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Securing lumber and building materials on a flatbed: 49 CFR 393.118

Helm PartnersUpdated Oct 30, 2026Sources checked Oct 30, 2026

This guide is general information, not advice on any policy.

Short answer

Under 49 CFR 393.118, bundled lumber, plywood, gypsum board and similar products sit side by side in contact, or are kept from shifting. One tier follows the general securement rules. Two or more tiers need stakes or blocking against side movement plus tiedowns over the top tier, or the spacer rules with extra middle-tier tiedowns. Bundles over 5 feet need at least two tiedowns.

In this guide
  • What the rule covers
  • One tier vs more than one tier
  • Spacers
  • A pre-trip checklist
  • FAQ

What the rule covers

Bundles of dressed lumber, packaged lumber and building products such as plywood or gypsum board (49 CFR 393.118(a)). Unbundled pieces are loose items under the general rules.

One tier vs more than one tier

  • Bundles sit side by side in direct contact, or something keeps them from shifting toward each other.
  • One tier: general rules (393.100 to 393.114).
  • More than one tier, one of these: stakes on the sides plus tiedowns over the top tier; blocking or high-friction devices between tiers plus tiedowns over the top tier; spacers with the middle-tier tiedown rules; or tiedowns over each tier.
  • With 3 tiers on spacers, the middle and top bundles are tied down. With more than 3, one middle bundle and the top bundle are tied down, and that middle tier is no more than 6 feet above the deck, or the second tier from the bottom is tied down.

Spacers

  • Long enough to support every piece in the bottom row of the bundle above.
  • At least as wide as they are tall.
  • Layered spacers fastened so they act as one piece.

A pre-trip checklist

  • Bundles banded and in contact.
  • Tier count and method written on the load sheet.
  • Two or more tiedowns over each top bundle longer than 5 feet (393.110 for general counts).
  • Photos before departure.

Related: flatbed cargo securement and steel coils, heavy equipment securement on a flatbed, flatbed cargo claims and tarp damage, certificates of insurance for mills and plants.

Pipe loads: concrete pipe securement on a flatbed.

FAQ

What counts as a bundle?

Packages of lumber, building materials or similar products unitized for securement as one article. Loose pieces follow the general rules in 393.100 to 393.114.

Does one tier need special rules?

No. One tier follows the general provisions of 393.100 to 393.114.

What are the spacer rules?

Spacers must support all pieces in the bottom row of the bundle above, be at least as wide as they are tall, and act as one piece if made of layers.

How many tiedowns for long bundles?

At least two over the top tier for bundles longer than 1.52 meters (5 feet), under the spacer and each-tier options.

Does a curtain-side or sided trailer change this?

In a sided vehicle or container of adequate strength, the products may be secured under the general rules (393.118(e)).

Does this rule cover logs?

No. Logs have their own rule in 393.116.

This guide is general information, not advice on any policy.

Sources