Drywall and Insulation Contractors (U.S.) — NAICS 238310

An investor's primer for a general audience — relevant to both public-market and private investors. NAICS (the North American Industry Classification System) is the U.S. government's standard code for industries; 238310 covers the specialty-trade contractors who install building insulation, hang and finish drywall, and do related interior work.

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1. Overview

Drywall and insulation contractors are the crews that turn a building's bare frame into finished, weather-tight rooms. They blow or roll insulation into walls, attics, and floors; they hang gypsum wallboard ("drywall"), then tape, mud, and sand it smooth; and they install acoustical ceilings, firestopping, and soundproofing. They are specialty-trade subcontractors — they almost always work under a homebuilder or general contractor, not directly for the homeowner (remodel work is the exception).[4]

This is a large, essential, deeply cyclical business tied to how many homes and commercial buildings get built and renovated. Two features make it interesting to an investor. First, insulation installers are among the biggest buyers of fiberglass and gypsum, so they earn a spread between the materials they buy and the finished job they sell. Second, the industry is extraordinarily fragmented — roughly 19,600 mostly small, family-owned firms — so a short list of national consolidators has spent years buying up local businesses and compounding value.[2]

Both public and private investors can participate. The public routes are few and specific: a handful of installers, several building-product distributors, and the upstream manufacturers who make the wallboard and insulation. The private routes are the whole long tail — buying, building, or backing a local or regional installation firm. The industry is overwhelmingly private, and the public pure-play list just got shorter: as of July 1, 2026, the largest installer, TopBuild, was absorbed by the distribution roll-up QXO, leaving Installed Building Products as the cleanest independent publicly traded installer.[9][10]

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2. What it is and how it's structured

Scope. NAICS 238310 comprises establishments primarily engaged in drywall, plaster, and building-insulation work.[4] Typical activities: hanging, taping, sanding, texturing, and finishing gypsum wallboard; plastering and lathing; installing acoustical ceiling tile and drop ceilings; soundproofing and firestopping; and installing batt, blown, spray-foam, rigid-board, cellulose, and mineral-wool insulation in attics and wall cavities.[4]

What it excludes (and the adjacent codes). The classification is about installation, not making the materials or doing neighboring trades:

• Making the insulation and wallboard is manufacturing, not contracting — gypsum board and plaster fall under NAICS 327420 (gypsum product manufacturing) and mineral-wool insulation under NAICS 327993.[4]
• Stucco work is NAICS 238140 (masonry contractors).[4]
• Pipe and boiler (mechanical) insulation is NAICS 238290 (other building equipment contractors).[4]
• Neighboring interior trades sit in their own codes: painting and wall covering (238320), flooring (238330), tile and terrazzo (238340), and finish carpentry (part of 2381).[4]
• Selling drywall and insulation through building-material dealers is distribution/retail, not contracting — though, as below, some large companies straddle both installing and distributing.

The value chain. Gypsum and insulation manufacturers → distributors → specialty contractors → builders, general contractors, remodelers, property owners, and public-sector customers. Contractors compete mainly on local relationships, labor availability, scheduling, workmanship, safety, warranty performance, and reliable delivery; large platforms add purchasing power, standardized processes, and acquisition capacity.

Ownership mix. Highly fragmented and mostly private. The average firm books only about $3 million in annual receipts and the average location employs roughly 12 people (derived from the federal counts below).[1][2] At the top sit a small number of national consolidators that grow by buying small installers; everyone else is a local or regional private business, plus many one-person operators and subcontracted crews. Upstream manufacturing is far more concentrated and includes several large family-owned and privately held companies.

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3. How big it is

U.S. federal statistics for NAICS 238310 (dollar figures converted from reported thousands):

(SBA = Small Business Administration — the federal agency whose size standard defines who qualifies as a "small business" for federal programs.)

How concentrated? Barely. The four largest firms account for just 8.6% of revenue, the top eight 11.4%, the top twenty 16.4%, and even the top fifty only 23.2%.[2] The Herfindahl-Hirschman Index (HHI, a standard concentration measure) is suppressed in the federal data for this industry, so we do not state one.[2] For scale, the two biggest national installers' combined installation revenue is only a low-double-digit fraction of the $57.8 billion industry — roughly in line with a top-four share in the high single digits. (Company-reported revenue and Census receipts are not perfectly comparable: the national installers also do distribution and adjacent work that reaches beyond a strict 238310 boundary, which nudges their reported revenue above their classified footprint.)[2][6][8]

Undercount caveat. These figures count employer establishments well but understate the true workforce and activity. County Business Patterns primarily covers businesses with paid employees, and the Economic Census generally excludes nonemployers (businesses with no paid employees, including many self-employed sole proprietors) and government-run establishments.[1][5] Because so much of the labor is subcontracted, seasonal, piece-rate, immigrant, and organized in one-person crews, the ~251,000 payroll employees is best read as a floor, not the full picture.[1][5] Separately, treat the "$500 billion+" market-size figures in some commercial research reports with skepticism — those are global and far broader in scope; the $57.8 billion federal receipts figure is the right U.S. anchor.[2] The ground-truth file contains no clean 238310 operating-margin, backlog, labor-productivity, or nonemployer-receipts measure, so we do not report those.

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4. The investable universe

Very few pure public plays. The table shows the public-market names with meaningful exposure; scale figures are approximate and change with the market. (NYSE = New York Stock Exchange; SEC = Securities and Exchange Commission.)

Upstream material makers (public). Investors wanting exposure to the same construction cycle often buy the manufacturers who supply these contractors: Owens Corning (NYSE: OC) and Carlisle Companies (NYSE: CSL) in insulation, and Saint-Gobain (Euronext Paris: SGO), owner of CertainTeed, in both drywall and insulation.[14][15]

Private and family-owned owners. Much of the supply chain is private:

• Knauf Group — family-owned global manufacturer of drywall, plaster, and insulation; acquired USG (United States Gypsum) in 2019.[16]
• Georgia-Pacific — privately owned by Koch, Inc.; makes gypsum board and other building products.[17]
• National Gypsum — privately held, associated with the Spangler family; sells Gold Bond, ProForm, and PermaBASE.[18]
• ABC Supply / ABC Supply Interiors — private Hendricks-family businesses; ABC Supply Interiors (formerly L&W Supply) distributes wallboard, ceilings, steel framing, and insulation.[19]

The contractor long tail. The bulk of the installation industry is private — thousands of local and regional firms, private-equity-backed roll-ups, and small operators below the radar. They are hard to rank because they trade under local names and often combine drywall, insulation, framing, and firestop work. QXO itself, led by serial acquirer Brad Jacobs, is essentially a public vehicle for private-style consolidation of building-products distribution and installation.[10]

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5. How the money works

This is a specialty-trade contracting business, so the economics are about volume, labor productivity, and the spread on materials — not store counts, subscriptions, or a regulated rate base.

Revenue = jobs won × price per job. Jobs are typically priced by the square footage of wall/ceiling (or by the bag/board installed) plus labor. A contractor buys the insulation and wallboard, marks it up, and charges for installing it — so a large share of revenue is materials passed through at a spread.

Cost structure and margins. The three big costs are materials (gypsum board, fiberglass, spray-foam chemicals), direct labor (crews, often piece-rate or subcontracted), and branch overhead (trucks, warehouses, supervision). Gross margins run roughly 29%–34%: Installed Building Products reported a 33.8% gross margin in 2024, and TopBuild's installation segment about 29%.[7][8] Net margins land in the mid-to-high single digits — IBP earned $256.6 million net on $2.9 billion of revenue in 2024 (~9%).[7]

The levers owners actually pull:

• Labor productivity — boards hung or bags blown per man-hour. Labor is the swing cost, so crew efficiency and low rework make or break a job.
• Price / material pass-through — the ability to raise prices when gypsum and fiberglass costs rise (and hold price when they fall) protects the spread. This is why gross margin, not just revenue, is the number to watch.
• Branch density and route efficiency — clustering jobs near a warehouse cuts drive time and truck cost.
• Mix — commercial and repair/remodel work carry different margins than tract-home new construction.

Fixed-price and working-capital risk. Contractors often bid before final labor and material costs are known, so poor estimating, rework, delays, or unpriced change orders can erase a job's margin. Payroll and job costs are incurred before progress payments are fully collected; retentions, disputed work, and receivables can strain cash.

The consolidator's extra edge. The public roll-ups add a second engine: they buy small installers cheaply (often ~4–6× earnings), then gain purchasing scale (buying fiberglass and board far cheaper than a mom-and-pop can) and cross-sell complementary products through the same crews — gutters, garage doors, firestopping, shower doors, mirrors, closet shelving.[7] It's a capital-light, cash-generative model: IBP produced $340 million of operating cash flow in 2024 and funds dividends, buybacks, and roughly nine acquisitions a year from it.[7]

Useful operating gauges across the chain: housing starts and completions, backlog, revenue per crew or branch, labor cost per installed unit, material-price realization, rework and warranty claims, receivables aging, cash conversion, safety performance, and acquisition returns.

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6. What drives demand

• New residential construction is the biggest single driver. Every new house and apartment needs insulation and drywall — IBP gets roughly 72% of installation revenue from residential new construction — so housing starts (driven by mortgage rates, affordability, and household formation) set the tempo. Note that insulation and drywall work lags starts, because it happens after framing and rough-in.[6][7]
• Commercial and industrial construction — offices, warehouses, and especially data centers, which QXO cited as a strategic reason to buy into insulation at scale.[8][10]
• Repair and remodel (R&R) — a steadier, more recession-resistant demand layer as owners re-insulate and refinish existing buildings.[7]
• Energy codes — the IECC (International Energy Conservation Code), adopted state by state, keeps raising the minimum insulation (measured as R-value, a material's thermal resistance) required in walls and attics. Tougher codes mean more insulation per building — a structural tailwind independent of how many houses get built.[22]
• Policy incentives — the federal 25C Energy Efficient Home Improvement Credit subsidized homeowner insulation upgrades, but the One Big Beautiful Bill Act (OBBBA) ended it on December 31, 2025, removing a retrofit incentive going forward.[24] Affordable-housing provisions such as an expanded Low-Income Housing Tax Credit (LIHTC) could add new-construction demand.[24]

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7. Regulation

Regulation is fragmented across federal, state, and local authorities, and functions as both a compliance cost and a demand driver.

• Building and energy codes. The Department of Energy (DOE) helps develop model energy codes, including the IECC; states and localities then adopt and modify them, so insulation requirements and fire-rated assemblies vary by market. Code tightening raises the minimum insulation contractors must install.[22]
• OSHA respirable crystalline silica standard (Occupational Safety and Health Administration; 29 CFR 1926.1153). Sanding joint compound and cutting board generate silica dust. The permissible exposure limit (PEL) is 50 micrograms per cubic meter of air over an 8-hour day, with an action level of 25; employers need dust controls, a written exposure-control plan, and housekeeping rules (no dry sweeping or compressed-air cleanup that raises dust).[20]
• Other OSHA rules. Fall protection, ladder/scaffold, hazard communication, and respiratory-protection standards all apply on these job sites.[20]
• EPA lead rule. The Environmental Protection Agency's Renovation, Repair and Painting (RRP) Rule governs paid work that disturbs painted surfaces in housing and child-occupied facilities built before 1978; covered firms generally need certification and lead-safe work practices.[21]
• Chemical exposure. Spray polyurethane foam (SPF) insulation involves isocyanates and requires ventilation, training, and personal protective equipment.[23]
• Legacy asbestos. Older insulation can contain asbestos; disturbing it on pre-1980s buildings triggers separate abatement rules and liability.
• Labor and licensing. Many states require a specialty-trade contractor license, plus permits, bonding, and lien rights. The workforce is heavily immigrant, so I-9 / E-Verify employment-eligibility rules and immigration enforcement directly affect labor supply; public and federally funded projects carry Davis-Bacon prevailing-wage requirements.

Larger operators can spread compliance systems across a branch network; small operators may compete on price but carry greater execution and documentation risk.

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8. Competitive dynamics and consolidation

The defining feature is extreme fragmentation with a few national consolidators on top. With a top-four revenue share of just 8.6% and thousands of ~$3-million local firms, barriers to entry are low — a truck, a crew, and a homebuilder relationship.[2] But scale matters where it counts: national players buy materials cheaper, serve big multi-market homebuilders, and standardize safety and back-office costs.

• TopBuild (via its TruTeam installation and Service Partners specialty-distribution arms) was the largest player, at $5.4 billion of 2025 revenue split roughly between installation (~$3.2B) and specialty distribution (~$2.5B), before intercompany eliminations.[8]
• Installed Building Products is #2, at ~$3.0 billion, and runs a steady acquisition machine — roughly nine deals a year.[6][7]
• In April 2026, QXO — Brad Jacobs's building-products distribution roll-up — agreed to buy TopBuild for about $17 billion, closing July 1, 2026. The deal gave QXO the #1 position in North American insulation and more than $18 billion of combined revenue, a sign that financial-sponsor-style consolidation has reached the top of this industry.[9][10]
• In distribution, Home Depot completed its acquisition of GMS (Gypsum Management & Supply) through SRS Distribution in 2025, increasing national scale in wallboard and ceilings even though the underlying contractor market stays locally fragmented.[12]

Upstream, contractors depend on a concentrated set of material makers — Owens Corning and Carlisle in fiberglass; USG (Knauf), Saint-Gobain/CertainTeed, Georgia-Pacific (Koch), and National Gypsum in wallboard — so periodic gypsum-board tightness and price hikes flow straight through to contractor costs.[14][15][16][17][18] The likeliest acquisition targets are profitable regional operators with strong customer relationships, clean payroll and worker-classification records, stable crews, credible job-level margins, and low customer concentration; integration, leverage, culture loss, and antitrust scrutiny are the main constraints.

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9. Risks

• Housing cyclicality. Most revenue rides new construction, so higher mortgage rates or a recession hit volumes hard and fast, and fixed branch costs deleverage on the way down.[8]
• Labor shortage and wage inflation. Skilled-trade labor is scarce and structurally so — drywall installers are among the hardest roles to fill, and their median wages rose roughly 11% recently, faster than construction overall; the sector needs hundreds of thousands of new workers just to keep pace, and 2026 construction forecasts flag severe skilled-trade shortages.[25][26] Immigration policy is a direct swing factor on supply.
• Material cost volatility. Gypsum, fiberglass, and spray-foam chemical prices move, and margins depend on passing increases through — easier in tight markets than in downturns.[8]
• Customer concentration. Large national homebuilders and general contractors can pressure installer pricing, payment terms, and warranty obligations.
• Execution risk. Poor estimating, missed schedules, rework, callbacks, and change-order disputes can turn revenue growth into weak cash returns.
• Safety and liability. Silica and chemical exposure, falls, vehicle accidents, construction-defect and environmental claims, and workers'-compensation costs are real and rising insurance items.[20][21]
• Policy reversal. The expiration of the 25C credit removes a retrofit demand incentive.[24]
• Acquisition/integration risk. Roll-ups can overpay, inherit liabilities, dilute culture, or add debt faster than operations improve as multiples paid rise.
• Measurement risk. Employer-based federal data understate nonemployer and small-crew activity, so top-down sizing is imperfect.[5]

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10. How to invest and the outlook

Public routes — separate the exposures rather than treating them as one bet:

• Direct installers. Installed Building Products (NYSE: IBP) is the cleanest publicly traded pure-play (~$3 billion revenue, ~$5.6 billion market value, still growing by acquisition). Watch installed volume, labor productivity, customer mix, branch economics, and cash generation.[6][11]
• Diversified platforms. QXO (NYSE: QXO) now owns TopBuild and leads North American insulation, but the insulation is diluted within a far larger distribution business — adjust for unrelated segments, acquisition accounting, and leverage.[9][10]
• Distributors and manufacturers. Builders FirstSource (BLDR), Home Depot (HD) via SRS/GMS, and upstream makers Owens Corning (OC), Carlisle (CSL), and Saint-Gobain (SGO) offer exposure to the same construction cycle; focus on volumes, gross margin, utilization, and housing sensitivity.[12][13][14][15]
• Valuation. Compare normalized free cash flow and enterprise value to EBITDA (earnings before interest, taxes, depreciation, and amortization) on cycle-normalized assumptions, not peak-housing earnings. Acquisition-heavy names need extra scrutiny of debt, goodwill, integration costs, and returns on invested capital.

Private routes. This is fundamentally a private-market industry. The realistic ways in are buying or building a local installation firm (SBA-backed acquisition financing fits, given the $19-million small-business threshold), backing or co-investing in a private-equity roll-up, or owning the branch real estate.[3] Because thousands of small firms exist and the top players pay only mid-single-digit earnings multiples, small-installer acquisition remains the core value-creation play — but diligence customer/builder concentration, job-level gross margins and estimating discipline, backlog and retainage, installer retention and worker classification, licensing and safety records, owner dependence, and succession risk.[7]

Near-term outlook (forward-looking judgment). The 2026 setup, on management's own framing, is soft residential demand offset by low-single-digit commercial/industrial growth — data centers a bright spot — with acquisitions filling the gap: TopBuild guided 2026 sales to $5.9–6.2 billion largely on M&A (mergers and acquisitions), and IBP started 2026 with a soft quarter.[8] The swing factors are mortgage rates and housing starts. The structural tailwind is tightening energy codes that mandate more insulation per building; the offsetting headwinds are the loss of the 25C retrofit credit and a labor market that keeps getting tighter and costlier.[22][24][26] Net: a cyclical, cash-generative, consolidating industry where the durable edge belongs to whoever can buy materials cheapest, keep crews productive, and roll up the long tail of small local firms. The most vulnerable operators are the highly leveraged ones dependent on a single builder, with weak labor controls or unpriced material and warranty risk.

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Sources

1. U.S. Census Bureau, "County Business Patterns: 2023 (NAICS 238310)," 2025. https://www.census.gov/data/datasets/2023/econ/cbp/2023-cbp.html
2. U.S. Census Bureau, "2022 Economic Census — Concentration of Largest Firms and Receipts, NAICS 238310," 2025. https://data.census.gov/table/ECNSIZE2022.EC2200SIZECONCEN?q=EC2200SIZECONCEN
3. U.S. Small Business Administration, "Table of Small Business Size Standards (NAICS 238310)," 2023. https://www.sba.gov/document/support-table-size-standards
4. U.S. Census Bureau / NAICS Association, "NAICS 238310 — Drywall and Insulation Contractors (2022 definition and exclusions)." https://www.naics.com/naics-code-description/?code=238310
5. U.S. Census Bureau, "Nonemployer Statistics," 2025. https://www.census.gov/programs-surveys/nonemployer-statistics.html
6. Installed Building Products, Inc., "2025 Form 10-K," 2026. https://www.sec.gov/Archives/edgar/data/1580905/000158090526000004/ibp-20251231.htm
7. Installed Building Products, Inc., "Record Fourth Quarter and Full-Year 2024 Results," 2025. https://investors.installedbuildingproducts.com/news-releases
8. GlobeNewswire / TopBuild Corp., "TopBuild Reports Fourth Quarter and Year-End 2025 Results, Provides 2026 Outlook," 2026. https://www.globenewswire.com/news-release/2026/02/26/3245394/36657/en/topbuild-reports-fourth-quarter-and-year-end-2025-results-provides-2026-outlook.html
9. QXO, Inc., "Form 8-K: Completion of TopBuild Acquisition," 2026. https://www.sec.gov/Archives/edgar/data/1236275/000110465926079864/tm2618991d7_8k.htm
10. HousingWire, "The strategic rationale behind QXO's $17 billion TopBuild acquisition," 2026. https://www.housingwire.com/articles/qxo-topbuild-acquisition/
11. CompaniesMarketCap / Macrotrends, "Installed Building Products market capitalization," 2026. https://companiesmarketcap.com/installed-building-products/marketcap/
12. The Home Depot, Inc., "2025 Annual Report (SRS Distribution / GMS acquisition)," 2026. https://ir.homedepot.com/
13. Builders FirstSource, Inc., "2025 Form 10-K," 2026. https://www.sec.gov/Archives/edgar/data/1316835/000119312526054643/bldr-20251231.htm
14. Owens Corning, "2025 Form 10-K," 2026. https://www.sec.gov/Archives/edgar/data/1370946/000137094626000067/oc-20251231.htm
15. CertainTeed (Saint-Gobain), "CertainTeed Gypsum — company overview," 2021. https://www.certainteed.com/about/
16. Knauf Group, "Our Businesses (USG acquisition, 2019)," 2026. https://www.knauf.com/
17. Georgia-Pacific, "About Us / Building Products," 2026. https://www.gp.com/about-us/
18. Business North Carolina, "National Gypsum's Quiet Style Belies Its Major Role in U.S. Construction," 2025. https://businessnc.com/bnc-125-national-gypsums-quiet-style-belies-its-major-role-in-u-s-construction/
19. Hendricks Holding Company, "About Us (ABC Supply / ABC Supply Interiors, formerly L&W Supply)," 2026. https://www.hendricksholding.com/about-us
20. Occupational Safety and Health Administration (OSHA), "Respirable Crystalline Silica Standard for Construction, 29 CFR 1926.1153; Fall Protection," U.S. Department of Labor. https://www.osha.gov/laws-regs/regulations/standardnumber/1926/1926.1153
21. U.S. Environmental Protection Agency, "Renovation, Repair, and Painting Program: Contractors," 2026. https://www.epa.gov/lead/renovation-repair-and-painting-program-contractors
22. U.S. Department of Energy, "How Are Building Energy Codes Developed? (IECC)," 2016. https://www.energy.gov/scep/building-energy-codes-program
23. U.S. Environmental Protection Agency, "Spray Polyurethane Foam Insulation and How to Use It More Safely." https://archive.epa.gov/epa/saferchoice/spray-polyurethane-foam-spf-insulation-and-how-use-it-more-safely.html
24. Internal Revenue Service, "Energy Efficient Home Improvement Credit (Section 25C) — expiration under the One Big Beautiful Bill Act," 2025. https://www.irs.gov/credits-deductions/energy-efficient-home-improvement-credit
25. Walls & Ceilings, "U.S. Construction Forecast 2026: Modest Growth, Severe Labor Shortages, and Rising Demand for Skilled Trades," 2026. https://www.wconline.com/articles/97954-2026-construction-forecast
26. Home Builders Institute (HBI), "Construction Labor Market Report, Fall 2025," 2025. https://hbi.org/wp-content/uploads/2025/10/Fall-2025-Final-Construction-Labor-Market-Report-Update.pdf