Construction Material Tariff Reference 2026: Every Layer, Rate and Deadline
By Virginia Viadas
There is no single "tariff rate" on construction materials in 2026. Four separate legal authorities operate at once, they stack differently depending on the product, and at least one of them changes again on August 19. This is the reference table — bookmark it, because the answer to "what's the duty on this?" now requires knowing the material, the origin, and which layers apply.
The four active layers
| Authority | What it covers | Rate | Key date |
|---|---|---|---|
| Section 232 | Steel, aluminum, copper (wholly/mostly) | 50% | In effect |
| Section 232 | Derivatives of those metals | 25% | In effect |
| Section 232 | Transformers, panel boards, conduit | 15% | In effect |
| Section 232 | Softwood lumber (derivatives 25%) | 10% | In effect |
| Section 301 | Forced-labor findings, ~60 economies, two tiers | 10% – 12.5% | Effective July 24, 2026 |
| Section 338 | Listed Canadian goods, incl. cement and furniture | 50% | Effective August 19, 2026 |
| Section 122 | Global flat surcharge, all origins | 10% | Expired July 24, 2026 |
Sources: 2026 U.S. Construction Cost Outlook (Section 232 structure); USTR announcement, July 23, 2026; White House proclamations, July 20, 2026. Rates are additional ad valorem duties and may stack with AD/CVD.
The stacking rules that decide your landed cost
Stacking is where most estimates go wrong. Three rules govern it:
- Section 232 takes precedence over Section 338. Each Section 338 proclamation states the new duties do not apply to articles already subject to Section 232 tariffs — no HS code pays both a Section 232 metal duty and Section 338. Globaltradealert
- Section 338 stacks with everything else. The duty stacks on top of other duties including AD/CVD, and USMCA qualification does not exempt a listed good. Customsgenius
- Section 301 and Section 338 interaction is unresolved. Initial CBP guidance does not squarely address whether the two stack — a significant cost question for importers of Canadian goods. Honigman
Carve-outs worth knowing
Energy products, potash, goods already subject to Section 232, fish, and critical minerals are carved out of the Section 338 action. The EU and USMCA partners are largely insulated from the new Section 301 tier structure — which is why sourcing from Mexican industrial corridors is now a live procurement strategy rather than a theoretical one, energy constraints permitting. CustomsgeniusTariffstool
What this does to your material basket
- Tariff impacts range from 5% to 25% depending on material type, with aggregate construction costs estimated to rise roughly 8% under current policy conditions. Our full material cost outlook breaks these down by category.
- Cushman & Wakefield estimated that tariff rates as of April 2026 would raise construction materials costs by 6.0% relative to a 2024 baseline, with total project costs up 3.0%. Cushman & Wakefield
- An AGC-NCCER survey found 43% of general contractors reported at least one project canceled, postponed or scaled back in the past six months because of higher material costs driven by tariffs. HousingWire
That last number is the one to show an owner resisting an escalation clause.
How to use this table on a live bid
- Identify the 8-digit HTSUS subheading, not the product description. Coverage is defined at that level.
- Confirm country of origin from the mill, not the distributor's letterhead.
- Apply Section 232 first; if it applies, Section 338 does not.
- Add Section 301 by origin tier, then AD/CVD where applicable.
- Re-run the calculation after August 19 for anything Canadian.
Duty exposure also depends on getting the specification right in the first place. Over-specifying strength or unit size pulls more tariffed material into the job than the design requires — our concrete strength conversion reference and CMU dimension chart are the fastest way to check that before you order. For properties and comparative cost across the full material set, see the 2026 construction materials guide.
FAQ
What is the tariff on imported steel for construction in 2026?
Steel items made wholly or mostly of steel carry a 50% Section 232 duty; derivative products carry 25%.
What is the tariff on softwood lumber?
10% under Section 232, with derivative wood products at 25%. Additional Canadian-specific duties may apply depending on the product line.
Do tariffs stack on the same product?
Sometimes. Section 338 does not apply where Section 232 already does, but Section 338 stacks with AD/CVD, and the Section 301 interaction is not yet clarified by CBP.
Does USMCA exempt Mexican and Canadian materials?
USMCA partners are largely insulated from the new Section 301 tiers, but USMCA does not exempt goods listed under Section 338.
How much will tariffs add to a typical project?
Estimates range from 3% at the total project level to 6% on materials versus a 2024 baseline, with individual materials varying from 5% to 25%.