Thread: Mold on attic sheeting

I'm wondering how everyone else reports the visible mold on the attic sheeting. I know there are a couple schools of thought; visible mold growth should be mitigated and the other that it's not within the living space of the home and won't cause a health hazard.

Yes, I know about reporting the issues of insulation, ventilation, vapor barriers and bathroom / kitchen fans vented to the attic. I'm looking for information dealing with the visible mold.

Right now I'm writing it up as visible mold growth which should be evaluated by a qualified contractor. But, if it's not a health hazard, how else should it be written up?

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It's a judgment call. I tend to err on the cover my butt side knowing that most of the dark moldy looking sheathing at the lower edges is not a health or structural issue and can be addressed by improved ventilation. A moisture meter is handy. Provide pictures and defer to a qualified mold testing entity if the client has concerns.
I tend to be out of the "mold is way too often used as a scare word" crowd.
JLMathis

Good morning, Ken,
Absent of certification as a mold professional, I don't indicate that the visually perceptible biological or fungal growth on the surfaces of wood components is "mold". Jeff makes a good point that the "mold" scare is used too frequently. Noting moisture levels, if a meter is available, and looking at contributing factors (i.e., improper attic ventilation, improperly installed fan ducts, etc.) are much more beneficial to the client in determining suitability of the reviewed structure for their intended purposes. Then defer the option of having further review of the conditions to mold professionals or industrial hygienists.

Make it a great day!

Greg

Gregory L. Boso, PE
G. L. Boso & Associates, Inc.

Originally Posted by Greg Boso

Good morning, Ken,
Absent of certification as a mold professional, I don't indicate that the visually perceptible biological or fungal growth on the surfaces of wood components is "mold". Jeff makes a good point that the "mold" scare is used too frequently. Noting moisture levels, if a meter is available, and looking at contributing factors (i.e., improper attic ventilation, improperly installed fan ducts, etc.) are much more beneficial to the client in determining suitability of the reviewed structure for their intended purposes. Then defer the option of having further review of the conditions to mold professionals or industrial hygienists.

Make it a great day!

Greg

Gregory L. Boso, PE
G. L. Boso & Associates, Inc.

Greg;
I agree, usually the term "possible organic growth is visible" or, if you are a "certified mold professional" you might be able to say there is "possible or probable mold growth" but, without a lab test, I don't believe anyone can say for certain that it is mold without the lab test.
Again, ventilation and exhaust problems related to moisture accumulation is the main factor for mold growth as mold spores are always present in the air but without having the moisture available for continued growth, mold will not grow.

Visible staining on roof sheathing could be mould which results from excessive humidity and/or roof leak.

Laboratory testing is required to confirm presence of mould.

Providing a link to this site will provide helpful advice for your client.
Indoor Fungal Habits

Originally Posted by Ken Rowe

I'm wondering how everyone else reports the visible mold on the attic sheeting.

Depends... is it a little or a lot? Active or not active? Is a source of moisture present or not? Has it caused wood decay or structural issues?

If someone has mold, and it's a "problem", get rid of it.
If someone has mold, and the source of moisture can be mitigated and it's not problem - it should be no big deal - unless of course someone believes media hype over long lost biology facts. If that's the case you may need to educate the client.

Mold in Homes - EH: Minnesota Department of Health

Over the years, I have had dealings with a few qualified mold remediators. Over the past few years, none of them will serve a single family residential situation. Because most home owners get sticker shock and go away, the mold remediators restrict their business to commercial and institutional clients. Therefore, I choose to advise a client to solve their moisture, ventilation etc issues that are sustaining mold and not frustrate them with a referral that won't work for them.

It is true that if the moisture source is removed/corrected that the mold will go dormant. But even if the mold dies the spores are still present and can cause problems for people. Dormant or dead mold is a concern.

It may also be true that mold in the attic may not be problematic for people living in the areas below but ...... with exhaust fans in the bathrooms and kitchens, particularly the higher CFM units, the living areas can be depressurized thereby pulling attic air down into the home.

So while your client may be forgiving with mold in the attic the next buyer may not be and your client will have to deal with it then.

Much has been learned about mold in recent years yet without regulations the industry is full of contractors who have no idea what proper remediation entails. It's become a great line of work for Billie Bob.

Originally Posted by Darrel Hood

Over the years, I have had dealings with a few qualified mold remediators. Over the past few years, none of them will serve a single family residential situation.

In my experience the qualified remediators prefer to have someone write a plan for them to follow. I subcontract out to an IAQA certified indoor environmentalist and assist him in writing such plans. These identify the cause of the moisture problems and specify repairs. They also specify how to deal with the mold. All the contractor has to do is follow the plan - it leaves him with very few decisions to make and takes a significant burden off his shoulders.

Eric,
It appears that the process is similar in our two regions. However, down here enough home owners exit the process at the "quote step" that remediation consultants,
remediation technicians and qualified contractors are choosing not to participate in the single family residential market.

"I'm wondering how everyone else reports the visible mold on the attic sheeting. I know there are a couple schools of thought; visible mold growth should be mitigated and the other that it's not within the living space of the home and won't cause a health hazard."

I recently attended a 2 day mold assessment course and asked a similar question of the instructor. He said that mold in attic is 1) in the living space and 2) those attic mold spores can & will migrate to other areas of the home just like mold in the basement will also migrate throughout the home via air circulation, hvac, etc.

I've been asked multiple times over the past few years by clients if visible mold-like substances in the attic was a concern or not. I didn't know for sure and told them so, but recommended improvement in attic ventilation, venting of bathroom fans to the exterior, and mold testing by a professional to determine how the mold levels in the attic compared to those outside.

Indoor Fungal Habits

Originally Posted by dave koloskee

I recently attended a 2 day mold assessment course and asked a similar question of the instructor. He said that mold in attic is 1) in the living space and 2) those attic mold spores can & will migrate to other areas of the home just like mold in the basement will also migrate throughout the home via air circulation, hvac, etc.

I disagree that mold in the attic will migrate through the home just like mold in the basement. The basement, even if not finished, is within the living space. The attic is sealed off from the living space. If attic mold spore can migrate to the living space couldn't the same be said for fiberglass insulation particles?

If the ventilation of the attic is correct the mold spores should be traveling up and out of the home through the upper ventilation (roof, ridge). I can't imagine a scenario that mold in the attic can make it's way into the living space.

Originally Posted by Fred Comb

Depends... is it a little or a lot? Active or not active? Is a source of moisture present or not? Has it caused wood decay or structural issues?

If someone has mold, and it's a "problem", get rid of it.
If someone has mold, and the source of moisture can be mitigated and it's not problem - it should be no big deal - unless of course someone believes media hype over long lost biology facts. If that's the case you may need to educate the client.

Mold in Homes - EH: Minnesota Department of Health

Say for example the attic has a 1,000 square foot footprint and 1/3 of it has enough growth to make you want to report it. The shingles are new, no source of leakage, no rot and no structural issues. Ventilation appears to have been added recently. No sampling is done so we don't know if it's active or not.

Take into account that the Minnesota Department of Health does not recommend testing. If you see it, assume there is a problem and correct it.

While I see it as no big deal and it's not within the living space, I personally wouldn't worry about it. However, I don't want to be sued in 5 years when they go to sell their home and the next inspector freaks out.

Ken,

I've read all the posts on this thread and suggest that it is unlikely that the conditions you describe are anything OTHER than mold. Therefore, I write that such "conditions are consistent with mold and/or fungal growth." Further, I have generally changed all my recommendations to "best practice", so in these cases I recommend correction by a qualified mold abatement firm. I don't believe you will get in trouble for best practice recommendations. (The customer/owner can choose to do less.) Keep in mind that the type of sheathing and extent of the mold are important factors. If the sheathing is OSB and the mold is widespread, the "best practice" remedy will be removal and replacement of the OSB since the mold has penetrated into the wood flakes of the OSB and can not be "completely" cleaned or treated with a fungicide. Plywood has a similar but less severe limitation. No mold abatement short of sheathing removal can clean and treat the mold spores that are present on the TOP of the rafter or truss (covered by the sheathing).

I do not get into the issue of whether or not the mold spores will enter the house. The issue of damage to the sheathing is enough to trigger the recommendation. Further, the presence of the mold is clear evidence of attic bypasses (past or present) which are also a major heat loss from the house. Contact me if you want a referral to the Minnesota mold abatement professional I trust.

I'm not worried about whether or not to call it mold. MN Dept of Health gives authority for visual assessment, no testing necessary.

Originally Posted by Roger Hankey

The issue of damage to the sheathing is enough to trigger the recommendation.

What if there is no damage to the sheathing, other than the growth? Or are you saying the growth is the damage to the sheathing?

Originally Posted by Roger Hankey

...I have generally changed all my recommendations to "best practice", so in these cases I recommend correction by a qualified mold abatement firm. If the sheathing is OSB and the mold is widespread, the "best practice" remedy will be removal and replacement of the OSB ... No mold abatement short of sheathing removal can clean and treat the mold spores that are present on the TOP of the rafter or truss (covered by the sheathing).

I do not get into the issue of whether or not the mold spores will enter the house. The issue of damage to the sheathing is enough to trigger the recommendation.

Really? Who writes this Best Practice and where can I read it?

I agree. If I could look at something and tell if it is or is not mold, I could put the labs out of business.

Originally Posted by Phil Houck

I agree. If I could look at something and tell if it is or is not mold, I could put the labs out of business.

You're not in Minnesota so this doesn't pertain to you. But, Mr. Comb provided this link:
Mold in Homes - EH: Minnesota Department of Health

It states:

Home Investigation

How do I tell if I have a mold problem?

Investigate don't test. The most practical way to find a mold problem is by using your eyes to look for mold growth and by using your nose to locate the source of a suspicious odor. If you see mold or if there is an earthy or musty smell, you should assume a mold problem exists. Other clues are signs of excess moisture or the worsening of allergy-like symptoms.

• Look for visible mold growth (may appear cottony, velvety, granular, or leathery and have varied colors of white, gray, brown, black, yellow, green). Mold often appears as discoloration, staining, or fuzzy growth on the surface of building materials or furnishings. When mold is visible, testing is not recommended.
• Search areas with noticeable mold odors.
• Look for signs of excess moisture or water damage. Look for water leaks, standing water, water stains, condensation problems. For example, do you see any watermarks or discoloration on walls, ceilings, carpet, woodwork or other building materials?
• Search behind and underneath materials carpet and pad, wallpaper, vinyl flooring, sink cabinets, furniture, or stored items (especially things placed near outside walls or on cold floors). Sometimes destructive techniques may be needed to inspect and clean enclosed spaces where mold and moisture are hidden; for example, opening up a wall cavity.

I inspected a home 3 or 4 years ago that had "unidentified fungal growth" on roof decking in attic. Since it also needed new shingles, I verbally recommended new sheathing along with new shingles. Report recommended installing a bathroom vent fan ducted to outside and more attic ventilation.
Inspected the same home last month: New shingles, more attic vents, original sheathing, no exhaust fan, no mold.

I pick Roger, post #15. Best answer.

Unlike most of my southern brethern, I will go ahead and call mold mould when I see it. So what if you're not a trained pro? What do you call green fuzz growing on an orange or a piece of cheese? But I understand the law is strict in some states so in those states, you need to toe the line and give it a wishy washy monicker..

In an attic, not the living space, no pulldown stairs, if the 'fungal growth' is active, it will often be 3 dimensional and it will wipe off if you dare to touch it. Sometimes, the active areas will have a whitish or greenish tinge, and the dead cells will go black. That is the attic mold I am used to seeing. Those species seem to love cellulose and will certainly cause damage over time. Under some circumstances, I 'suggest' it can be washed off or sprayed with "Mold Killer". This is mainly to halt the immediate spread and hopefully reduce the growth to a harmless stain. Number one - find the moisture source and stop it.

Originally Posted by Fred Comb

Really? Who writes this Best Practice and where can I read it?

Ok, I accept the challenge even if posed with a little sarcasm.

I overstated a little about generally making "best practice" recommendations. Most of my recommendations on home inspections are non-specific and leave the details of the correction to the qualified contractor. I do not design the remedy or correction.

Ordinarily my recommendations are very general and don't discuss 'best practice". I might say for example: Have the attic corrected by qualified mold abatement and insulation firms.

I give "best practice" recommendations only in situations where I've seen the same or similar conditions before AND met onsite with qualified contractors or experts who came out evaluated and discussed the situation. A mold abatement contractor for example is the one who explained that unless the sheathing is removed, mold spores will remain between the sheathing and the top of the rafter or truss. This may not matter to some customers. Others may want the top of the rafter cleaned and treated.

I give "best practice" recommendations most often on consulations rather than on general home inspections. I'm doing lots of consultations now and less home inspections due to the seasonal decline in real estate transactions. If I give a more specific recommendation, it is because a range of choices are available for remedies. If there are multiple factors involved in the adverse condition, I like to be specific enough in the recommendation that all those factors are addressed. The customer can certainly chose to do less or hire a contractor who does less.

Attic insulation / ice dam cases are a great example. Attics with trampled blown insulation, multiple layers of insulation with unsealed bypasses, moldy sheathing, etc. are good candidates for a best practice remedy of removing the existing insulation before sealing bypasses and re-insulating. Qualified insulators have repeatedly told me this is the only way they can be sure that they will be successful in sealing all bypasses. Other insulators may claim they can work around blown insulation, but unless the old insulation is removed, finding and sealing ALL the air leaks is difficult. I don't believe I can find all air leaks covered by insulation even with my IR camera.

Other situations that may call for "best practices" recommendations include: how to remedy aluminum wiring, how to remedy an FPE electric panel.

When I give specific "best practices" recommendations in a consulation, I explain that other less comprehensive approaches are available, and that the customer is advised to have contractors explain, demonstate, and compare the performance of the less costly measures with the performance of a best practice approach.

I advocate writing your own best practice recommendations based on situations where you have learned from qualified contractors when their specific experience and knowledge supplements and compliments your experience and knowledge. Your attorney may also be able to provide guidance on how specific your recommendations should be based on the needs of the customer and the terms of your contract. Consultations are different than pre-purchase home inspections and often have different levels of specificity.

I hope this helps.

Originally Posted by Roger Hankey

Ok, I accept the challenge even if posed with a little sarcasm.

If there was sarcasm on my part, I apologize. None was intended.

Originally Posted by Roger Hankey

I overstated a little

Yes, I believe you did.

Originally Posted by Roger Hankey

I advocate writing your own best practice recommendations

I would encourage you to rethink this. Based on your "public" reply above it may be unwise.

Feel free to invite me to dinner someday and I'll be happy to explain in more detail. Perhaps when the Rainbow Room in NYC reopens?

I would put in a report. I noted a black sooty type material in the...., I highly recomedend having an applicable contractor evaluate and advise on this. This could be a potential health hazard to some people.

Originally Posted by Rolland Pruner

This could be a potential health hazard to some people.

Could it be a potential health hazard? If this were a health hazard, wouldn't fiberglass particles from the insulation also be a health hazard?

Has anyone used the mold test kits out there? & if so what is your recommendations, brand, & where to buy.

Why test? Treat all mould as bad.

Mould Testing: Is it beneficial or 'snake oil?'

Doug.. First take a class or two (not on line)

Testing equipment. Environmental Solutions Association | Your Indoor Air Quality Training Provider or PRO-LAB Laboratories - Mold Lab & Radon Lead Water Testing by PROLAB
you need a vacuum pump and spore traps or swabs/tape lifts.

If you are going to set out a pitri dish, be aware that there are 8 or 9 different mediums that different molds grow on. (not a professional type test - in my opinion)?

Also

Mould Testing Research Report

https://www.buildingscience.com/docu...mold%20testing

This weekend I saw an episode of This Old House in which a specialist used fancy equipment to blast a moldy attic sheathing with small dry ice pellets. It was impressive and I suspect very expensive. Weak bleach water would probably do as well.

Bleach is not recommended and it doesn't kill mold spores.

Raymond,
My point was not that weak bleach water is great. My point was that it is probably as good as the dry ice blaster thingamabob.

10-4.

Cheers,

OK, so you test for mold. Your client gets the results.
What's going to happen after you read the results?

Originally Posted by Raymond Wand

Also

Mould Testing Research Report

https://www.buildingscience.com/docu...mold%20testing

Great easy to read paper that stresses the importance of concentrating on inspecting for the sources of moisture infiltration which is allowing mold growth and not spending money on testing. Should be on all inspectors web sites. Will be added to mine shortly.
To continue the deviation from the OP, this brings up to me the question; as a home inspector, working for a potential buyer, how do you address to your client that it could potentially be a rather large cost to totally correct a mold problem when the extent of mold, the exact moisture source and method of correcting cannot be easily pinpointed and their agent would rather move on to the next house as opposed to working with the seller and their agent on undetermined price adjustments?

According to the link in post #6, the Minnesota Department of Health recommends the use of bleach.

Originally Posted by Darrel Hood

According to the link in post #6, the Minnesota Department of Health recommends the use of bleach.

You may want to be very careful about taking that comment out of context.

Fred,
You are right. One should always be careful about context. Paraphrasing the document:
Clean it with a non detergent non ammonia solution then sanitize using weak bleach water.
Thanks.

I had a client a couple weeks ago who said she was extremely allergic to mold and that her doctor didn't want her living in a house that has mold. I don't care if mold remediation is viewed as snake oil, bunk, a pack of lies, etc. I will recommend it as needed and play the game. I can't overcome years of sensationalized media reporting on mold in a few hours with a client. What the client chooses to do is up to them and out of my hands.

From what I gather, the problem with bleach isn't that it doesn't kill spores, it's that the spores are in the air, so no liquid-based treatment will ever work if the moisture problem isn't fixed. And with porous materials like OSB you can't kill anything beyond the surface without totally soaking it - then you have bleach left behind that itself can break down the lignin in wood, or once that evaporates, water (which of course promotes mold growth).

Bleach should not be routinely used to kill mold...nothing should be routinely used, as it suggests that the cause of the mold has not been addressed. Plus bleach itself is not good to breathe.

From the Center for Disease Control:
"Mold growth can be removed from hard surfaces with commercial products, soap and water, or a bleach solution of no more than 1 cup of bleach in 1 gallon of water." (CDC - Mold - General Information - Basic Facts)

Originally Posted by Gary Bottomley

To continue the deviation from the OP, this brings up to me the question; as a home inspector, working for a potential buyer, how do you address to your client that it could potentially be a rather large cost to totally correct a mold problem when the extent of mold, the exact moisture source and method of correcting cannot be easily pinpointed and their agent would rather move on to the next house as opposed to working with the seller and their agent on undetermined price adjustments?

I have a simple way to report the extent of mould in an attic. I give them 5 or 6 pics of the attic sheathing. If a bath vent is leaking a bit, there will be only one or two pics of a bit of stain around that one spot. "Fix the leaky vent pipe".
If there's a lot of mold, the client gets a lot of pics. Most people can figure it out from that.
I will suggest possible sources of the moisture, but if the source isn't obvious, I will recommend that they get professional help. Smart people will walk away.

We had Penicillium mold growing on our attic sheathing-we bought Concrobium at Lowes and rented a mold fogger at Home Depot-Worked great!! Total cost $60.00 plus labor- Saved thousands-on over 500 sq. ft of attic.

Oh, and Concrobium is odorless and non-toxic

Originally Posted by Susie Smith

We had Penicillium mold growing on our attic sheathing-we bought Concrobium at Lowes and rented a mold fogger at Home Depot-Worked great!! Total cost $60.00 plus labor- Saved thousands-on over 500 sq. ft of attic.

When you go to sell the house some day and the buyers want to know what was done about the mold problem in the attic a $60 receipt from Lowes likely won't put them at ease.

I'm not saying what you did is good, bad or otherwise... just thinking ahead from my experience in how buyers react to things.

Did you do any lab testing after the $60 mold remediation job?
Probobly not.
I suspect that after hearing that a mold problem was fixed for $60, a buyer would likely want some lab testing to confirm that the problem really is gone, not just hidden.

I have not seen the results of your project but if $60 really cured all the mold problems there would be thousands of mold remediation professionals out of work by the end of week.