ClearGuard Environmental San Francisco · San Francisco County

Mold testing in San Francisco — from $395, accredited lab result

Mold testing in San Francisco costs $395 and answers two questions with laboratory data: what is growing and how much of it is airborne. Spore-trap air samples and surface samples are read by an accredited laboratory, which matters here because fog-belt Sunset and Richmond ground-floor rooms often show growth with no single leak behind it.

Asbestos · from $425 Mold · from $395 Lead · from $425 Air quality · from $445

Call (415) 592-6414 Instant price check

ClearGuard Environmental San Francisco · 580 California St, Suite 1200, San Francisco, CA 94104 · (415) 592-6414

Instant estimate · about 60 seconds

What your test will cost

What do you need tested?

Choose the concern at this property.

Testing only. We report what the accredited lab finds and never bid the removal or remediation work.

Accredited lab

Third-party analysis

Testing only

No removal sales, ever

Same-day visits

Fast written results

Chain of custody

Tracked from start to finish

What we sample in San Francisco

Indoor spore-trap air cassettes room by room
An outdoor control cassette taken the same hour
Tape-lift samples from visible growth on drywall, trim or tile grout
Bulk samples of wet insulation, carpet pad or subfloor
Cavity air behind suspect walls where a moisture meter reads high
Moisture and relative-humidity readings that explain the counts

Why San Franciscans call us

A visible patch appeared after a roof, window or plumbing leak
A musty smell persists after the area looks dry
A tenant, buyer or insurer asked for documentation
Allergy or asthma symptoms track with time spent in one room
A remediation contractor wants post-work clearance proof

What the written report contains

Spore counts by genus for every indoor sample
Outdoor control comparison so indoor elevation is provable
Moisture and humidity readings per sampled room
Laboratory accreditation, analyst signature and chain of custody

Other tests on the same visit

Asbestos testing — from $425
Lead paint testing — from $425
Indoor air quality testing — from $445

Structured summary

Mold testing in San Francisco — the facts

Mold testing San Francisco service details
Service	Mold testing in San Francisco — sample collection, accredited laboratory analysis and a written result. We never sell removal or remediation.
Price	From $395, laboratory analysis included, quoted before dispatch.
Laboratory method	Spore-trap air cassettes and tape-lift or bulk surface samples, analysed by direct microscopy with genus-level spore counts and an indoor-versus-outdoor comparison
Turnaround	Same-day or next-day collection, written laboratory spore count within 24–48 hours
Coverage	All 34 San Francisco neighbourhoods plus Daly City, South San Francisco, Brisbane and Pacifica.
Rating	5.0 out of 5 from 76 verified customer reviews.
Local office	580 California St, Suite 1200, San Francisco, CA 94104 · (415) 592-6414

The steps

How a San Francisco sampling visit runs

01
Tell us what you're about to disturb
Call, text a photo, or fill out the form. We identify the suspect materials, estimate the sample count, and lock in your flat price before anyone is dispatched.
02
A certified inspector collects the samples safely
Each distinct material is wetted down, a coin-sized piece is cut, sealed, labeled and logged under chain of custody. The mark left behind is smaller than a light-switch plate, and the space is left clean.
03
An accredited lab runs the PLM analysis
Samples are examined by Polarized Light Microscopy with dispersion staining — the EPA-recognized method for bulk building materials — with point counting available for borderline results.
04
You get a written report within 24 hours
A PDF lists every sample location, the analytical method, the fiber type detected and the reported percentage.

Mold testing by San Francisco neighbourhood

The city's building stock changes block by block, so the materials we end up sampling change with it. Each neighbourhood below has its own page with local detail, pricing and booking.

Mold testing in Mission DistrictVictorian and Edwardian flats over ground-floor storefronts, where kitchen remodels usually uncover three layers of flooring above 9-inch tile and black mastic.Mold testing in Noe Valley1900s–1920s single-family Victorians with plaster, lath and original window sash carrying decades of pre-1978 paint.Mold testing in Bernal HeightsSmall pre-war cottages with added-on rear kitchens and basement pipe wrap disturbed by nearly every foundation or garage project.Mold testing in Sunset DistrictRows of 1930s–1950s Sunset homes with fog-belt moisture in ground-floor rooms and stucco, plaster and stacked kitchen flooring above the garage.Mold testing in Richmond District1920s–1940s flats and apartment buildings with plaster walls, boiler-era pipe insulation and layered lead paint on trim.Mold testing in South of MarketConverted warehouses and light-industrial lofts where tenant improvements open textured coatings, mastic and mechanical insulation.Mold testing in CastroOrnate Victorians and Edwardians whose trim stripping and window work regularly raise a lead paint question before an asbestos one.Mold testing in Pacific HeightsLarge pre-war homes and apartment buildings with plaster, decorative trim and original basement heating systems.Mold testing in BayviewPost-war housing and light-industrial buildings, with sprayed ceiling texture in remodelled units and cement-asbestos board on outbuildings.Mold testing in Potrero HillA mix of 1900s cottages and mid-century infill, with hillside garage conversions exposing duct wrap and old flooring.Mold testing in Haight-AshburyDense Victorian flats, repeatedly remodelled, so joint compound, texture coats and stacked flooring can all be in one room.Mold testing in Inner Sunset1920s–1940s homes near the park with plaster interiors and original single-glazed sash in putty.Mold testing in Outer SunsetCoastal fog and closed garages keep ground-floor rooms damp, which is why mold and air quality calls here often have no single leak.Mold testing in Inner RichmondPre-war flats above retail, where commercial tenant work and residential remodels disturb the same plaster and mastic.Mold testing in Outer Richmond1930s–1950s homes with stucco exteriors, plaster interiors and long drying times in north-facing rooms.Mold testing in Marina District1920s–1930s stucco homes and apartments built on fill, with original heating runs and post-1989 repair layers.Mold testing in North BeachOlder apartment buildings and flats with boiler-era insulation, plaster and heavy paint layering on stairwells and trim.Mold testing in Russian HillPre-war apartment stock where unit turnovers open plaster, mastic and mechanical chases in shared basements.Mold testing in Nob HillDense early-1900s buildings with decorative plaster, old pipe insulation and repainted corridors.Mold testing in Hayes ValleyVictorian flats and small apartment buildings where post-freeway infill sits beside untouched pre-war interiors.Mold testing in Glen Park1920s–1940s cottages on steep lots, with crawl-space ducting and stacked kitchen flooring.Mold testing in Twin PeaksMid-century homes with sprayed ceiling texture, sheet flooring and original furnace ducting.Mold testing in West Portal1920s–1930s tunnel-era homes with plaster, lead-painted trim and garage-level utility runs.Mold testing in ParksidePost-war Sunset-adjacent tracts with sprayed ceiling texture and 9-inch tile still under later flooring.Mold testing in LakeshoreMid-century homes and apartment blocks near the lake with original ducting and resilient flooring.Mold testing in Presidio HeightsLarge pre-war houses with elaborate plaster, deep paint layering and basement mechanical rooms.Mold testing in Mission BayNewer construction where the questions are usually indoor air quality and moisture rather than legacy material.Mold testing in DogpatchIndustrial conversions and worker cottages side by side, so one block can hold both textured coatings and Victorian plaster.Mold testing in Excelsior1920s–1950s homes with stucco, plaster and stacked flooring, and heavy DIY remodel history.Mold testing in PortolaPost-war single-family homes with sprayed ceilings, 9-inch tile and original crawl-space ducting.Mold testing in OceanviewMixed pre-war and post-war stock with layered paint, textured ceilings and moisture in ground-floor rooms.Mold testing in Ingleside1920s–1940s homes with plaster, lead-painted sash and old floor tile under carpet.Mold testing in Visitacion ValleyPost-war housing where remodels and unit turnovers regularly reveal texture, tile and mastic.Mold testing in Treasure IslandFormer naval housing and commercial buildings where legacy material is the working assumption before any work.

Just over the county line

Daly City South San Francisco Brisbane Pacifica

Independence

A company should not test the material it hopes to remove.

We collect and test material. ClearGuard does not sell removal work, keeping the finding independent. An abatement crew offering a "free inspection" is running a sales call with a lab form attached. We only sell the test, so a clean result and a positive result pay us exactly the same.

No removal bids, no upsell, no referral kickback
Every sample goes to an independent, accredited laboratory
You get material names and percentages, not a vague pass or fail
If a result is positive, we point you to licensed local abatement crews and exit the job

FAQ

Mold testing in San Francisco — questions

How much does mold testing cost in San Francisco?

$395, laboratory analysis included, quoted before anyone is dispatched. Optional 4–8 hour expedited handling adds $99.

How fast can a sampler reach a San Francisco address?

Usually the same day for requests placed early, otherwise the next morning. Our San Francisco office at 580 California St, Suite 1200 runs daily routes through every neighbourhood, and the written accredited result follows within 24 hours.

Which San Francisco neighbourhoods do you cover?

All of them — from the Outer Sunset and Outer Richmond through the Mission, Castro, SoMa, Bayview and Visitacion Valley, plus Daly City, South San Francisco, Brisbane and Pacifica just over the line.

Do you also do the removal or remediation work?

No, and that is deliberate. ClearGuard only collects samples and reports laboratory results, so the finding is never attached to a removal sale. If work is needed, you take our report to any licensed contractor you choose.

Can you test an occupied flat or a rent-controlled building?

Yes. Sampling is wet-method and contained, every point is photographed and patched before the sampler leaves, and visits are scheduled around tenant notice periods.

What do I get at the end?

A written accredited laboratory report with sample locations, photographs, the method used and a plain-language result you can hand to a contractor, a landlord, a buyer or an insurer. We provide the test and the report — not permits, surveys or removal scopes.

How much does mold testing cost?

Mold testing starts at $395, which covers the visit, one indoor spore-trap sample, the outdoor control and the laboratory spore count. Additional rooms or surface samples are quoted before the visit.

Is a mold test worth it if I can already see the growth?

Yes, for two reasons: the lab identifies the genus, which changes how the cleanup is handled, and an air sample shows whether spores have spread beyond the visible patch into rooms that look clean.

Do you do mold remediation too?

No. We test and report only. A remediation company will read our numbers, but it will never be us selling you the cleanup.

Before you start work

California pre-renovation asbestos rules, explainedWhat NESHAP, BAAQMD Regulation 11 Rule 2 and Cal/OSHA actually ask for before you open a wall.California pre-renovation lead paint rules, explainedThe EPA RRP rule and California Title 17 in plain language, for any building painted before 1978.