The permit question, and four federal documents worth knowing

The permit question itself, stated as what it actually is

This site has no source that summarizes local permit-exemption lists, which vary by city and county and are the actual authority here. Ask the local building department whether the job needs a permit, and describe the whole job when you ask — the coating, plus any slab repair, new concrete or change of use.

Code item one: the federal VOC ceiling on the coating itself

Unless otherwise specified, limits are expressed in grams of VOC per liter of coating thinned to the manufacturer's maximum recommendation excluding the volume of any water, exempt compounds, or colorant added to tint bases.

What that changes for your floor The limit that applies follows the category a product is formulated and recommended for. The industrial-maintenance category (450 g/L, the looser ceiling) covers coatings made for extreme conditions in an industrial, commercial or institutional setting, and the federal rule requires such products to carry a label statement such as "For industrial use only" or "Not for residential use." The floor-coating category (400 g/L) names residential flooring directly, so a coating sold for a home floor is likely to fall under that tighter ceiling. The measurement basis quoted above is what either ceiling is actually applied to — the ready-to-use coating, water and exempt compounds already excluded. Several states and air districts set tighter limits than either federal row, so the product label's own compliance claim is worth reading rather than assumed.

Code item two: the federal silica-exposure standard on preparation

The standard sets an exposure limit of 50 micrograms per cubic metre as an eight-hour time-weighted average, and its Table 1 names walk-behind floor grinders and handheld grinders as tasks with specified controls. For a walk-behind floor grinder those controls are integrated water delivery, or a dust collector with a 99-percent filter and a filter-cleaning mechanism plus HEPA vacuuming between passes indoors. For a handheld grinder, water delivery is listed for outdoor work only; indoors the row calls for a shrouded grinder on a dust collector providing at least 25 cubic feet per minute per inch of wheel diameter, plus a respirator once the task runs past four hours in a shift. Shot blasting is not in Table 1: the standard sends abrasive blasting to its exposure-assessment route and to the ventilation standard, 29 CFR 1926.57. The standard binds employers rather than a homeowner working on their own house, but the controls it specifies are the same ones that keep the dust out of a DIY worker's lungs. The dust control page reads the Table 1 rows for a walk-behind floor grinder and a handheld edge grinder.

Code item three: the moisture clause in a federal construction specification

Do not apply epoxies to damp vertical surfaces as determined by ASTM D4263 or horizontal surfaces that exceed 169.0 micrograms moisture per second, square meter 3 lbs of moisture per 1000 square feet in 24 hours as determined by ASTM F1869.

What that changes for your floor This is a federal construction specification, so it binds work built to it rather than residential jobs not built to it, but it is a published numeric ceiling for coating a concrete floor, and the same specification sets the 90-day cure rule for a slab on grade. The same paragraph goes on to tell the reader to follow the manufacturer's recommendations in all cases, so a product data sheet's own limit still has to be checked.

The moisture verdict page runs this comparison against an actual reading and a product's own limit.

Code item four: slip resistance on an accessible route

Accessible floor and ground surfaces must be stable, firm, and slip resistant.

What that changes for your floor Further down the same guide, under "Slip Resistance," it adds that "the standards do not specify a minimum level of slip resistance (coefficient of friction) because a consensus method for rating slip resistance remains elusive." Compliance with the standards is shown by specifying surface materials, textures or finishes that prevent or minimize slipperiness — on this site, a slip-aggregate option in the topcoat (see the finish systems page). A residential garage is not covered by this requirement, but the physics is identical: a glossy cured resin is slipperiest exactly where water and oil land.

What to actually check before starting

• Ask the local building department whether the job needs a permit, describing the whole job — the coating, plus any slab repair, new concrete or change of use.
• Confirm which federal VOC category the product is sold under, and check it against any stricter state or air-district limit.
• If grinding indoors, use each machine's Table 1 controls: water delivery, or a collector with a 99 percent-efficient filter and HEPA clean-down between passes, for a walk-behind grinder; a shrouded grinder on a dust collector for handheld edge work, with a respirator past four hours in a shift. Shot blasting has no Table 1 row, so the employer has to assess exposure instead. See the dust control page.
• Test moisture quantitatively and compare against the product's published limit, not a number repeated from a forum.
• In any commercial or public space, choose a slip-resistant topcoat on accessible routes as a matter of course.