Lumber loads: securing, tarping and booking bundled lumber

Lumber loads are bread-and-butter flatbed freight: bundles of dimensional lumber, plywood, OSB, studs and drywall moving from mills and treaters to distribution yards, building supply stores and job sites. They load fast with a forklift and are usually tarped. The securement rule is short but specific, and 1,976 of the 1,977 lumber securement violations in FMCSA's roadside data for September 2024 to September 2026 were out-of-service (our securement violations analysis has the numbers). Here is the rule, the strap math, tarping, and what to check before you book.

The lumber rule: 49 CFR 393.118

393.118 covers bundles of dressed lumber, packaged lumber and building products such as plywood and gypsum board, plus similar materials. A bundle is a package unitized so it can be secured as one article. Loose, unbundled pieces follow the general rules instead.

Bundle position. Bundles sit side by side in direct contact, or something must keep them from shifting toward each other.

One tier. A single layer of bundles follows the general rules in 393.100 to 393.114: enough tiedowns for each bundle's length and a working load limit total of at least half the weight.

Two or more tiers use one of four methods:

For method 3, spacers have to be long enough to support every piece in the bottom row of the bundle above, at least as wide as they are tall, and multi-layer spacers must be fastened together so they act as one piece.

How many straps: EXAMPLE

EXAMPLE load: 48 ft flatbed, 16 ft bundles loaded two wide, three rows deep and two tiers high, stacked on spacers (method 3). Total cargo weight 44,000 lb. Front row against the headerboard.

• Count rule. Each 16 ft bundle blocked at the front (by the headerboard or the secured row ahead) needs one tiedown per 10 ft or fraction: 2 per row (393.110). Straps over the top tier pass over both bundles side by side, so 3 rows x 2 = 6 straps minimum by count. Method 3 also asks for at least two over each top bundle longer than 5 ft, which the same 6 straps cover.
• WLL rule. Half of 44,000 lb is 22,000 lb. A 4 in strap over the load to the opposite rail counts its full 4,000 lb (393.106(d)): 6 straps give 24,000 lb. Passes.

In practice many drivers run more than the minimum, because bundles settle, straps loosen in rain, and one cut strap should not leave you under the count. Run your numbers through the load securement calculator.

Edge protection goes under every strap where it crosses a bundle edge. Lumber edges crush and cut straps, and protection is required where a tiedown would be cut or worn (393.104). Long v-boards spread the pressure and protect the wood.

Tarping lumber

Most dressed lumber ships tarped to keep it clean and dry; the requirement comes from the shipper or receiver, not the securement rule.

• Tarps. Two 24 x 27 ft lumber tarps with 8 ft drops cover a typical 48 ft deck of lumber. One seller lists the 18 oz version at about 121 lb (Trucking Depot), so lifting them onto the load is real work.
• Smoke tarp on the front stack keeps exhaust off the wood.
• Order: strap first, then tarp, then a second set of tarp straps or bungees to hold the tarp down. Tarp straps never count toward the working load limit.
• Time and safety. Tarping a full lumber load takes time, and wind turns a tarp into a sail. Many shippers have a tarping area; some ban climbing on the load. Our flatbed fall protection guide covers those site rules.

Tarp pay is a separate accessorial negotiated per load. We do not quote a national tarp rate because there is no public source for one; our tarping guide explains how to price it.

Spacers, dunnage and the second tier

• Spacers (often 4 x 4 in) let forks get under each bundle at delivery. They must meet the method 3 size rules when bundles are stacked on them.
• Dunnage on the deck keeps the bottom tier off wet decks and lets the receiver unload by forklift.
• Mixed loads. Different bundle lengths in one load are fine, but each bundle is still counted as its own article, and short bundles at the back can be the ones that walk.

Before you book lumber loads

• Bundle count, lengths and total weight. Lumber can be heavy when wet or treated; keep axle weights legal.
• Tarps required? And which tarps: lumber, smoke, or both.
• Delivery site. Job sites and lumber yards may have no forklift for a second tier or soft ground for the truck.
• Season. Flatbed demand usually rises in spring and summer with construction (Trucking Dive, quoting DAT), and lumber freight follows building activity.
• Where to find it. Mills and treaters ship through brokers and directly; see flatbed load boards for search filters, and flatbed loads for the freight we book. More guides are on the guides page.