Pre-Cleanup moldy basement framing Guide to Use of Fungicidal Sealants, Biocides, Sanitizers
Used on Building Surfaces or Carpeting

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This article discusses the best use of fungicidal sealants, biocides, fungicides, sanitizers, and mold paints or sealants to seal remaining free dust and to retard future mold growth.

We discuss the pros and cons of using fungicidal sealants and bleach on wood surfaces and give sources and list types of those products. We also discuss common errors made when cleaning wood surfaces, such as relying on bleach or performing expensive and unnecessary cleaning on cosmetic black mold on wood surfaces.

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3. TREAT & SEAL - cleaned building surfaces such as lumber or plywood - an optional step to reduce retard future mold growth

Spraying Anabec biocide on an interior carpet (C) Daniel Friedman & Anabec

This article series explains how to clean off or remove toxic or allergenic or even just cosmetic mold found on surfaces of un-finished wooden building materials such as framing lumber (rafters, floor joists, wall studs), and building roof, wall, and floor sheathing such as plywood, tongue-and groove pine boards, and other structural wood surfaces in buildings.

Our page top photo shows fungicidal paint sprayed on demolition debris in a building. The debris should have been removed before this sealant was applied.

At left the worker is spraying a sanitizer or biocide onto interior carpeting in a building.

Optionally, you may elect to treat cleaned lumber by coating its surfaces with a sealant intended for that purpose and following the recommendations of the manufacturer.

Applying Fungicidal Sealants after Mold Remediation

Photograph of sub microscopic debris and fiberglass insulation fragments encapsulated by a fungicidal sealant The mold remediator/cleaner may elect to apply a fungicidal sealant such as Fosters™ 4020 or 4051, the Anabec™ two-step cleaner-sealer system, or non-sealant fungicides may be applied in an effort to reduce the chances of future mold growth on the cleaned surfaces.

But readers should review the advantages and warnings about using fungicides and fungicidal sealants described next.

The photograph shown here was taken in our forensic lab during examination of a mold remediation clearance dust sample.

The photo shows how a clear fungicidal encapsulant (mold sealant) can encompass and immobilize small particles, in this case fragments of fiberglass insulation and sub-micron microscopic debris which were coagulated and encapsulated into now-solidified droplets of a clear commercial mold encapsulant/sealant.

ADVANTAGES - of applying a fungicidal sealant to retard future mold growth

Photograph of clear fungicidal sealant on building framing and subflooring This photograph, taken during a mold remediation clearance inspection, shows the use of a clear fungicidal sealant applied to previously-cleaned building framing and subflooring. The shiny coating makes evident where the coating has been applied.

The transparent nature of the coating permits the inspector, building owner, or a subsequent buyer of the property to view the quality of the cleaning job. Clear encapsulants have this advantage of showing the condition of the coated surface, assuring us that the mold remediator didn't simply "spray-over" a dirty moldy surface.

On the other hand, white or pigmented fungicidal paints and sprays are easier to detect, and it's easier to see if the application missed any surfaces that were supposed to be coated.

Good mold cleanup job (C) Daniel FriedmanOur photo (left) shows a moldy crawl space after expert cleaning, application of a clear fungicidal sealant on wood surfaces, and installation of a secure plastic barrier over a dirt and gravel crawl space floor.

Here are some advantages of using a fungicidal sealant following mold remediation

  • Sealants may reduce future moisture-uptake in wood, making it less quick to support future mold growth
  • The use of sealants after a mold cleanup project can immobilize particles left in hard to clean crevices
  • Fungicidal or microbial sealants contain a chemical which the manufacturers claim retard future mold growth. However the long-term chemical stability, thus the durability or "lasting power" of the chemical effects may be in doubt. I have been unable to find any long term study of the enduring effect of the fungicidal or microbial effect, and some studies, such as those done on microbially-treated fiberglass duct insulation indicate that the treatment is not long-lived.
  • The few remaining particles not removed by cleaning are immobilized - sprays and sealants are never a substitute for cleaning however.

WARNINGS - about using fungicidal sealants to control mold growth

Mold spray applied after cleanup (C) Daniel Friedman

Our photo (left) shows a white fungicidal sealant paint spray coating that has been applied to all surfaces in a building basement fas the last step in a mold cleanup project. The remediator did a great job of removing moldy materials, cleaning all surfaces, and leaving no demolition dust or debris in the building - all before this mold spray paint was applied.

  • Remember to clean: Fungicidal sealants or non-sealant fungicides should not be used as a substitute for physical cleaning of moldy or suspect surfaces and materials. Application of fungicides without cleaning risks leaving high levels of toxic or allergenic particles in the building.

    Even if a fungicide could "kill" every mold spore, which in our experience is unlikely, non-viable spores may still be toxic or allergenic. (See our page top photo).
  • Biocides or Fungicides which are not sealants have the same shortcomings as sealants and more: they are unlikely to kill 100% of their target, they do not immobilize remaining dust or debris on a surface and they do not provide future moisture resistance. At MOLD SPRAYS, SEALANTS, PAINTS we include recommendations for and against use of biocides in buildings - help in deciding when their use is or is not appropriate.
  • Possible health risks of fungicides and disinfectants: If your contractor is planning to use a disinfectant or fungicide on building surfaces be sure to review the chemicals to be used as possible irritants or hazards themselves. The remediation industry is of mixed opinion regarding the efficacy and advisability of using such treatments.

    Some people have allergic reaction to these chemicals. The contractor should be asked to provide documentation identifying the chemical(s) used, the concentration and manner of application, and the areas where they were applied, as well as providing pertinent health information from the manufacturer, as some occupants or owners may prefer to avoid these chemicals.

Mold Remediation Products, Fungicidal Sprays, Sealants, Biocides, Washes



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Frequently Asked Questions (FAQs) about Use of Fungicidal Sealants and Anti-Mold Coatings to Kill Mold or Prevent Mold Growth, including antimicrobials, biocides, and similar products

Question: what fungicide would kill ringworm spores in a garage

what fungicide would kill ringworm spores in a garage - Margery, 8/26/11


Margery, ringworm (dermatophytosis) spores can be airborne according to various experts, but my OPINION is that cleaning or removing the source is critical; trying to cure any airborne indoor air quality problem by treating the air is not likely to work - the particle source remains. For cleaning indoor surfaces an adequate disinfectant is needed. Vets comment that using a fairly strong Bleach solution (1:10 dilution), lime-sulfur dip (1:33) have a LIMITED ability to inactivate ringworm spores indoors. A vet we consulted suggested that Enilconazole, if available, can be used as disinfectant area fogger (Clinafarm SG—American Scientific Labs, Janssen Pharmaceuticals ) but WATCH OUT, this chemical is not approved for this purpose in the US. THOROUGH cleaning of all hard surfaces is key.

I would dispose of any soft goods that can be tossed. Some vets recommend steam cleaning carpets. My field and lab tests of mold spores (not ringworm spores) found in and on carpets and other thick fabric materials found that it would be a rare steam device that can produce enough volume and temperature to be effective in thicker materials


We are removing laminate flooring to install wood flooring. When we removed the underpad the subflooring has mold in several places. We do not even know how this came about. How can we clean the subflooring to remove the mold before laying down the wood flooring? Thanks. - Bill & Bonnie 10/2/11


Bill & Bonnie, any common household cleaner, even soap and water, work find for cleaning off mold from subflooring. Be sure the subfloor has dried before installing new materials over it. You shouldn't need to use a sealant.


I have repaired doors in a retirement facility and need to seal the exposed wood. The sealant needs to withstand bio-hazard cleaners. Any suggestions?

I am hoping you have some insight to a sealant that can be used in a medical facility that will withstand the hash cleaners used after an out break.

Andy - 11/1/11


Andy, we list a number of providers of biocides, sanitizers, and sealants in the article above and in the references at the end of this article. It would be most effective to ask your question to those folks directly to be sure that they understand exactly your requirements.

Question: we want a non slippery penetrating sealer that goes unnoticed after it dries.

We have a travertine pool deck and stairs approximate 2000 sq ft total.
Is there some products that we can use to inhibit future mold growth.
The difficulty is in that we are in Naples Fl and have approximate 5 months of rain every day.
we want a non slippery penetrating sealer that goes unnoticed after it dries. Kip 8/17/11



There are fungicidal sealants and paints that can work well on some surfaces provided the surface is clean and dry and sound first.

There are some clear sealants, but I'm afraid that in native form they'd be slippery.

Talk to the manufacturer about adding an anti-slip to those paints or sealants. In other words you may be able, with manufacturer advice, fabricate a clear sealant that includes an anti-slip additive.

Question: Have you examined the Aegis Microbe Shield technology from mPact?

Regarding Your text which I Quote from above --
"I have been unable to find any long term study of the enduring effect of the fungicidal or microbial effect, and some studies, such as those done on microbially-treated fiberglass duct insulation indicate that the treatment is not long-lived."

Have you examined the Aegis Microbe Shield technology from mPact?


We have not examined nor directly tested the product you name nor peformed chemical tests on any other sealant, biocide, or antimicrobial or sanitizing agent. We do, however, review documents and technical literature about these topics and products, and we do have field and lab experience in testing buildings for mold contamiantion before, during, and after various approaches to mold remediation.

When evaluating the effectiveness, claims, or promises of any product it is useful to distinguish between marketing literature, "white papers" produced by the product manufacturer, and independent, peer-reviewed authoritative studies. In some fields, such as septic tank treatments and perhaps in the area of mold treatments, these distinctions are particularly important.


Aegis Microbe Shield is provided by mpactworldwide [dot] com. The company's description (a video) of the product is interesting and it makes a compelling argument that the product, because it does not give up any of its coating material to a microbe that lands on the treated surface, works indefinitely. The product is described by the company as 99.9% effective against an extremely wide range of pathogens. Interestingly, the company also indicates that "Simple field-testing can quickly confirm the presence and continuing efficacy of our treatment."

"Indefinitely" is ... well, a time period of uncertain length and may not necessarily be taken to mean "forever". This helpful comment is offered by the company:

How long the technology continues to function is directly related to the life of the surface to which it is applied. In other words, while the technology may continue to fight germs indefinitely, the surface may be worn away, painted over or damaged, which would compromise the coating’s ability to function. Assuming that the surface is kept clean and not abused, our protection will last for the life of that surface. [5]

The product is described as a proprietary formula, meaning we don't know what's in it. We did not find, among the company's download-available documents, independent, scholarly or peer-reviewed studies testing the long term durability of its surface coatings or treatments, though the company's product description is indeed quite interesting. The company's website offers a study, examining skin absorption in rabbits, reporting on the safety of an antimicrobial that sounds like the one referred to in the company's promotional video: organosilicon quarternary ammonium chloride. [8] Other downloads document that certain of the company's products conform with Boeing or other standards. None of these documents discusses the questions of use of biocides in buildings, particulary as part of mold remeditaion, their proper use, efficacy, and long term durability.

We caution you that even if a biocide could "kill" every single mold spore (making the spores unable to germinate or grow on a surface in the future) you may be leaving toxic or allergenic particles in place. And our own field studies that sample sprayed or treated surfaces that had not first been thoroughly cleaned, often find viable as well as non-viable spores in the sample.

Finally, the best and proper mold remedy is to clean moldy surfaces, dispose of materials that cannot be effectively cleaned, and correct the leak or moisture problem that caused the mold growth. We have no objection in principle to ancillary use of biocides or other agents or cleaners to improve the process or to seal the surfaces to resist water uptake and thus retard future mold growth. But no spray or cleaner seems to be an effective substitute for doing the real work: clean the mold and fix the leak.

We are dedicated to making our information as accurate, complete, useful, and unbiased as possible: we very much welcome critique, questions, or content suggestions for our web articles. Working together and exchanging information makes us better informed than any individual can be working alone. InspectAPedia is an independent publisher of building, environmental, and forensic inspection, diagnosis, and repair information provided free to the public - we have no business nor financial connection with any manufacturer or service provider discussed at our website.

Question: fighting ringworm - do I have to get rid of every spore in my home?

After fighting ringworm for three monthes on our dogs and one cat plus ourselves which we contacted from a rescue kitten I have come to the conclusion that constantly cleaning your whole house, basement car, garage and clothes with bleach is an imposible task which will drive anyone crazy.Easier said than done.So if you get this scourage be prepared to live with it forever or move.You will lose all your friends and reletives with or without pets because they hear the word "ringworm "and head for the hills.My doctor says it's no big deal unless you live in a damp dark cave but the vet thinks it's the end of the world.You can't get rid of every spore and all it takes is one to re infect you?So what to do?If there is a hell i'm in it. - Carol Clark Hill 11/12/2012



I suspect the term "spores" is misleading here - as typical airborne mold spores likely to be found in a home are not the same sort of fungal spore as the cause of ringworm or dermatophytosis. Ringworm, which can infect humans and other animals is caused by the fungus Tinea and might be spread by direct contact, not by air. More details are provided by the U.S. CDC [20]

The object of removing every single airborne or surface-dust mold spore from a building is, frankly, silly. The moment you open a door or window, spores enter from outdoors.

Once a buildng has been properly cleaned of a known problem reservoir, no such heroic measures are appropriate.

We understand your concern, as ringworm is an upsetting and contaigous infection - when I was a kid the animals on our farm suffered as on occasion did we. It was cured by seeing a doctor. Your doctor is right on target in my opinion. And the CDC agrees, stating

Dermatophytes can live on moist areas of the skin, on environmental surfaces, and on household items such as clothing, towels, and bedding.

and ...

Ringworm is transmitted from direct contact with an infected animal's skin or hair. [20]

Once you've cured ringworm and cleaned wet shower floors etc, beyond normal cleaning and keeping an eye on your pets' health, take a look at our article on


for help with setting and maintaining an appropriate indoor humdity. If your vet is telling you you can get ringworm by air transmission of a fungus s/he is mistaken.

Question: hurricane Sandy flooded my sub-basement dirt floor - should I put down chemicals?

I had a flood in my sub-basement during Sandy. The sub-basement was professionally dried and cleaned. Do I have to put some chemicals into it just to be on a safe side? The floor is dirt - Jate 11/17/2012



If the sub-basement was properly cleaned and dried, adding more sanitizers or chemicals should not be necessary, though there are some advantages to

- using a fungicidal sealant on exposed wood surfaces to reduce future moisture uptake

- putting down plastic over the dirt to keep moisture from migrating into the building

See these articles


for a complete list of suggestions on how to clean up & dry out a wet or flooded crawl space.

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