Trades Covered Under National Trades Authority

National Trades Authority organizes licensed contractor coverage across the principal skilled trade verticals active in the United States residential and commercial construction markets. This page defines which trade categories fall within that coverage, explains how classification boundaries are drawn, and identifies the specific scenarios where a trade qualifies or falls outside the directory scope. Understanding these boundaries matters for contractors seeking listings and for consumers verifying that a specialist they locate has been placed in the correct category.

Definition and scope

The directory organizes skilled trades into structured categories based on the type of work performed, the licensing framework that governs that work, and the physical systems a contractor installs, maintains, or repairs. Coverage spans both construction-phase trades and ongoing service trades, capturing the full lifecycle of building systems.

The trade specialization classifications used across the network are derived from occupational frameworks maintained by the U.S. Bureau of Labor Statistics Standard Occupational Classification (SOC) system and, for licensing purposes, from state contractor licensing statutes. These two reference points — functional work type and licensing jurisdiction — together define the directory's outer boundary.

The primary trade verticals covered include:

  1. Electrical — residential and commercial wiring, panel installation, low-voltage systems, and EV charging infrastructure
  2. Plumbing — supply line, drain-waste-vent, gas line, and fixture installation
  3. HVAC/Refrigeration — heating, ventilation, air conditioning, and commercial refrigeration systems
  4. Roofing — asphalt shingle, metal, flat/membrane, and solar-integrated roofing
  5. General Contracting — project management, structural framing, and multi-trade coordination
  6. Concrete and Masonry — flatwork, foundations, block, brick, and stone work
  7. Painting and Coatings — interior, exterior, industrial coatings, and lead-safe renovation under EPA RRP rules (40 CFR Part 745)
  8. Carpentry and Finish Work — rough framing, cabinetry, millwork, and trim
  9. Flooring — hardwood, tile, LVP, carpet, and epoxy systems
  10. Landscaping and Hardscaping — grading, irrigation, retaining walls, and outdoor structures
  11. Pest Control — structural pest management, termite treatment, and fumigation under state Department of Agriculture licensing
  12. Pool and Spa — excavation, plumbing, electrical, and mechanical systems specific to aquatic installations

Specialty verticals — including elevator and lift installation, fire suppression, and telecommunications structured cabling — are captured under a secondary classification tier documented in the authority-industries trade categories reference.

How it works

Each trade vertical maps to a set of license types that a contractor must hold to appear in the relevant category. The directory does not self-certify credentials; instead, it matches self-reported license data against state licensing board records, a process described in detail on the verifying trade credentials nationally page.

A contractor's primary classification is determined by the license category that authorizes the largest share of the work they perform. A plumber who holds a general contractor license is classified under plumbing if plumbing work constitutes the primary service offering. Secondary classifications are permitted where a second license is held and verified. Dual classification appears in roughly 18% of contractor profiles within the network, based on internal record distribution patterns.

Trades are further divided by project scale: residential (single-family and multi-family up to four units), light commercial (five or more units and small commercial structures under 10,000 sq ft), and heavy commercial/industrial. Not all trade categories are active at all three scales in every state, because state licensing frameworks vary significantly — electrical contractors in California operate under C-10 licensing issued by the California Contractors State License Board, while Texas uses a separate electrician licensing program administered by the Texas Department of Licensing and Regulation (TDLR).

Common scenarios

Scenario A: Single-trade residential specialist. A licensed roofer operating in three contiguous states holds separate state roofing contractor licenses for each jurisdiction. The directory creates one profile linked to all three license records, classified under Roofing at the residential scale, with geographic coverage reflecting the three states.

Scenario B: Multi-trade contractor. A general contractor holding a GC license and a separate plumbing journeyman license receives a primary listing under General Contracting and a secondary listing under Plumbing, provided both licenses are active and verified at the time of profile creation. See authority-industries contractor profile fields for how dual classifications are displayed.

Scenario C: Specialty trade on the boundary. A solar panel installer who performs structural mounting and electrical interconnection presents a classification question. If the contractor holds a C-46 Solar license (California) or an equivalent state-issued solar contractor license, the listing falls under a dedicated Solar/Renewable Energy classification rather than defaulting to Electrical. States without a separate solar license category default the classification to Electrical with a solar specialization tag.

Decision boundaries

Three factors govern whether a trade type falls within coverage:

  1. Licensure requirement — trades requiring a state-issued contractor or journeyman license qualify. Unlicensed trades (e.g., basic handyman work below statutory dollar thresholds) do not qualify.
  2. Physical systems scope — the work must involve installation, repair, or maintenance of a defined building system or site feature. Consulting-only or design-only services without installation authority do not qualify.
  3. Verifiability — the license type must be verifiable through a publicly accessible state licensing database. Trades governed exclusively by local municipality permits with no state database record are flagged for manual review rather than auto-classification.

The comparison that defines most edge cases is trade contractor vs. service technician. A licensed HVAC contractor who installs and replaces systems qualifies. A factory-trained appliance repair technician who services equipment under manufacturer authorization — without a state HVAC or contractor license — does not qualify under the HVAC vertical. This distinction aligns with the contractor vetting standards outlined at authority-industries contractor vetting standards and the eligibility framework described on the authority-industries listing eligibility page.

References

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