A 96-Year-Old Statute Just Repriced Cement, Paint and Plywood

Three proclamations signed July 20 reached past every trade authority normally used, invoking Section 338 of the Tariff Act of 1930 for the first time in the provision's 96-year history. The resulting 50 percent additional ad valorem duty on a listed set of Canadian goods takes effect at 12:01 a.m. Eastern on Saturday, August 22, 2026.

The annexes, published as scanned images, run to hundreds of tariff lines and reach far past the alcohol, dairy and motor vehicle sectors named on the face of the orders. Cement, paint, plywood and fiber cable are all covered. Energy, potash, critical minerals and fish are excluded. The Office of the U.S. Trade Representative puts the covered trade at nearly $20 billion.

The original August 19 start date was suspended Tuesday night with under two hours to spare while Washington and Ottawa work toward an interim agreement. Agencies were ordered to stop collection as soon as practicable, and duty already taken at the border is refundable through standard customs procedure. AGC of America's tariff center, updated August 19, now lists the action as 50 percent effective August 22.

Section 338 is structurally different from the tools the market has learned to price. It requires no injury finding, no public comment period, and carries no sunset. Goods qualifying under the USMCA receive no exemption on the Annex II list.

A carve-out exempts anything already subject to Section 232, which splits the material list in half. Softwood timber and lumber sit at 10 percent under that authority and cabinets and vanities at 25 percent, a rate scheduled to double January 1, 2027. Plywood carries no Section 232 duty at any grade and is listed across nearly the whole of heading 4412. UN COMTRADE recorded $425.5 million of Canadian plywood and veneered panels entering the U.S. in 2025.

Framing lumber is protected. Sheathing plywood is fully exposed. Canada ranks behind Indonesia and Vietnam in hardwood plywood shipped into the United States, and neither of those suppliers is subject to a statute that applies only to Canadian goods.

Implications

Escalation clauses were written for market risk. This is legal risk, and it moves on a signature rather than a curve. Packages priced in July against Canadian suppliers need re-pricing by tariff line, not by wall assembly, because assemblies hide the split. And the domestic substitute will not hold its number: when a tariff redirects demand, U.S. producers of the same product reprice into the gap, a pattern the USITC has documented repeatedly. Commerce is also due to deliver final softwood duty numbers this month, a second August deadline sitting on the same supply chain.