NAICS 423330

Overview

The North American Industry Classification System (NAICS) is the federal standard used to classify business establishments for the purpose of collecting, analyzing, and publishing statistical data about the U.S. economy. Developed under the Office of Management and Budget (OMB) and first adopted in 1997 to replace the SIC system, NAICS is reviewed and updated approximately every five years; most federal statistical programs now use the 2022 structure. ¹

NAICS 423330 covers merchant wholesalers primarily engaged in the distribution of nonwood roofing, nonwood siding, and insulation materials. Establishments that wholesale wood roofing and wood siding are classified in NAICS 423310. Federal statistical programs (e.g., the Economic Census and Annual Wholesale Trade Survey) tabulate data at this industry level. ²

See also on G2X:

• G2X — NAICS 423330 overview
• NAICS 423310 — Lumber, Plywood, Millwork, and Wood Panel Merchant Wholesalers
• NAICS 423390 — Other Construction Material Merchant Wholesalers

What this NAICS covers

• Merchant wholesale distribution of asphalt and metal roofing materials (e.g., shingles, panels, tiles). ²
• Merchant wholesale distribution of nonwood siding materials (e.g., vinyl, fiber-cement, metal). ²
• Merchant wholesale distribution of insulation materials (e.g., fiberglass, foam boards, cellulose). ²
• Merchant wholesale distribution of roofing underlayments and felts. ²
• Merchant wholesale distribution of roof coatings, sealants, and related roof accessories. ²
• Merchant wholesale distribution of flashing and gutter protection products when sold as roofing/siding supplies. ²

Related NAICS and PSC codes

NAICS relationships and cross-references are defined in the U.S. NAICS manual. ²
PSC descriptor is defined in the Product and Service Codes (PSC) Manual. ³

Key exclusions and cross‑references

• Wood roofing and wood siding wholesaling is classified in NAICS 423310, not NAICS 423330. ²
• Construction contractors installing roofing or siding are classified in Sector 23 (e.g., NAICS 238160 and NAICS 238170), not wholesale trade. ⁴
• Wholesaling other construction materials (e.g., manufactured/prefab buildings, flat/plate glass) is generally classified in NAICS 423390 or other specific industries within NAICS 4233. ²

SBA small business size standard (NAICS 423330)

The SBA small business size standard for NAICS 423330 is 225 employees (effective March 17, 2023), as listed in SBA’s Table of Small Business Size Standards. ⁵

Frequently asked questions

• What does NAICS 423330 include?

  • Establishments primarily engaged in merchant wholesale distribution of nonwood roofing, nonwood siding, and insulation materials. Typical products include vinyl siding, metal roofing, asphalt shingles (nonwood), and fiberglass or foam insulation. ²

• Are wood shingles or shakes covered by 423330?

  • No. Wood roofing and wood siding wholesaling is classified in NAICS 423310. NAICS 423330 is limited to nonwood roofing and siding and also includes insulation materials. ²

• Which PSCs commonly pair with 423330 supply buys?

  • PSC 5650 (Roofing and Siding Materials) is common; insulation-focused buys may use PSC 5640 (Wallboard, Building Paper, and Thermal Insulation Materials). PSCs describe the product/service purchased, while NAICS classifies the seller’s industry. ³

• What is the SBA small business size standard for 423330?

  • SBA uses an employee-based standard of 225 employees for NAICS 423330. This threshold governs eligibility for small business programs across agencies unless otherwise specified in a solicitation or regulation. ⁵

Useful resources

• G2X — NAICS 423330 overview
• Census: 2022 NAICS — code 423330 definition and cross‑references. ²
• Census: Implementation of the 2022 NAICS — overview and program adoption timeline. ⁶
• SBA: Table of Small Business Size Standards (effective March 17, 2023). ⁵
• Census: 2022 NAICS Descriptions (reference file). ⁷

References

1. U.S. Census Bureau — North American Industry Classification System (NAICS). https://www.census.gov/naics/
2. U.S. Census Bureau — 2022 NAICS Code 423330: Roofing, Siding, and Insulation Material Merchant Wholesalers. https://www.census.gov/naics/?input=423330&year=2022
3. U.S. General Services Administration — Product and Service Codes (PSC) Manual. https://www.acquisition.gov/psc-manual
4. U.S. Census Bureau — 2022 NAICS Sector 23: Construction. https://www.census.gov/naics/?input=23&year=2022
5. U.S. Small Business Administration — Table of Small Business Size Standards. https://www.sba.gov/document/support-table-size-standards
6. U.S. Census Bureau — The Census Bureau’s Implementation of the 2022 NAICS. https://www.census.gov/programs-surveys/economic-census/guidance/naics/implementation-of-2022-naics.html
7. U.S. Census Bureau — 2022 NAICS Descriptions (download). https://www.census.gov/naics/2022NAICS/2022_NAICS_Descriptions.xlsx