Mold or indoor environmental tests & inspections: advice for home buyers, renters, occupants.

This article gives advice to home buyers and other people concerned about inspecting and testing for mold in a building where they live or work or a building to be purchased but where there is not already a known mold problem.

This website describes when and how to find mold and test for mold in buildings and how to correct mold problems.

Allergen, Contaminant, IAQ, Mold Inspection and Testing Advice for Home Buyers, Owners, Occupants, Renters

Question: shotgun problem: can I screen my home for all possible indoor air quality problems, contaminants, mold, allergens, etc.?

We have been sneezing and dripping lately when we walk into our house. We think there might be a mold problem, or a mouse problem, or maybe gases from our heating system.

My mother, who lives with us, has a whole series of health complaints, breathing trouble, asthma, hives, and a heart condition. She always seems sicker when she has spent time in our home.

We're also worried that our new carpet off-gassing might be making us sick.

I’ve made some calls to companies about an inspection and they’re all over the place in terms of work done and costs.

Might you know of a licensed environmental inspector in our immediate area?

Or should we just buy some test kits and do it ourselves?

Thanks in advance for your assistance.

Reply: the environmental complaint shotgun problem

You have my sympathy.

You describe what I call a shotgun problem: a blast of serious health worries and a list of suspected environmental worries that contains a cloud of many pellets, each of which could be a concern.

Most often just a few of the pellets in the shotgun complaint blast are the most serious ones; the difficulty is found in sorting out the cloud.

The list of concerns and complaints you cite makes clear that both your personal health and questions about the safety of the environment in your home cannot properly be addressed by email or e-text. You need both

Advice from your doctor: what things in my environment should I look for and remove or reduce: things that would be likely to cause or aggravate my medical complaints

and

Advice from an onsite environmental and building expert: what evidence is there of an indoor environmental problem from mold (water leaks, stains, visible mold), or other common hazards such as mice, insects, use of chemicals, allergens, dust mites, etc.

It can be diagnostic, though very incomplete, to notice where you feel better or worse. In a home where there is an indoor environmental irritant sometimes people feel better when outside or when in another building.

However keep in mind that even this observation alone is not completely reliable, since complaint symptoms can be slow to diminish, or because other environments can contain their own irritants.

The object of these inquiries is the creation of a "to do" list: medical treatments, indoor environmental cleanup or repairs, etc. recommended by experts, in a priority order.

Finally, beware of wasting time and money hiring pseudo-experts who stop by to perform some test or other, like an "air test for mold".

Such testing, as a building screen for environmental hazards is incomplete, very unreliable, expensive, and worse: even if such tests indicate "a problem" they are not prescriptive: the "test" doesn't tell you where the problem is nor what to do about it.

As a result you end up having to pay expensive fees twice, hiring someone more-competent a second time to review the building and come up with an action plan for cleaning or modifications.

So what's needed on-site is a combination of interview, history-taking of both complaints and history of the building, and visual inspection. Tests are secondary in importance.

A useful expert understands building materials, construction, air movement, and common indoor environmental hazards. She makes a thorough visual inspection of the property to look for likely trouble signs, for example: a history of leaks, visible mold, general cleanliness, history of infestations, chemical uses or pesticides, as well as immediate life safety hazards (loose railings, missing smoke detectors).

Specific referrals to home test consultants?

I have no perfect consultant recommendation, and in general, I consider typical "environmental test consultant certifications" for of environmental inspectors to be of but modest use and more often primarily a marketing tool.

Years ago my dog Katie became a Certified Environmental Inspector. I had to help her fill out the paperwork and I confess that I mailed in a check for her for the requisite amount. Shortly thereafter her official diploma and badge came in the mail. She did like sniffing around buildings and was very proud to wear her "expert" badge hanging from her collar.

"Test kits" for indoor mold contamination are in my OPINION not the best use of your money.

If you're looking for mold using a culture plate type kit (very popular and widely sold) you need to know that roughly 90% of molds will not grow in ANY culture whatsoever, and even what does grow may be what likes the media and was just a spore coming in a window - and not the mold problem in the building.

Really? Well not exactly. There are about 200 molds that are commonly found growing in or on buildings and on materials in buildings. Many of those will grow in culture, though of course a mold that likes the culture media will overgrow and may hide what actually may be a more-important contamanint mold that doesn't like the nutrients it's given.

Worse, even if you think that your "air test" (those have 4 + orders of magnitude variation in result from actual so you could be off by a factor of thousan ds), or "mold test kit" or a "test" conducted by your environmental "investigator" suggests that there is indeed an indoor mold (or allergen or some other particulate) problem, you are probably going to have to hire someone all over again to do what was needed in the first place:

A Useful Inspection for Indoor Mold, Allergens, or Other Contaminants

• Interview the occupants, understand the complaint, understand any special vulnerabilities (old, asthmatic, infant, immune-impaired, etc), history of use of chemicals or pesticides etc. at the property, history of building modifications or renovations that may have hidden (or caused) a problem
• Inspect the entire building inside and out to identify likely sources of trouble: leaks or moisture traps (that invite mold contamination), animal entry, pet history, other allergen sources (mice, dust mites, high dust levels in general, poor IAQ, lack of fresh air ventilation, heating system malfunction, etc)
• Inspect or test further the most-suspect areas, using invasive means (test cuts into a wall or ceiling) if appropriate
• Report orally and in writing on what problems were found, where they are, their extent, their cause, and the extent of cleaning and repair work needed.
• Follow-up by responding to questions that arise as work on the building progresses or if anything in the report was not clear

That work needs to be done by an experienced inspector who has absolutely no business or financial relationship with anyone who's going to do the actual cleanup work.

Because doing it right is expensive (more than $1000.) we don't want to start hiring people willy nilly, any more than we want to rely on a completely inadequate or misleading do-it-yourself "mold test" kit (not to mention the problem could be something other than mold and might not even be building-related).

For that reason, you will at the very least want to read

MOLD / ENVIRONMENTAL EXPERT, HIRE ? helps decide if it’s appropriate to bring in an pro.

CONSULTANTS & EXPERTS DIRECTORIES gives directories and contact information for various types of experts who may be helpful

HOW MUCH SHOULD YOU PAY discusses how to figure out if you are paying too much or too little for an environmental inspection and testing

Mold Testing Advice for Home Buyers

Because it is perfectly normal to find some mold spores in air everywhere and because mold is ubiquitous in the environment, it makes no sense to attempt to buy a "mold free" home, nor should your objective be to test a prospective new home to be sure that there is no mold therein.

You can't eliminate mold in the environment indoors nor outside. If you could we'd all be in trouble as nothing would ever decay and we'd all be so buried in junk and debris that nothing could grow on the earth.

But we don't much like to see growing mold contamination on surfaces or materials indoors and certainly not on our walls, ceilings, or furniture.

There we remove it or clean it off. Because there are potential health risks involved, especially for some people, and because there are significant costs involved in large mold remediation projects, home buyers often contact us to ask about testing a home for mold during the home buying process.

A thorough building investigation for problematic mold needs to address hidden mold reservoirs, for which our approach is to complete a detailed inspection and building (leak) history as well as to record occupant observations and complaints.

A low-cost superficial test or superficial "quick look" for problem mold (such as an "air test for mold", a "home test kit for mold" or a "mold culture test") is likely be a waste of money since those approaches to screening a building for mold contamination are unreliable.

Certainly if problem mold is visible that's unambiguous.

But superficial visual inspections and grab-tests for mold in air or on surfaces, performed without being accompanied by a very thorough building inspection, history taking, and occupant interview, have a high risk of missing important reservoirs of problem mold in a building.

Some "mold inspectors" may charge as much as a true expert to examine your building ($750 to $2000) but in fact may be doing little more than a quick inspection for visible mold and a few superficial tests. This is also an unreliable approach.

Since water and moisture are gating factors for indoor mold contamination I recommend that you start with a thorough inspection of the building for conditions likely to produce a mold problem - leaks, moisture traps, bad ventilation, history of flooding, etc.

Details are at MOLD CULTURE TEST KIT VALIDITY

and at MOLD LEVEL IN AIR, VALIDITY

Why Can't I Just Collect a Mold Sample and Based on That, Decide if the House We're Buying Has a Mold Problem or Not?

Reader Question: Quick Lab Turnaround on Mold Tests

Dear Lab Director:

We desperately need the results of the mold sample we collected yesterday ASAP. We cannot proceed with the closing process until we have these results, and our house purchase closing is scheduled for Friday. - Worried in Po-Town.

Reply: Don't Decide to Buy or Not Buy a Home Based on a "Mold Test"

Dear Worried:

While most mold test labs and forensic laboratories can provide very fast mold sample analysis - 24-hours or less after a sample is received, a home buyer who is worried about a possible costly mold contamination problem in a building should certainly not be deciding to go ahead with the sale or not simply based on a "mold test".

This is even more true if the mold test or mold sample was collected by someone who is not an expert.

If there is a reason to be worried that there is a significant mold problem in a building, and if you have not had an expert perform a very thorough, visual inspection, even the most technically proficient "test", alone, is unreliable.

A mold test, even a good one, is a screen that might detect evidence of an indoor mold problem.

But absence of evidence of mold in a building is not, unless accompanied by an appropriate, expert, onsite investigation, never evidence of absence of a mold problem.

If you have a particular concern about the building, and regardless of the outcome of the lab work, we recommend that you discuss this with your attorney, your realtor, and your home inspector. Your attorney may recommend that you either delay the closing, or if agreeable to the seller, obtain some estimates to establish a "worst case" guess of possible mold remediation cost and escrow that amount long enough to give yourselves time for an expert assessment.

Does this mean every home should be inspected and tested by an expert to look for mold?

Of course not. 

At MOLD / ENVIRONMENTAL EXPERT, HIRE ?

we discuss some criteria that help decide if it is appropriate to bring in a mold expert, such as pre-existing evidence of a problem: large areas of visible mold, evidence of or an historical report of building flooding, significant plumbing leaks, or other leaks, etc.

Reader Question: How do I make sure a previously-contaminated home I'm buying is not contaminated with black mold

Illustration:

Shown here is a bar chart giving mold test results in counts of spores per cubic meter of air in a building - provided by an InspectApedia.com reader 2018/04/24 and further discussed in FAQs at the end of this article.

[Click to enlarge any image]

Editors:

I am looking into purchasing a home and found some histroy on the home that led me to do a mold testing.

The house used ot have black mold in the basement and in the second floor bedrooms (rooms D/T windows being knocked out when abandoned).

The house has been "gutted" and remodeled, however, having a 2 year old son- I want to make sure I understand things okay. - CB April 18 2015

My husband and I are looking at purchasing a house that we have an accepted offer on.

We came about some pictures that showed the hosue before it was "gutted" and came to realize there was extensive amounts of black mold in the basement (then unfinished) and second bedroom floors (windows were knocked out when abandoned).

The house has been completely remodeled. We did a mold analysis which I have the results of. On the second floor, tehre was 1 raw count or 40 spores per cubic meter of Chaetomium- what is this and is this of concern?

Also in the basement, there was 1 raw count or 40 spores per cubic meter of stachybotrys. Is this of concern as well or with the histroy is this okay and small/safe?

Thank you for any guidance you can give me! We are going at this blindly! - CB April 18 2015

Reply:

I'm sorry to give bad news, but "spore counts" as a building screen for mold are very unreliable, and looking for "black mold" is also dangerous since of the 200+ common mold genera/species that can grow indoors in buildings or on building contents, many of which are harmful, the "black" group is but a small subset.

Worse, if you used a culture test, since 90% of molds don't grow on culture, your test was basically 90% wrong when you opened the box.

If you're worried about mold start with a thorough building inspection to understand its leak history: what got wet, where did water go, what cleanup was done, vs. what was "covered over".

If there are reports or photographs of the prior mold contamination those will be a helpful source of information on what work was done.

If the mold contamination was serious - more than 30 square feet of contiguous and non-cosmetic mold - then a professional should have been used to perform the cleanup.

In that case there should have been independent mold inspection reports from before and after the cleanup job both indicating what cleanup was needed and indicating that the cleanup was properly conducted.

At MOLD CLEARANCE INSPECTIONS we describe how that final inspection should be performed.

A competent onsite inspection by an expert usually finds additional clues that would permit a more accurate, complete, and authoritative answer than we can give by email alone. You will find additional depth and detail in articles at our website.

If you have reason to think that the cleanup was inept, or that contaminated drywall, insulation, or other materials were not removed, then select the highest-risk points and if necessary make a small test opening to inspect cavities such as a ceiling or wall.

Reader Question: mold under my house came in as 120 and upstairs at 1200 - is that bad?

Hi I recently had a mold inspection " the number for under the house cane as 120" but in our room it came back as 1200 an thats from air samples " is this bad ?

What should we do ?an its a single family home an we do not have ceiling fans " please help me understand. - S.L. 14 April 2015

Reply:

I'm sorry but no one can make much sense out of arbitrary mold count numbers: we have no idea what they represent.

1200 what? Oranges? How was the test conducted, what mold was found, what's the reliability of the test? An arbitray number of "mold" alone is little more than confusing.

Since you had a mold inspection, surely the inspector actually inspected the home. What did he or she say about the mold report when you asked?

Reader follow-up: consultant says "mold is bad, see a doctor, hire a lawyer"

He said that it was very bad in the home .. and i should seek medical advise an contact an attorney

Reply: time for a mold test consultant to refund the fee?

If that is all you were told in my OPINION I'd start by asking for a full refund of what you paid.

Send me all information you have and I will perhaps be able to say something useful.

But just the data you've given me is not enough to make sense of the advice you report having been given.

Why to Hire a Good Home Inspector for a Preliminary Check for Mold-Producing Conditions in a Building

If your "mold inspector" is simply going to enter the building, collect a few air, surface, or culture samples, and perhaps report on obvious visible mold in the living space, you're not receiving a very professional nor very reliable service.

An experienced, thorough, detailed, qualified home inspector will be much better at recognizing those (mold-conducive) conditions than a typical "mold inspector" or a typical industrial hygienist who does not know building science and who lacks experience in identifying where and why mold problems occur in buildings.

Home inspection standards, training, and experience teach inspectors where water, leaks, and moisture problems occur in buildings. Here are some examples of water or leak history problems that can create a hidden mold problem in a building:

• A one-time basement flood due to a burst pipe, sewer backup, or area flooding - the basement may now look clean and dry but significant mold contamination may be present in basement walls, under carpeted floors, or in building insulation
• An older home with poor under-roof ventilation may have experienced condensation and moisture-related mold contamination of the attic insulation, roof sheathing, or hidden side of ceiling drywall; in northern climates such a home may have had ice dam leaks into wall cavities, producing hidden mold in building walls.
• A home where plumbing leaks from an overflowing bath tub, leaky fixture traps, or supply piping leaks may have had leaks into wall and ceiling or floor cavities, leading to hidden mold contamination
• A home with a history of recurrent a damp or wet crawl space is at extra risk of moldy crawl space insulation, producing mold species whose spores move upwards into the occupied space by riding normal air leaks and air convection currents.

A home inspector is expected to recognize these leak and moisture problems even though s/he is not performing an environmental inspection.

Also see MOLD TESTING by HOME INSPECTORS? for an opinion-text on the marketing of mold tests as a revenue source for home inspectors.

A Home Inspection is not an Environmental Survey of a Building

Unless the inspector happens also to be trained in mycology, forensic microscopy, and aerobiology, s/he will be focused on the condition of the building, not just on the presence of mold, but such a person is the best expert to identify leaks and moisture problems among other building risks.

Don't try to force the inspector to give an environmental report - it's outside the scope of a home inspection.

But do ask the inspector to be extra thorough and detailed about leaks, moisture, ventilation defects. And of course any conscientious and respectable inspector will also tell you if s/he happens to also actually see mold (or other out-of-scope hazards) during the inspection.

Educate Yourself About Building IAQ & Indoor Environmental Issues, Inspection, Tests

The more you can bear reading up on IAQ issues and investigations, the better you can sort out the baloney-sellers from the more dedicated, serious environmental professionals.

Here are some more information sources:

To Look more carefully at the building yourself - this website has articles on how to look for problem mold or other indoor air quality issues, see these online guides:

ENVIRONMENTAL HAZARDS - INSPECT, TEST, REMEDY - home

ASBESTOS IDENTIFICATION IN BUILDINGS - home

BACTERIA, Mold, & Pollen

BIOLOGICAL POLLUTANTS

CARPETING & INDOOR AIR QUALITY

COMBUSTION GASES & PARTICLE HAZARDS

DUST SAMPLING PROCEDURE

EMERGENCY RESPONSE, IAQ, GAS, MOLD

FIBERGLASS HAZARDS

FLOOD DAMAGE ASSESSMENT, SAFETY & CLEANUP

Formaldehyde testing - FORMALDEHYDE GAS TEST KITS, METERS

and also see WHEN SHOULD YOU TEST for FORMALDEHYDE

HUMIDITY CONTROL & TARGETS INDOORS

LEAD POISONING HAZARDS GUIDE - home

How to look for mold - MOLD DETECTION & INSPECTION GUIDE

Appearance of mold - MOLD APPEARANCE - WHAT MOLD LOOKS LIKE

Stuff that is not mold - MOLD APPEARANCE - STUFF THAT IS NOT MOLD

How to use your flashlight - USING LIGHT TO FIND MOLD

How to inspect and test for mold in a home you are buying - BUYERS GUIDE - home inspections for mold

ODORS GASES SMELLS, DIAGNOSIS & CURE - home

OIL TANK LEAKS & SMELLS

RADON HAZARD TESTS & MITIGATION - home

WATER ODORS, CAUSE CURE

To Evaluate the leak and moisture history of your building see these instructions:

Overall building risk for mold - MOLD EXPOSURE RISK LEVELS, and if there seem to be particularly high risks (building history, what you see, complaints or health risks of occupants) it might be appropriate to hire an expert

When to Hire a Professional - MOLD / ENVIRONMENTAL EXPERT, HIRE ? helps decide if it’s appropriate to bring in an pro.

...

---

---

ADVERTISEMENT

---

---

Reader Q&A - also see RECOMMENDED ARTICLES & FAQs

On 2021-09-07 by inspectapedia.com.moderator (mod) - buying a mold-contaminated house

@Lettie,

With all due respect, I can't comment on the number in your mold test because it is absolutely meaningless. Please use the on Page search box to find our article that explains the point under the topic

MOLD TEST ACCURACY

On 2021-09-06 by Lettie

I am in the process of buying a house which was disclosed as a cannabis grow op house. The city signed off on the report stating everything was cleared. I ordered an independent mold inspection and the overall Detection Limit (spore/m3) number came back for the inside and outside of the house at 13.3. Should I have any more independent tests done since it was a grow op house?

This Q&A were posted originally at InspectApedia.com HOME

Question: black mold in our bedrooms, where do I find financial assistance to have it tested

(Aug 12, 2011) Dawn Entsminger said:

My boyfriend, my 15 yr old daughter and I are living together. My boyfriend is a disabled veteran and I am a single mother who is unable 2 work due to herniated discs and waiting for preapproval from title 19 for surgery. We have a very limited income right now.

We have black mold in both bedrooms and bathroom. I have asthma and allergies and my boyfriend has allergies also. we are buying our home. Where would i find financial assistance to have it tested and removed

Reply: don't buy a home if you can't afford to find out what it will actually cost

Dawn:

First, if there is more than 30sqft of mold in the home, unless it is a cosmetic mold described in this article:

MOLD APPEARANCE - WHAT MOLD LOOKS LIKE

(which it probably is not), then you don't need a test to decide that action is needed.

You need legal advice from an attorney who is actually working for your interest (not someone recommended by the seller or realtor). You should not buy the home without having an expert inspection of the building for overall condition, including the probable need for a mold cleanup.

Otherwise you may get in well over your heads - able to "buy" the home but not able to keep it and repair it and make it safe and functional. Your attorney may advise about escrow funds or paying for necessary inspection, testing, and repairs as an adjustment of the price of the home.

Of the possible costs involved, the cost of a home inspection and first pass mold inspection are trivial in comparison. If you cannot afford those, you cannot afford to buy the home.

In my experience if a home being bought is discovered to have substantial defects that affect its usability and habitabiity, it is customary for the buyer and seller to negotiate over the cost to cure those conditions. You should ask your attorney for advice and help before proceeding.

In your case this is especially important as people with disabilities or undergoing surgery could be at serious extra health risk in a building with high levels of allergenic, pathogenic, or toxic mold.

Finally, if you are having to seek financial assistance for a "mold test" or "mold inspection" I cannot imagine how you could or should be considering buying a home.

The costs of buying a home, including both the price itself plus fees and services and interest on loans will be enormously greater than the cost of a building inspection. In my opinion if you cannot afford to inspect a building you're buying to find out its condition (and thus to learn what other significant expenses are in your future), you can't afford to buy it.

Keep us posted. Send along photos if you like (see CONTACT links on our pages) and I'll see what further comments I can offer.

...

Continue reading at WHAT DOES INDOOR MOLD LOOK LIKE, or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see these

Recommended Articles

• ACTION GUIDE - WHAT TO DO ABOUT INDOOR MOLD describes what to do if problem mold is found in a building
• HIDDEN MOLD describes methods used to find hidden mold in buildings
• MOLD DETECTION & INSPECTION GUIDE describes how to look for mold in buildings
• MOLD / ENVIRONMENTAL EXPERT, HIRE ? contains advice on when to hire a mold consultant to inspect and test a building. We identify factors such as the presence of people at extra medical risk (asthmatics, immune-impaired, infants) and leak history that increase the risk of a significant mold problem or that otherwise justify the expense of a thorough building survey for mold contamination.
• MOLD CLEARANCE INSPECTIONS describes post remediation mold clearance inspection and test procedures, which could form a reasonable mold-screening inspection and test for a building
• MOLD LEVEL REPORTING - what levels of mold should be reported and how: do very precise numbers mean that the mold test was at all accurate? (No.)
• MOLD TEST KITS describes simple low-cost methods to screen building surfaces or building dust samples for problem mold
• MOLD TESTING by HOME INSPECTORS? opinion on the marketing of mold tests as a revenue source for home inspectors.
• MOLD REPORTS describe what should be found in a usable and competent mold test and inspection report
• WHAT MOLD LOOKS LIKE provides a photo library that helps anyone recognize mold on building surfaces and includes links to articles describing materials that are not mold but may indicate moisture problems that increase mold risk, as well as links to articles describing other non-moldy stuff often mistaken for mold

Suggested citation for this web page

HOME BUYERS or OCCUPANTS GUIDE to EVIRONMENTAL or MOLD TESTS at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

Or see this

INDEX to RELATED ARTICLES: ARTICLE INDEX to MOLD CONTAMINATION & REMEDIATION

Or use the SEARCH BOX found below to Ask a Question or Search InspectApedia

Ask a Question or Search InspectApedia

Try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.

Note: appearance of your Comment below may be delayed: if your comment contains an image, photograph, web link, or text that looks to the software as if it might be a web link, your posting will appear after it has been approved by a moderator. Apologies for the delay.

Only one image can be added per comment but you can post as many comments, and therefore images, as you like.
You will not receive a notification when a response to your question has been posted.
Please bookmark this page to make it easy for you to check back for our response.
Our Comment Box is provided by Countable Web Productions countable.ca

Citations & References

In addition to any citations in the article above, a full list is available on request.

---

ADVERTISEMENT

---