hard to kick through and long-lasting compared with soft woods. White oak outlasts red oak where boards stay wet. Eastern red cedar resists rot and is good for privacy and garden fences, though it's softer.
Thickness and width. Rough 1-inch oak boards in 6-inch and wider widths are a common pasture fence choice. For runs where animals lean or push, thicker boards hold up better.
Posts. Posts in the ground need rot resistance. White oak heartwood and red cedar heartwood are the local hardwood options with real durability. Red oak, ash and soft maple rot quickly in the ground.
Choosing species, in short
| Use | Better choices | Avoid |
|---|---|---|
| Trailer deck | White oak, red oak | Soft maple, cottonwood, poplar |
| Barn siding | Oak, eastern red cedar | Anything without an overhang to protect it |
| Fence boards | Oak, eastern red cedar | Thin store boards on pasture fence |
| Posts in ground | White oak heartwood, cedar heartwood | Red oak, ash, soft maple |
How to sticker and air-dry boards you won't use right away
Siding and fence boards often go up green. If you're holding boards for a while, or want them drier before use, stack them to air-dry the day you get them home. Boards piled flat without spacers mold, stain and warp. The basics, from MU Extension:
- Pick a level, well-drained spot. Build a foundation so the first layer is at least 12 inches off the ground, with supports spaced no more than 24 inches apart.
- Leave a 1- to 2-inch gap between boards in each layer.
- Separate each layer with stickers, commonly 1 inch thick and about 1-1/2 inches wide, straight, dry and lined up directly over the supports.
- Cover the stack with a roof that overhangs by 24 inches on every side, with about 6 inches of air space between the top of the stack and the roof.
- Coat the ends of better boards to slow end checking.
Source: MU Extension G5550, Air-Drying Hardwood Lumber.
A common rule of thumb is roughly a year of air drying per inch of thickness, with warm-season stacking going faster. MU Extension notes that lumber at 15 to 20 percent moisture content is adequate for unheated buildings like garages and barns (G5550).
Ordering
See lumber for what we sell and the pricing page for how lumber is priced by the board foot. To figure board feet for your list, multiply thickness in inches by width in inches by length in feet, and divide by 12. Our board-foot guide walks through it.
Have your own oak log and need decking? We can mill it to your cut list. See custom sawmilling.
Get a Quote
Send us your cut list or your trailer's deck size, the species you want, and when you need it. We'll quote the lumber.