Countertop Fabrication Shop Deductions: The CNC, the Bridge Saw, the Slab Inventory, and the Silica Compliance OSHA Requires

Countertop fabrication sits between manufacturing and installation, and its tax picture is heavier on both sides than the cabinet shop's. The shop equipment — the largest line: the CNC router or CNC saw-jet (a six-figure machine in many shops), the bridge saw, the edge polisher and profiling machines, the water recycling and filtration system (required by the wet-cutting the silica rules push toward), the overhead crane or gantry and the slab racks, the forklift and the slab-handling equipment (the A-frames, the vacuum lifters), the digital templating system (the laser or photo templating hardware and software), the dust collection and the wet-processing infrastructure, and the hand tools (grinders, polishers, seam-setting equipment) — recovered by section 179 expensing (income-limited; the annual limit US$2,560,000 for 2026, phasing out above US$4,090,000 of purchases, raised and made permanent by the 2025 law), bonus depreciation (restored to 100% and permanent for property acquired after January 19, 2025; no income limit), or MACRS over seven years for most fabrication machinery (five for some), with the election made asset by asset on the first return after purchase; a shop buying a CNC in a profitable year expenses it; a shop opening with US$400,000 of equipment and little first-year income takes bonus depreciation for the loss (used within the excess business loss limitation) or spreads it — the choice depends on the owner's other income and the shop's trajectory. The de minimis safe harbor: the consumables and small tools — blades, bits, polishing pads, adhesives, seam-setting supplies, the shop's safety gear — expensed under the annual election below the US$2,500 per-invoice threshold. The slab inventory — the trade's distinctive accounting: unlike the cabinet shop's sheet goods (bought per job, mostly), a countertop shop stocks slabs — granite, quartz, quartzite, marble, porcelain — bought from distributors by the slab or the bundle, held on racks until a job calls for them, with remnants from every job accumulating as saleable inventory for smaller pieces (vanities, backsplashes); the slabs are inventory: a shop under the small-business gross-receipts threshold may treat inventory as non-incidental materials and supplies (deducted when used or consumed) or conform to its book method — but a shop with US$100,000 of slabs on the rack has a year-end count that matters (the deduction for slabs consumed follows the jobs; the slabs on the rack at year-end are not yet deductible under either method), and the remnant inventory is tracked at cost (or written down where a remnant has no realistic sale — the shop's remnant policy is a tax position as well as a business one); the job-cost system codes each slab to the job it was cut for, with the remnant returned to inventory at its allocated cost, and the year-end count reconciles the rack to the books — the count that, skipped, makes the shop's cost of goods sold a guess. Materials that aren't inventory: the sink cutouts' sinks (bought per job), the adhesives and sealers (supplies), and the install materials — job costs expensed as consumed. The silica compliance — the trade's regulatory cost: OSHA's respirable crystalline silica standard for general industry applies to countertop fabrication with force — engineered stone's silica content makes it the trade the standard was tightened for — and compliance costs are real: the wet-cutting equipment and the water recycling (equipment, depreciated or expensed), the ventilation and dust collection (equipment), the respirators and fit testing (supplies and services), the medical surveillance the standard requires for exposed workers (a recurring cost — deductible as ordinary), the exposure monitoring and the written exposure control plan (consulting and testing fees — deductible), the training (deductible), and — in states that have gone further (California's Cal/OSHA engineered-stone standard and similar rules in other states) — the additional compliance the state imposes; every dollar is deductible, and the equipment portion follows the depreciation elections; a shop that skips compliance carries a liability (the citations, and the silicosis claims that are reshaping the industry) that no deduction offsets. The install side: the install trucks or vans (heavy vehicles carrying slabs — actual expenses, with section 179 or bonus on purchase; the A-frame racks on the trucks as equipment), the install crew's tools (de minimis), the mileage log, and the install labor (employees on payroll with workers' compensation at the trade's rate — heavy lifting and cutting — or genuine subcontractors with W-9s and 1099s where the installer has their own business; the classification guides). The shop space: rented (rent, with the shop's improvements — the water and drainage infrastructure, the crane's structural supports — analyzed as qualified improvement property or over the building's life) or owned (thirty-nine years, with the land improvements at fifteen and a cost segregation analysis on a purchased building for the specialized components). Labor: fabricators, polishers, templaters, and installers on payroll with workers' compensation (the trade's injury profile — cuts, lifting, silica — prices it), the shop's safety officer role, and the classification question for any "contractor" who works only in this shop on its schedule with its machines (an employee). Other deductions: the digital templating and shop software (subscriptions), the fabrication software's licenses, insurance (general liability with completed operations — a cracked slab after install is a claim; the shop's property and equipment coverage; the trucks' commercial policies), the slab distributors' delivery charges (job costs or inventory cost), the disposal of stone waste (a job cost — heavy and priced by the ton), utilities (the shop's water and power — the water recycling reduces the water bill and is itself equipment), marketing (the showroom's samples — display material, not inventory; the kitchen and bath dealer relationships), and professional fees. Sales tax: installed countertops follow the construction sales tax guide's state rules (the consumer rule in most states — tax paid on the slabs at purchase, none charged on the installed job; the retailer rule in a few); slabs and remnants sold uninstalled (to a contractor or a homeowner) are retail sales with tax collected; and a shop that also sells sinks and faucets uninstalled is a retailer of those. Entity and self-employment: countertop fabrication is not a specified service trade, so the qualified business income deduction applies at all income levels (subject to the wage-and-property limitation, satisfied many times over by a shop with payroll and a CNC); the S election arithmetic (the countertop entity guide) runs on profit above a reasonable salary for a working owner-fabricator — and the shop's large unadjusted basis in equipment supports the QBI limitation's property component long after the equipment is fully depreciated. The bookkeeping: a fixed asset schedule (every machine with method and life — the largest schedule in the installation trades), the de minimis election annually, slab inventory by slab with job coding and the remnant policy, the year-end rack count, silica compliance as a tracked line (equipment vs recurring), payroll and classification, the install trucks, sales tax by sale type, and the job cost report that shows the shop which stone types and which dealer relationships make money. The errors: slabs on the rack expensed at purchase (a cost of goods sold that runs ahead of the jobs, and a year-end count that doesn't exist); remnants carried at zero or not at all (an inventory that walks out the door as vanity tops with no cost against them); the CNC depreciated over seven years in a year that could have expensed it; the water recycling system treated as a utility cost; and the silica compliance skipped as an expense that "doesn't make money."

Key takeaways

• The fabrication equipment is the largest schedule in the installation trades: CNC, bridge saw, polishers, water recycling, crane, forklift, templating — section 179 (income-limited), bonus depreciation (no limit; loss within the excess business loss limitation), or seven-year MACRS, asset by asset.
• Slabs are real inventory: coded to jobs when cut, remnants returned to inventory at allocated cost, a year-end rack count that reconciles to the books — expensed as consumed under the small-business method, never at purchase; the remnant policy is a tax position.
• Silica compliance is a required, deductible cost: wet-cutting and water recycling (equipment), ventilation, respirators and fit testing, medical surveillance, exposure monitoring, the written plan, training — and state engineered-stone rules where they apply.
• Install trucks on actual expenses (heavy vehicles, section 179 or bonus on purchase); installers on payroll with workers' comp at the trade's rate, or genuine subcontractors.
• Sales tax: installed countertops under the state's construction rule (consumer rule in most states); uninstalled slabs, remnants, sinks, and faucets are retail sales with tax collected.
• Not a specified service trade; the equipment's unadjusted basis supports the QBI limitation long after it's depreciated.

The countertop shop's year-end file

Fixed asset schedule: every machine, method, life; new purchases with the 179/bonus/MACRS decision. De minimis election; consumables receipted. Inventory: slabs by slab with job coding; remnants at allocated cost; the year-end rack count; the remnant write-down policy. Silica compliance: equipment on the schedule; recurring costs tracked. Trucks: method, log. Payroll, workers' comp, classification; subcontractor W-9s and 1099s. Shop: rent or building with improvements classified. Insurance (completed operations), software, disposal, utilities, marketing (samples as display). Sales tax by sale type. The rack count and the schedule are the two items a preparer cannot build in April.

Worked example

A fabrication shop grosses US$1.9 million: US$720,000 of slabs and materials, twelve employees, a rented shop, and this year's purchases — a CNC saw-jet (US$285,000) and a water recycling system (US$48,000). Equipment: the saw-jet and the recycling system expensed under bonus depreciation (the shop is profitable; the write-off doesn't create a loss); blades, bits, pads, and safety gear (US$21,000 across many invoices) expensed under the de minimis election; the bridge saw and polishers bought in prior years on the schedule on their seven-year lives. Inventory: 240 slabs bought during the year, each coded to a job when cut with the remnant returned to inventory at allocated cost; the December rack count — 38 full slabs (US$62,000) and remnants (US$14,000 at allocated cost after a write-down of pieces too small to sell) — reconciled to the books; cost of goods sold is the slabs consumed, not the slabs bought. Silica: the recycling system and the ventilation upgrade (equipment); respirators, fit testing, exposure monitoring, the medical surveillance for nine exposed workers, and the written plan's consultant (US$19,000 of recurring compliance — deductible); the state's engineered-stone rules met. Install: two heavy trucks with A-frames on actual expenses; four installers on payroll with workers' compensation at the fabrication trade's rate; a seam-setting subcontractor with his own business (a W-9 and a 1099). Sales tax: installed jobs under the consumer rule (tax paid on slabs at purchase); US$41,000 of uninstalled remnant and slab sales to contractors as retail sales with tax collected. Net profit after the equipment write-offs lands in the mid six figures — an S corporation with the owner's salary set from market data for a working shop manager-fabricator, the QBI deduction applying in full with the equipment's basis supporting the limitation. The prior owner's returns had expensed slabs at purchase (cost of goods sold running US$80,000 ahead of the jobs in a growth year), carried remnants at zero, and booked the water recycling as a utility — three errors the rack count and the schedule replaced.

Official sources

Publication 946 states that "this publication explains how you can recover the cost of business or income-producing property through deductions for depreciation (for example, the special depreciation allowance and deductions under the Modified Accelerated Cost Recovery System (MACRS))," and covers the section 179 election and its limits. — Internal Revenue Service, Publication 946, How To Depreciate Property, https://www.irs.gov/publications/p946

The IRS states that under the de minimis safe harbor, "if you don't have an applicable financial statement (AFS), you may use the safe harbor to deduct amounts up to $2,500 ($500 prior to Jan. 1, 2016) per invoice or item (as substantiated by invoice)," with the election made annually on a timely filed return. — Internal Revenue Service, Tangible property final regulations, https://www.irs.gov/businesses/small-businesses-self-employed/tangible-property-final-regulations

Practitioner note

A countertop shop is a manufacturer's depreciation schedule with a stone yard attached, and the two errors we inherit most are slabs expensed at purchase and remnants carried at nothing — a cost of goods sold that runs ahead of the jobs and an inventory that walks out the door as vanity tops with no cost against them. Our fabrication files code every slab to its job, count the rack in December, put the water recycling on the schedule as the equipment the silica rules made it, and track the compliance line the industry's silicosis claims have made non-optional.

See also: For related guidance, see the countertop fabrication entity decision; and browse every small business tax guide, by situation.

Next step

Fairlight handles countertop fabrication returns and bookkeeping — equipment depreciation elections and the fixed asset schedule, slab and remnant inventory with job coding and year-end counts, silica compliance cost treatment, install truck and crew classification, and sales tax by sale type. See pricing or book a call.