Hiring an Epoxy Floor Installer in San Francisco: Licenses, Contracts, Permits

Hiring an epoxy floor installer in San Francisco is a run of checks, each tied to a named rule: the contractor license that the Contractors State License Board (CSLB) administers under California's Business and Professions Code; the home improvement contract and the right to cancel, in that code and in Civil Code sections 1689.5 to 1689.7; permits under the 2025 San Francisco Building Code or, across the county line, each city's own code; the volatile organic compound (VOC) limits in the Bay Area Air District's rule for floor coatings; and the coating's data sheet, which sets the moisture, temperature and cure limits for the slab it goes on. This guide takes them in the order you meet them and ends with the questions to ask before you sign.

Each request from this site is passed to an independent installer nearby, one holding a California contractor license, and the quote and the contract come from that installer. CSLB's fact sheet on online marketplaces says contractor referral services "are legal in California, but within limits," and that a customer should sign with and pay the licensed contractor directly, so the checks below are yours to make. The figures the rules set, such as the license threshold, the down payment cap and the VOC limits, are printed with their sources on the San Francisco floor data page, and published national prices are on the epoxy flooring cost page.

When California Requires a Contractor License for Floor Work

California requires a contractor license for a floor job once its labor and materials together reach the threshold CSLB sets, and at any price once a permit of any kind is involved, or once whoever does the work brings in a helper. CSLB's industry bulletin #24-07, dated December 31, 2024, says Assembly Bill 2622 raised the minor work exemption on January 1, 2025, "but there is a catch: the work cannot require a permit, and the unlicensed person cannot employ anyone for the project." Business and Professions Code section 7048(b) rules out dividing a job into smaller contracts "for the purpose of evasion of this chapter or otherwise," and section 7048(c) takes the exemption away from anyone who advertises as a contractor. The threshold, and the minimum fines CSLB applies from July 1, 2026, are on the floor data page.

Several of CSLB's license classifications describe parts of a floor coating job, and section 7117.6 makes it a cause for discipline for a contractor to advertise and contract for work outside the classification held. In CSLB's definitions, a C-8 Concrete Contractor "forms, pours, places, finishes and installs specified mass, pavement, flat and other concrete work"; a C-15 Flooring and Floor Covering contractor "prepares any surface for the installation of flooring and floor coverings"; a C-33 Painting and Decorating contractor applies paints, stains, fillers and similar materials to decorate and protect surfaces; and under C-61 Limited Specialty, D-6 Concrete-Related Services includes "floor hardening treatment, coloring concrete," while D-12 Synthetic Products includes "resin and epoxy application." CSLB's list also has the B General Building and B-2 Residential Remodeling classes. Ask which classification the license carries and how it covers your floor.

Check the license before you sign. CSLB's Online Services page offers "Check a License or HIS Registration," and CSLB's consumer guidance says to verify a contractor's license online or by calling the Board. The number to look up is on the paperwork: section 7030.5 requires every licensee to put the license number on "all construction contracts," on subcontracts and calls for bid, and in all advertising. A person who sells or negotiates a home improvement contract for a contractor needs, with limited exceptions, a CSLB home improvement salesperson (HIS) registration under sections 7152 and 7154, and section 7159(d) puts that person's name and registration number on the contract. Under section 7027.1, advertising construction work is a misdemeanor for anyone who lacks a license in the classification advertised; section 7027.2 lets an unlicensed person advertise only jobs below the threshold, in ads that say the person is not licensed.

What a California Home Improvement Contract Must Contain

Section 7159 governs the home improvement contract, which it defines as an agreement "whether oral or written" between a contractor and an owner or a tenant once the price passes a figure lower than the license threshold, and section 7159.5 says the contract "shall be in writing." Section 7159(d) lists what it must carry, among them the contractor's name and business address with the license number; the heading "Home Improvement"; the statement "You are entitled to a completely filled in copy of this agreement, signed by both you and the contractor, before any work may be started."; the price; what the project is and which significant materials it uses; when work starts and the estimated completion date; and a note on extra work and change orders. Section 7159(e) adds notices on liability and workers' compensation insurance, a mechanics lien warning and a notice about CSLB.

The materials description is where a floor system belongs: the primer, the base coat, any broadcast (the flake or sand scattered into a wet coat) and the topcoat by product name, plus any moisture treatment. Payments follow section 7159.5. A down payment may not exceed the limit section 7159.5(a)(3) sets, the smaller of a fixed cap and a share of the contract amount, and section 7159(d)(8)(C) makes the contract state that limit. Payments before completion need "a schedule of payments" tied to the work, materials and equipment they cover (section 7159.5(a)(4)), and apart from the down payment "the contractor shall neither request nor accept payment that exceeds the value of the work performed or material delivered" (section 7159.5(a)(5)). CSLB's own advice is shorter: "Don't pay cash, and don't let the payments get ahead of the work."

A home improvement contract signed away from the contractor's place of business can usually be cancelled. Section 7159(e)(6) requires a "Three-Day Right to Cancel" notice, or a "Five-Day Right to Cancel" for a senior citizen, unless the contract falls within the section's exceptions, the first being a contract "Negotiated at the contractor's place of business." The notice lets you cancel "by emailing, mailing, faxing, or delivering a written notice to the contractor at the contractor's place of business by midnight of the third business day after you received a signed and dated copy of the contract that includes this notice," and the contractor must then return what you paid within 10 days. Civil Code section 1689.5 defines a senior citizen as 65 or older, and repair work after a declared emergency carries a seven-day right (section 7159(e)(7)(A)).

Permits: the State Finish-Work List, San Francisco's Code, ADUs

Whether coating a floor needs a permit in San Francisco is a question for the Department of Building Inspection (DBI), because the City's Building Code puts its own administration chapters in place of the state code's. The 2025 California Residential Code (CRC), section R105.2, lists work for which "Permits shall not be required," and its Building item 6 reads "Painting, papering, tiling, carpeting, cabinets, counter tops and similar finish work." The same section warns that an exemption does not authorize work "in violation of the provisions of this code or any other laws or ordinances of this jurisdiction." Chapter 36 of the 2025 San Francisco Building Code says to replace CRC Chapter 1, the chapter that holds section R105.2, "with Chapter 1 & 1A of the San Francisco Building Code." Ask DBI how the City's rules treat a floor coating before the work starts.

A garage turned into a room is a bigger job than a coated garage floor, and SF Planning's accessory dwelling unit (ADU) page sets out the options. It says "Many ADUs are converted from existing storage or garage space," that converted ADUs are "new units created within existing or proposed space in a residential building," and that a Junior ADU can "convert up to 500 square feet of space in a single-family structure." It also says "an ADU may not remove housing services, which includes garage, laundry room, storage space, etc.," and that you "may create living space in your home without creating an ADU," signing an affidavit to "make sure this space won't be used as another residential unit." CSLB's bulletin adds that work "subject to a permit requirement of any kind" needs a contractor license at any price.

Across the county line, the San Mateo County cities each have their own building division, and San Francisco's code does not apply there. South San Francisco's residential handout (revised 02/26) lists "Painting, papering, tiling, carpeting, cabinets, counter tops and similar finish work" among exempt work, and the city's Building Division adds that "electrical, plumbing, or mechanical work must still be permitted" and that owners should check with the Planning Division as well. San Bruno adopts the 2025 California Residential Code in Municipal Code section 11.10.010, and its local amendments in section 11.10.020 do not change section R105.2. In Daly City and Pacifica, ask the city's building division before the work is scheduled.

Bay Area Air Rules for Floor Coatings: Regulation 8, Rule 3

Floor coatings sold and used in the Bay Area fall under the Bay Area Air Quality Management District's Regulation 8, Rule 3, Architectural Coatings, which limits volatile organic compounds in grams of VOC per liter of coating, category by category. The Air District's advisory of September 1, 2011, addressed to the manufacturers, distributors, sellers and users of architectural coatings, says coatings made after the effective dates "must meet the VOC limits below to be sold in the District," and that "Most of the new VOC limits took effect on January 1, 2011"; they are in Table 2 of the rule text dated July 1, 2009. Table 2 lets a floor coating carry a quarter of the VOC permitted under 40 CFR Part 59, Subpart D, the federal standard for the same category; both figures are on the data page.

The label decides the category, and the category decides the limit. Section 8-3-222 of the rule defines a floor coating as "An opaque coating that is labeled and formulated for application to flooring, including, but not limited to, decks, porches, steps, garage floors, and other horizontal surfaces which may be subject to foot traffic." An industrial maintenance coating (section 8-3-226) is a high-performance coating labeled for surfaces, floors included, exposed to extreme conditions such as immersion in chemical solutions, corrosive or acidic agents, temperatures above 250 degrees F or frequent heavy abrasion, and Table 2 allows it more VOC. Concrete and masonry sealers and stains have rows of their own. When a product is recommended for several specialty categories, section 8-3-302.2 decides: "the most restrictive limit shall apply," with the exceptions that section lists.

State building law points the same way. The 2025 CALGreen code (Title 24, Part 11, effective January 1, 2026), residential section 4.504.2.2, says architectural paints and coatings "shall comply with VOC limits in Table 1 of the ARB Architectural Suggested Control Measure," "unless more stringent local limits apply." For your job that comes down to two questions, asked before the products are ordered: what category is each coating on the contract labeled for, and what VOC content does its label or data sheet state? Ask for the data sheets with the quote, so the answers are in writing before anything is mixed.

The Slab: Moisture Tests, Ground-Floor Garages and Bay Fill

Have the slab tested for moisture before a system is chosen, because coating makers name vapor rising through concrete as a cause of blistering and of disbondment, a coating separating from the slab. Sherwin-Williams says disbondment "may result from residual moisture vapor transmission (MVT) through the slab." Three ASTM methods are used. ASTM F1869 sets anhydrous calcium chloride under a sealed dome and reports the moisture vapor emission rate, the pounds of vapor that 1,000 square feet of slab gives off in 24 hours. ASTM F2170 reads relative humidity inside the concrete with in-situ probes placed in drilled holes. ASTM D4263 tapes a plastic sheet to the floor, left in place for at least 16 hours by KTA-Tator's account; it shows that moisture is moving but not how much. Each data sheet names its own test and limit, and the garage floor epoxy page covers them for a garage.

San Francisco's housing puts many slabs on the ground under living space. SF Planning's Sunset District context statement describes the typical house as "a stucco-clad, single-family house, with integrated garage at the ground story and living spaces above," and the Bayview Hunters Point Area Plan says the older housing there "generally consists of one-story dwellings over a garage." Slabs that old may lack a vapor barrier: Stonhard says that with slabs "over 25 years old, there is a risk that a moisture barrier was not installed." One passing test is a snapshot, too. ASTM F1869 says the rate "only reflects the condition of the concrete floor at the time of the test," and Sherwin-Williams says standard epoxy systems are not moisture-tolerant, though formulations and primers made for high vapor drive are available.

The ground under the slab is the other San Francisco question. In Open-File Report 2006-1037, a map report prepared with the California Geological Survey, the U.S. Geological Survey writes that much of the land beside the Bay "is underlain by unconsolidated deposits that are particularly vulnerable to earthquake shaking and liquefaction of water-saturated granular sediment," and that many damage reports from the 1906 and 1989 earthquakes involved older fill "that probably was not engineered." A coating does not hold a moving slab together: Wolverine Coatings' preparation bulletin says "A slab that is crumbling, rocking back and forth, heaving, or sinking is an unlikely candidate for coating without repair," and Sherwin-Williams warns that "Not honoring dynamic joints can lead to cracks in the surface." If the slab has settled or cracked, the concrete resurfacing page covers the repair choices.

What to Ask an Epoxy Installer Before You Sign

Ask for the answers in writing, on the quote or in the contract, so they can be checked later. The data sheets and the rules turn on five points: the moisture test and its reading against the sheet's limit; the concrete surface profile (CSP), meaning how rough the slab is made so the coating can key into it, graded from CSP 1 to CSP 10 in ICRI Guideline 310.2R; the products by name; cure and traffic times, each with the temperature it assumes; and how grinding dust is controlled. One maker's numbers show the range: Sherwin-Williams' Form G-1 lists CSP 5 for that company's flake and quartz broadcast systems and CSP 3 for its metallic topcoat, and a Sherwin-Williams technical article says acid etching is no longer recommended as a preparation method. CSLB's advice adds three steps: "Get three bids, check references, and get a written contract."

Cure times change with temperature, so get them for the temperature your floor will actually see. ArmorSeal 1000 HS, a two-part Sherwin-Williams epoxy, shows the spread: its data sheet's schedule at 50 degrees F reads 48 hours to foot traffic and 10 days to full cure, and at 77 degrees F, 24 hours and 7 days. It is not to be applied below 50 degrees F, and the sheet asks for at least 5 degrees F over the dew point. At NOAA's San Francisco Downtown station, 1991-2020 normals put the January daily low at 46.6 degrees F and the September low at 55.6 degrees F. Those figures describe outdoor air rather than a garage slab, so have both measured on the day. Fast-curing polyaspartics have limits of their own, set out on the polyaspartic floor coating page.

Grinding concrete raises respirable crystalline silica, dust particles federal OSHA describes as "at least 100 times smaller than ordinary sand," and Cal/OSHA's Title 8, section 1532.3 governs the crew's exposure. Its limit is 50 ug/m3 (micrograms per cubic meter), averaged over an 8-hour shift. For walk-behind floor grinders, Table 1 in that section offers a machine with an "integrated water delivery system" or one using the dust collection system its manufacturer recommends, with a filter rated "99% or greater efficiency," and for indoor work it adds: "use a HEPA-filtered vacuum to remove loose dust in between passes." Ask which method will be used in your garage and how the dust will be kept out of the rooms above.

• The license number, the classification it carries, the result of CSLB's license check, and the HIS registration of any salesperson who negotiated the job.
• The moisture test by its ASTM number, the readings and where they were taken, and the limit the coating's data sheet sets.
• The surface profile the system's data sheet asks for, by CSP number, and the method: diamond grinding or shot blasting rather than acid etching.
• Each product by name in the contract's description of significant materials: primer, base coat, broadcast, topcoat and any moisture treatment.
• Recoat, foot traffic, vehicle traffic and full cure times, each with the temperature the data sheet states it at.
• The dust control method from Cal/OSHA's Table 1 for the grinder in use, with HEPA vacuuming between passes indoors.
• The down payment and payment schedule, lien releases on request as payments are made, and the subcontractor information SB 517 lets you request.