What should mold “treatment” look like?

Several weeks ago I reported a mold like substance on the sheathing in the attic. I suspected and reported that lack of ventilation may have contributed to the condition due to the mold like substance only on the north side of a ranch style house with a hip roof. I recommended corrective action as to cause and treatment and removal of substance.

Yesterday I re-inspected the house and found the mold like substance still present, although it appeared to be much lighter in color. The seller said that he “treated” it. Obviously, without testing, it cannot be determined if the unknown “treatment” was successful.

Assuming that the cause was corrected, is treatment enough? Should it have been treated and removed? Treated, removed and sealed? What is the best method?


To the best of my knowledge there are inhibitors that I’ve seen sprayed in attics and crawspaces, of course the condition of the substraight determines whether or not treatment is a viable option.

Whenever I see an area that has been treated, I report that treatment was observed and on any organic substances, if any, that were still visible and recommend testing by a qualified company.

Personally I would shy away from re-inspecting treatments such as these and tell my clients to get receipts from qualified mitigators and any transferable warranties that may be available.

And of course the root cause should be addressed also, which is usually consists of inadequate or lack of attic venting, bathroom, kitchen, or dryer vents terminated in the attic.


A thermal cam would be in order on initial discovery to check for moisture.
The only matter here is the owner did it. I really don’t care what he did/did not do. I’m not clearing that.
Without a licensed remediator/contractor’s papers, I would say basically the same.

I would want it removed, treated, sealed, BUT we don’t know what the heck it really is.

The north side gets the least amount of sun, heat so most likely poor circulation.


So would I if for nothing other than making sure any corrective action was effective. The seller’s argument was “it’s the attic, who cares if there’s a black stain.” My view is that “if it looks like mold, treat it like mold, until it can be verified that it’s not”. The seller reluctantly agreed to remove the stain and seal it.

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Personally, I would not wade into these waters very far.

I would report what I see. Then state Testing or determining exact type of substance is beyond the standards of practice. Recommend further evaluation by a qualified remediation contractor and perform corrections as needed. Have the seller provide all documentation such as invoices and warranty information.

Is that the solution or just a treatment of the symptom? Run Forrest Run. :slightly_smiling_face:

(Kevin, I replied to you…It was meant for Richard. But your point about the cause is spot on)


Tell your buddy (ha ha) to use this.
Regular household paints adhere very well to Concrobium Mold Control-treated surfaces. If you wish to treat and then repaint a moldy surface, first apply the solution to clean the affected area. Allow to dry and then repaint.

This stuff will physically crush the spores.
Regular bleach may get rid of some if it, but background mold will still be present.

On the other hand if you recommend how to proceed, he’ll blame you if he screws up.


This is a great question - I inspect in two areas (Oregon and Maui) and the routine is different in the two places. All the companies in Oregon that I’ve seen leave no trace after a remediation. They either clean it (or is evaporates with the cleaner?) or they spray a white paint over it. Over here in Maui I’ve only come behind a remediator once so far and it really didn’t look any different after the repair but the company swore they were done and it had been fixed.

As others have said, be very careful about how far you get into it. The old, “write what you see,” is the best way to go. On my Maui one that was still visible I advised the client it will undoubtedly raise questions anytime the house is sold and that he should get lots of documentation guaranteeing a fix. Of course, I also documented with pictures in the re-inspect report.


I agree with Brian Cawhern, “Personally, I would not wade into these waters very far.”
In the mild California climate, doing structural pest inspection, we identified wood-destroying fungus on the underside of a roof deck like this and attempted to also identify and correct the underlying condition. Often, it would be a one-story ranch home with a damp crawlspace below and a very poorly ventilated attic above. Although we did not do mold abatement, we used Borate-based treatment products such as Bora-Care and Timbor from Nisus that were extremely effective at preventing fungal growth. However, after drying, the wood looked the same as before after a Bora-Care treatment, or had only surface remnants of a crystalized salt with Timbor treatments. The bright splinters coming through the roof deck makes me think this was a condition from the previous roof, and that there is no decay. Since the wood looks to be structurally sound, treatment or abatement following by ensuring adequate attic ventilation would make me happy. Matt Fellman’s comment that “they either clean it…or they spray a white paint over it” is important. If that isn’t done, it still looks scary and places the efficacy of any treatment in doubt. With fungus infection, we would scrape the wood surface with a wire brush prior to treatment.


Stay Away, I do Environmental Also. Why do they have you do the re inspect when you did not do the remediation. Welcome to lawsuit. How do you know that mold remediatino protocols were performed. The stains still there? somenthings up. When ever you see microbial stains and they follow up with cleaning, the mold assessor or Remdiation companyh provides warranties, you did not do the work, how can you warrant anything you do not do. Stay away or direct to a mold assessor for review to determine testing procedures or remediation procedures.


Sounds like a ‘Bleach’ job!
(Ask you wife how that works at the Beauty Salon)!


Is the seller that did the treatment qualified to evaluate and treat? Not likely. I always recommend having evaluated and treated by a qualified contractor. If that was not the case I would stay clear. Professional treatments are usually sealed with white paint after the treatment. But I have seen silver and even a clear coat used. Also I don’t see rafter vents to allow the soffit vents to function properly. Correcting the cause of the cause of moisture and increasing ventilation is also needed.


The IAC2 standards of practice are fairly clear. As a home inspector, you report what you see and possibly make a recommendation for further evaluation. Your done. As a Mold Assessment Consultant, here in Texas, I would come in perform a mold inspection, gather samples as necessary, and create a report based on the lab results. If mold is present, I would make a recommendation to consult with a mold remediator to discuss options. If they proceed with the remediation, I would follow up with a reinspection and provide a clearance letter based on the lab results. If the reinspection indicates that the remediation is incomplete, it becomes a warranty issue with the remediator and I reinspect until the lab says that the levels are not higher than the background levels. Fairly simple and straight forward.


The critical step that the Realtors and the sellers like to “omit”.

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So true. As a Mold Assessment consultant, my reports are primarily a slave to the labs and shipping times.

Dan Monroe



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Thank you all for the feedback.

Just for the record, as most of you had suggested, a home inspection is a visual examination, hence the question, ”what should mold treatment look like?” I had prefaced the inquiry acknowledging that presence of mold can only be done by testing.

Additionally, mold abatement is not a regulated profession in the State of Indiana, so treatment strategies vary.

Thank you again.

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