When to hire an expert to inspect & test a building for environmental, health, safety, mold, IAQ hazards:
When to Hire a Professional to Inspect or Test for Mold or other Contaminants. This article describes how to determine that you should hire an expert for on-site mold or other indoor contamination inspection and testing.
Not every environmental, safety, or mold contamination worry merits a costly onsite investigation - hiring an onsite expert or even performing mold testing for trivial mold cleanup jobs is expensive and usually unnecessary.
But failing to hire an expert when one is needed can itself be a costly mistake of a different kind.
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The purpose of the advice below is to help readers decide when it is appropriate to perform mold inspection and testing on a building.
We want to know how and when mold testing is appropriate, and we want to avoid spending money on mold testing when it is not necessary. Also we want to avoid spending money on unreliable mold "tests" and inspections that do not validly support any conclusion about the building.
Our moldy home photograph (left) shows a cup fungus growing along the wall/floor baseboard trim in a home that had suffered a prolonged plumbing leak.
The visible fungal growth is quite obvious. What is less obvious, and what will require an expert inspection, is the extent of mold cleanup needed in the building, possibly including hidden mold in wall and ceiling cavities.
The answer to the "when to hire an expert" question hinges on the answers to the questions given in the table below. Or if you don't like decision tables try our "expert hiring RULES of THUMB" that follow the table.
When to Hire a Mold or Environmental Inspector: Decision Table
|Is there an indoor air quality emergency?||Yes: immeditaly get outside into fresh air, notify building occupants, seek help;|
|No: whether or not you need an expert depends on the questions & answers below. If you are not sure if an emergency exists check out the articles listed at right.|
|Large visible mold area: Is there a large area of visible, non-cosmetic mold in the building - more than 30 sq.ft. of contiguous mold of any color or texture?||Yes: you need a professional to define the scope of cleanup needed and to explain how to correct the cause of indoor mold contamination.|
|No: whether or not you need an expert depends on the questions & answers below.|
|Mold "Test" Results: do results of a mold screening test, air test, surface test, or culture test suggest that indoor mold contamination is present?||
Yes: provided that the mold screening test was properly conducted and has reasonable validity, you need a professional to define the scope of cleanup needed and to explain how to correct the cause of indoor mold contamination.
Watch out: because it is possible to find some mold growth in just about any building, collecting a sample of such mold from what is actually a trivial or small area of indoor mold contamination would not, of itself, justify a costly and extensive building mold investigation.
U. MINNESOTA RULES discuss levels of mold contamination & other factors.
No: Watch out: while a "positive" mold test result can indeed suggest that a hidden mold problem is present in a building, negative results on just about any mold test cannot assure that no problematic mold reservoir is present.
Whether or not you need an expert depends on the questions & answers below.
|Other evidence of an IAQ problem: is there other evidence of an indoor air quality problem such as building-related occupant complaints||
Yes: hire a professional to identify & investigate building areas of highest risk of a hidden or non-visible problem or hazard
|No: whether or not you need an expert depends on the questions & answers below.|
|Other high risk factors: are there other high risk factors such as vulnerable building occupants, non-specific building-related health complaints, or a history of building leaks or floods||Yes: hire a professional to identify & investigate building areas of highest risk of a hidden or non-visible problem or hazard||
FIVE RULES of THUMB help decide if a building investigation is warranted
|No: most likely a building investigation and further testing for mold contamination are not justified.|
|This table is part of a series of advisory steps about mold contamination investigation found at MOLD / ENVIRONMENTAL EXPERT, HIRE ?.|
IF these conditions are present in a building being evaluated for mold contamination risk
THEN mold may be a problem in the building. -- N. Carlson, U. Minnesota [Comments added by DF]
Continue reading at DEFINITION of MOLD EMERGENCYor select a topic from the More Reading links shown below.
Or see MOLD TEST vs MOLD INSPECT
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My husband, 5-month old son, and I recently moved into a water-front basement apartment (about two weeks ago) and immediately noticed our allergies flair up. My husband and I are both allergic to mold, but we can't find more than small amounts on the floor boards. In the closet of our bedroom, there is a boarded up septic pump that smells terrible and might be contributing to our problem. Our landlord is not terribly concerned at the moment. What can we do to test the area? We have all developed colds and wake up each morning with terrible congestion, drainage, and headaches. - Rosi B.
There are a few things an experienced investigator hears that trigger a sort of "red flag" or prejudiced expectation of trouble, including basement+apartment+waterfront. The worry-o-meter points up a bit more for "mold allergies"
and more for "septic odors".
You are describing at least two possible problem areas: mold and sewage pathogens/sewer gas. And there could be serious health risks. Notify the landlord in writing of your concerns immediately. You can hire an experienced environmental investigator (search our website for "Mold and Allergen Inspectors & Testing Consultants" for a directory that might be helpful. Discuss the inspector's experience, and the extent of actual inspection, not just "testing" before hiring someone. Tests performed without an expert inspection are not worth much.
I had energy efficient windows installed in my townhouse over a year ago. This past spring one of the master bedroom windows leaked after a rain storm because the caulking failed. The company immediately came out and re caulked the window and it hasn't leaked since. My concern is that I now have a water stain under the window on the drywall, and since I have a mold allergy, I'm wondering if there might be mold on the inside of the drywall.
I read your article on testing the dry wall but as mentioned in the article would rather not cut into it unless it's necessary. I looked at other articles but didn't see one with a picture resembling the water stain I'm concerned about. What would you recommend? By the way, this is a very helpful website. I was considering using ozone for any possible mold in my place but see from your article that's not a good idea. Thank you. - G.N.
A competent onsite inspection by an expert usually finds additional clues that help accurately diagnose a problem with mold, hidden mold, and with tracking down just how much water leaked into the building and where it went. Indeed a basic axiom in deciding the level of risk of an actionable hidden mold reservoir is to identify places where water has leaked into the building, asking how much water leaked where for how long and just where did it go in the building? Follow the water.
That said, here are some things to consider:
First, how disappointing that your new windows leaked - certainly a wet wall below a leaky window is not particularly energy efficient, and indeed it could become a mold reservoir.
Second, the risk of a mold problem that you can't see but that is significant enough to merit removal is not something I nor anyone should guess at by email with so little information. In the article above at MOLD / ENVIRONMENTAL EXPERT, HIRE ? we give some suggestions on how to decide if it's justified and appropriate to hire someone to perform a more competent mold inspection at your building. Testing alone is not reliable.
Third, I would not rely on "mold tests" alone to decide if further investigation is needed. A "mold test", especially an air test for airborne mold, performed without an expert diagnostic inspection of the building is just not reliable in cases where the result is "negative".
We moved into a basement apt last nov and both scott and myself have been on and off sick ever since we moved in, we had management come to investigate the problem and so now they are going to replace the windows, my question is this, by replacing the windows, which were the main causes of mold in our apt, i know its in the carpet and in the walls, we both suffer from hiv and we want to move out of this place, how do we go about getting out of our lease without getting taken advantage of?
our lease is up oct 31 and we cant stay that long, we have already applied for a new apt in a different area and got accepted and plan to move out on sept 10th,our lease agreement states that if we break our lease we will have to pay 1 and a half times our rent which is about $1500 and we just cant do that, what advise can you give us before we go and give our notice? please advise, thank you
clay and scott
I would NOT assume that your windows were the main cause of a mold problem, though certainly leaky windows or lots of condensate running into walls could be significant. Often a basement apartment has a history of leaks into walls, sometimes prior floods or water entry, and thus there is a risk of larger hidden problem mold reservoirs that can be found by an expert who combines visual inspection, history taking, and strategic testing, perhaps even some careful looks into wall or ceiling cavities in highly suspect areas.
As tenants you may have trouble with the cost of a competent inspection (about as much as your rent) and with the need for invasive measures. If you've notified the landlord in writing and no one will act, and you want to move, you need to consult a real estate attorney. Typically the combination of actual credible evidence of a habitability issue that the landlord won't or can't address is enough to justify breaking a lease.
Beware: if your apt is really moldy your possessions may need to be cleaned before importing them to a new home.
Thank you for your excellent site! I am in a quandry about mold testing & remediation. We live in a relatively new home (about 10 years). Because I suffer from allergies & sensitivities, we had this house thoroughly inspected when we purchased it 7 1/2 years ago, by both structural inspectors & an environmental inspector (for mold & radon); both inspections were passed easily, and the environmental inspector's report called our home "one of the cleanest" he had ever tested. But I am now (and for some time) smelling mold. Nobody else does, but everyone knows that my nose knows. We have had several inspections done by various professionals, and so far we have found and corrected 2 small leaks and small mold problems ... but I still smell mold.
The only possible source I can imagine is the cathedral ceiling, which we cannot inspect properly because there is no attic there. The attics on the sides of the houses have been inspected & seem clean, and the roof has been inspected and declared good, no leaks.
One friend has suggested that perhaps there is simply inadequate air circulation in the cathedral ceiling which allows some mold growth in the insulation. We have had an infrared camera inspection, and no obvious leaks/cold spots were found (but some vaguely cloudy areas that the operator could not interpret). I have called more mold inspectors, who want to do very costly sample testing. I don't see the point: I smell the mold, I want to know WHERE it is and get rid of it; I don't really care what kind it is.
So, my question: Can we simply seal the attic/ceiling to prevent air infiltration and avoid ripping out the entire ceiling of our home? If not, what can we do to reliably verify if this is the source of the smell, or where else there could possibly be mold, other that ripping out our ceiling? Thank you! (And apologies for the long & disjointed letter)
Lisa, if you smell mold, there is probably a mold contamination source to be found and remedied. It may be possible to home in on the problem if your "expert" really is one - someone with both training and experience in finding building mold. We use a combination of case history, occupant complaints, and a thorough visual inspection of the building for history of leaks, likely moisture problems, and similar clues to identify the "most likely" areas of hidden problems that justify further investigation - often by a small test cut into a cathedral ceiling to use your example.
Your description of your "experts" makes me wonder about the services you received: I wouldn't expect an experienced professional to "pass" or "fail" a building. Those terms are simply too much of an over simplification; most experienced inspectors speak with more caution, and will tell you whether or not they were able to find evidence of a problem that merits further investigation or not.
I would not just "seal" the ceiling as a mold "cure" without first finding out where the problem mold is, how large the mold reservoir is, and what caused it. Why?
So first let's find out if there is a mold problem that needs removal and find out if there is a roof leak that needs repair.
I have a mold kit that someone gave me but it does not have an address where to send it for results. I work in a school that I understand is infested with mold but they have yet to do anything about it. I have been in & out of doctors offices & the hospital with symptoms that are believed to be from the mold, & the only mold I am exposed to is here at my school. I have always been extremely healthy, but now suffer with asthma & allergies due to mold. In fact, I have to go to an ENT for weekly injections for mold. I don't mind paying for the test, even though my school should be ultimately responsible. Can you help me? Please!!! - Anon., Tulsa
A competent onsite inspection by an expert usually finds additional clues that help accurately diagnose a problem with building indoor air, with visible or hidden mold or other contaminants, and with the cause and remedy that should be understood and acted upon - not things you can decide from a mold test kit. That said, here are some things to consider:
You can send your mold test kit to any mold test lab - most of them anyway - will accept it and charge you an analysis fee. But you should realize, especially as you express health concerns, that "test kits" for mold are basically unreliable when used in the absence of an expert onsite inspection, occupant interview, case history. Only about 10% of molds will grow on any culture whatsoever, so you're about 90% wrong when you open the box. Details are at Mold Culture Plate Test Errors.
Therefore if you or others have reason for serious concern about mold and indoor air quality in your workplace, it seems to me smarter to be sure that a competent expert is engaged to help assess the situation. To avoid any appearance of conflict of interest, having given the advice in this note, that is not a service that we would provide.
Above beginning at MOLD / ENVIRONMENTAL EXPERT, HIRE ? we provide advice that can help you decide if hiring a mold expert to inspect, interview, and perhaps conduct some testing is appropriate.
I recently had a air quality sample done of our house. Asp/Pen outside was 920, on the first floor it was 644 and in the basement it was 2850. There are no visible signs of mold. Should I be concerned and do I need a mold remediation specialist? It's a finished basement.
thanks! - John G. 10/7/2011
John, my best advice on deciding if you need to hire a mold investigator or mold specialist is summarized in the article above. There you'll see that we list a variety of factors one would consider in making a decision to go further or not. Depending on various factors such as occupant health risks, building complaints, visual observation of water or leak history, etc., even a small visible mold colony could prompt further investigation.
Your high indoor Pen/Asp count is roughly 3x the outdoor count (and of course the outdoor count might not even be the same mold spores as found indoors) and your basement count is highest, suggesting that if there is a substantial problem mold reservoir that's where to start looking. That alone might be enough to prompt further inquiry.
Did you ask the expert you paid to perform mold tests for an interpretation of the rest results? If not, you're not getting what you paid for.
I was wondering I could email you a few photos of my basement rafters (I can not figure out how to attach the photos to this comment). The area is below my living room (no overhead water source) and this mold-like staining is on several rafters intermittently, as there are rafters between the stained ones that have no visible mold. There has been no water intrusion and the rafters have been dry. In the room is our HVAC and other mechanicals. I have reviewed your articles and it seems like it may be the cosmetic variety that is harmless. However I do notice a moldy odor in the basement during the rainy/humid seasons. I am getting conflicting ideas based on your articles about mold odor meaning there is definitely mold that should be dealt with and cosmetic mold. - Anon 12/26/11
Mold on basement rafters?
We would be glad to take a look at photographs that help explain a question you pose to InspectAPedia experts. Use the CONTACT links found at the top or bottom of our web pages. While examining a photograph is never a substitute for an expert on-site inspection, and while often an expert will find important conditions that a layperson may have not noticed, photographs do provide excellent information that can often allow us to make useful comment.
I and my kids have been sick constantly for the past 4 months with respiratory issues. My husband thinks it's just because my son started preschool but I was concerned so I hired a professional to do a mold inspection and test. The inspector found no visible sources of mold, water damage, etc. He thought our house was pretty clean.
But then the air samples he took came back from the lab with around 300 count of Penicillium/Aspergillus mold spores in the bedrooms where the samples were taken. The final report called for $2000 of professional remediation cleaning of the bedrooms using HEPA vacuuming, etc from their company to solve the problem solely based on the air samples taken because the inspection otherwise found nothing.
At this point, I"m not sure what to do. I'm not sure whether I should move forward with this costly remediation when there isn't a source of mold found. I'm not sure this remediation of cleaning out the rooms with even make a difference overall. And I'm not convinced we have a problem with an Aspergillus/Penicillium spore count of 300 in the air. If I was convinced then I would spend the money but it's a lot of money for us. I'm not sure what to do. - Felicia 5/29/2012
To clarify a bit further. The outdoor asp/pen count was 90. So the inside count was 3x the amount as outside at 300. But I did read in another inspectapedia article that clean building counts ranged from 250-600ish. I read the article above but am still not sure what to do. Thank you for your help. - Felicia
Felicia the report and advice you received sound very questionable to me; if there is a high indoor Pen/Asp count then one needs to look for and find the source of that material. Just surface cleaning of exposed areas is premature and a waste of money - it's treating the symptom without finding and fixing the cause.
An expert inspector examines the entire building, inside and out, and when there is no visible mold of consequence, but testing and case history and other observations suggest a mold problem, then s/he looks for and investigates further into the most likely locations of a hidden problem, often by looking at the building leak history or design that points to most likely locations for hidden leaks or moisture traps.
Watch out: For an article with many examples of how one might interpret various mold inspection or mold test results with different "spore counts" take a look at MOLD STANDARDS. But keep in mind that very trivial changes in how a "test" is conducted can result in several orders of magnitude difference in the "count" number obtained, and worse, some tests that detect mold are detecting the mold that liked a culture not the mold that is a problem in the building.
1. Comparing indoor to outdoor mold spore counts, while a common practice, is highly unreliable as it's often comparing apples and oranges. For example outdoor Pen/Asp could be a completely different genera/species than the indoor mold, thus making their comparison irrelevant;
Also even very low spore counts can indicate an indoor mold reservoir in certain cases, such as finding Pen/Asp spores in connected spore chains.
2. Please take a further look at the article above, including the FAQs section, intended to give you some criteria to help decide when it is justified to dig further into this question for an individual building. Then let me know what questions remain.
Use the "Click to Show or Hide FAQs" link just above to see recently-posted questions, comments, replies, 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.
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