Mold inspection and house mould testing in London, before anyone sells you a cure.
Reviewed October 2026 · London, Ontario
A mold inspection with lab-tested samples costs $300 to $600 in London, results take two to three business days, and we never sell removal. Independent mold testing in London, Ontario, with prices on the mold inspection cost page and a plain guide to mould removal in London, Ontario if you ever need it. We sample, an accredited lab identifies it, and you get a plain-language report. Whether you need removal, and how much, is your call, made on evidence instead of a sales pitch.
Most homes we test come back normal. That's a good day, and you spent a few hundred dollars to know it.
The company that inspects your home for free and then quotes you thousands to fix it has one incentive, and it isn't you. We sell testing only. The result is the result.
Every mold question the market answers with a sales quote.
The full set: inspections, accredited-lab testing, and the guides that tell you whether you even need us. No gates, no scare tactics.
Testing & inspection
Mold inspection
A full walk-through, moisture readings, and a sampling plan, so nothing is missed and nothing is invented.
→Black mold testing
The question most people call about. We identify what the dark growth actually is, because the eye cannot.
→Air & surface testing
Air, tape, swab and bulk sampling, analyzed at an accredited lab with a documented chain of custody.
→Indoor air quality
Airborne spore counts measured against an outdoor baseline, for the symptoms you feel but cannot see.
→Attic mold
The cold-roof and bath-fan condensation problem London attics get over a winter, checked properly.
→Basement mold
London’s older basements and spring flooding make this the most common inspection we run.
→Clearance testing
Independent proof the removal actually worked, before you pay the final invoice or move back in.
→Guides & decisions
Hiring for mold removal
We do not remove mold. How to size the job, check older homes for asbestos, and compare quotes on one scope.
→What it costs
$300 to $600 for a residential inspection with lab sampling, published up front. Almost nobody here does.
→Do I need a test?
A two-minute triage. Tell us the situation and get a straight answer on whether testing makes sense.
→Is black mold dangerous?
The honest health framing: what only a lab can tell you, and what belongs with your doctor.
→Test kit vs pro
What a $30 hardware-store kit can and cannot actually tell you about your home.
→Buying a house with mold
What a spot on the inspection report means, and how to test before you waive your conditions.
→Landlord & tenant
Who is responsible, the escalation ladder, and the third-party document that ends the standoff.
→Asbestos survey & testing
The asbestos survey a pre-1990 London home needs before a renovation, a demolition or mould removal cuts into old materials.
→In this city, it's almost always a moisture story.
The homes we test across London share a few patterns, and nearly all of them trace back to water getting somewhere it shouldn't and staying.
- The century houses of Old North and Old South, with stone-and-brick foundations and original basements that were never built to stay dry.
- Spring melt and Thames-area flooding, which soak basements most years. Drying the space stops new growth but never tells you what already grew, which is why a clearance test exists.
- Cold-roof attics where a bathroom fan vents into the attic instead of outside, so a winter of condensation feeds mold on the sheathing. That is the attic inspection in a sentence.
- The large student-rental stock around Western University and Fanshawe College: converted houses, absentee owners, and the landlord-tenant standoff that mold so often becomes.
Under London's Property Standards By-law CP-24 and Residential Rental Units Licensing By-law CP-19, a rental has to be kept in good repair and free of mold, and a tenant can report a rental concern to the City. When it comes to that, an independent test is the document that settles who is right. Our landlord and tenant guide walks the whole escalation ladder.
The real situations, in the words people use.
Dark growth is common and is not automatically toxic. We identify what it is; your doctor is the right person for symptoms. Testing replaces the fear with a fact.
London's older basements and spring flooding make this the most common call. Drying stops new growth; it doesn't tell you what already grew. A clearance test does.
In a student-rental city, mold is where landlords and tenants stall. An independent third-party test is the document that ends the standoff.
Then don't get one. Get a test from someone with nothing to sell but the test.
A test is not how you decide whether mold is bad.
Health Canada's guidance is plain: any significant indoor mold should be removed and the moisture behind it fixed, whatever the type, and health symptoms are a question for your physician rather than a lab. So testing is not how you decide whether mold is a problem. It is how you get four things a free contractor inspection cannot give you:
- Documentation. An accredited-lab result with a chain of custody, not a salesperson's opinion of a stain.
- A real-estate answer. What a spot on the inspection report actually is, before you waive your conditions.
- A dispute settled. The third-party evidence a landlord or tenant needs when one side says it's fine.
- Clearance. Independent proof that a remediation actually worked, before the final invoice is paid.
We identify what is present and measure it against the outdoor baseline that day. Because we do not remediate, there is nothing we gain by finding a problem that isn't there. That independence is the whole product. For the health framing itself, the US EPA's mold and health page and Health Canada agree on the essentials: fix the water, remove the growth, and take symptoms to a doctor.
What house mould testing actually involves.
House mould testing is not a kit on the counter and not a free look from a removal company. It is three things done in order: find the moisture, sample where the evidence points, and let an accredited lab name what is there.
- Moisture first. A meter finds damp drywall, framing and slab edges before mould is visible, which is where the next problem starts.
- Surface samples (tape lift or swab) identify a visible patch, so a dark mark gets a name instead of an adjective.
- Air samples compare indoor spore levels with an outdoor sample taken the same day. That shows whether the air inside is elevated against outside. It does not set a health threshold: Health Canada says there is no "safe" limit for mould because people differ so much, which is why symptoms go to your doctor.
A two-minute mold check you can do first
Before you call anyone, walk the house with a flashlight and your nose. Look at basement walls and the floor edges, under the kitchen and bathroom sinks, around window frames, the bathroom ceiling, and the attic sheathing near where the bath fan runs. Note anywhere that has leaked before. If you find a small patch with an obvious cause, Health Canada's advice is to clean it and fix the moisture, and you may never need us. If you smell must with nothing to see, the growth keeps coming back, or someone else needs a document, that is when testing pays for itself. The do I need a mold inspection triage will tell you which case you are in.
That's the whole price of knowing, published up front, which almost nobody in this market does. Remediation, if the lab says you need it, is a separate cost handled by a removal contractor, and we give you honest ranges for that too so you're never blindsided. See the full cost breakdown.
Four calm steps, under an hour on site.
Call or send the form
Tell us what you're seeing, smelling, or arguing about. Straight price before we book.
The visit
Visual inspection, moisture readings, air or surface samples where the evidence points. Under an hour; you don't leave.
The lab
Samples analyzed at an accredited laboratory with documented chain of custody. The step a kit can't match.
The report
Plain-language results per sample, the likely source, and the honest next step. Yours to take to any contractor.
A report you own, and can hand to anyone.
Every inspection ends in a plain-language report, not a verbal "you've got a problem." It gives you:
- The lab result for each sample, named by what it is rather than by how alarming it looks.
- Whether airborne spore levels are elevated compared with the outdoor baseline taken the same day.
- The most likely moisture source, so any fix addresses the cause and not just the stain.
- The honest next step, including the times the answer is that you do not need remediation at all.
- Dated documentation suitable for a contractor, a landlord, a tenant, or a real-estate file.
Not sure it is worth it yet? Run the two-minute do I need a test triage, or read how a professional test differs from a hardware-store kit.
Straight answers.
How much does a mold inspection cost in London?
Generally $300 to $600 for a residential inspection with lab-analyzed sampling, depending on home size and the number of samples. The exact price is confirmed before we book.
Do you remove mold?
No, and that is deliberate. We test and inspect only, so our report has no sales agenda. You take it to any remediation contractor you choose.
Do I need a test if I can already see the mold?
Often no. If you can see it and you know the source, Health Canada’s advice is to remove it and fix the moisture. A test earns its cost when you need documentation, a species identification, a clearance after removal, or a third-party answer in a dispute or a sale.
Is black mold dangerous?
Some molds produce compounds that affect some people, but "black mold" is a look, not a diagnosis, and only lab analysis identifies what is actually present. Health symptoms are a question for your doctor; what the material is, is a question for the lab.
Can I just use a hardware-store test kit?
A kit can sometimes tell you mold is present, which you often already know. It cannot reliably identify the species, measure the airborne concentration, or serve as independent documentation.
Can you test a house before I buy it?
Yes. A pre-purchase test tells you what a visible spot on the inspection report actually is, and whether the air is affected, before you waive your conditions.
How long does it take to get results?
The visit is under an hour; lab analysis is typically a few business days, with rush options when a closing date or a stalled dispute cannot wait.
What does house mould testing involve?
A walk-through of the areas of concern, moisture readings to find where the water is, and samples where they help: a surface sample to identify a visible patch and an air sample compared with an outdoor sample taken the same day. An accredited lab analyzes them and you get a written report in two to three business days.
How do I do a mold check on my house myself?
Use your nose and a flashlight first. Check the basement walls and floor edges, under sinks, around windows, bathroom ceilings, the attic sheathing near the bathroom fan, and anywhere that has leaked before. A musty smell with nothing visible, or growth that returns after cleaning, is the point where a professional inspection earns its cost.
How soon can you come out?
Usually within a day or two. When a real-estate closing or a stalled landlord-tenant dispute cannot wait, ask about rush scheduling and rush lab turnaround.
Rather just talk?
(548) 290-9788Tell us what you are seeing or smelling and we will tell you whether a test makes sense.
- Testing and inspection only, never removal
- Accredited-lab analysis, outdoor baseline
- Results in a few business days
Get a straight answer
No hard sell. Tell us the situation and we will tell you whether you need a test, and what it would cost.