White Powder on Floor Joists, mold or not?

Originally Posted By: AC Kelley
This post was automatically imported from our archived forum.



Three year old home. Until recently the only vapor barrier in the crawl was gravel. Three vents, open in the summer, closed in the winter. Not a lot of cross ventilation.


I am noticing some white powder on the floor joists. There has never been standing water or leaking pipes. The crawl space is in very good condition it seems to me. The substance really does not have the appearance of mold, but who knows. Not on all joists. It is streaky, not really in globules. It reminds me of the type of particulate left after condensation on metal. No pest or insect problems to speak of.

Is this mold? If so, my plan is to wipe away the problem areas with a mixture of bleach and water.

As of one month ago, there is now a plastic vapor barrier covering the gravel and a foamy (sprayed) insulation covering the block outer walls of the crawl. Possibly going to sell the home in the near future. Suggestions?


Originally Posted By: Caoimh?n P. Connell
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Hello AC Kelly:


The first question is: So, if it is mould, then why do you think it necessarily is a problem?

Let me give you a good example ? I was involved in a case wherein the property owner of the home had a mould ?expert? perform air monitoring and they found that the air in the home contained mould. The mould ?expert? also found about 2,000 square feet of mould on the floor joists in the crawlspace. The ?expert? recommended massive remediation of the crawlspace which eventually was performed at a cost of $36,000. The mould in the crawler was sanded, bleached and the wood sealed. The property owner then attempted to sue the home builder for the cost of the remediation.

Final post-remediation air sampling revealed that the air samples contained the same amount of mould spores in the air after the remediation as before. In the end, the property owner lost the suit and ended up not only footing the bill, but also forking out huge legal fees.

Why did they loose?

Simple, the mould in the crawler was not a "problem." The airborne spores found in the house were at normal concentrations for any similar home the area (several hundreds of spores per cubic meter of air) and the mould in the crawlspace was not a significant contributing factor for the mould spores in the air in the house.

Since the crawlspace could not be used for storage, there was no other exposure potential for the mould in the crawler. In the end, the homeowner could not successfully articulate why mould on the floor joists which could not bee seen, did not compromise the integrity of the wood, and did not constitute a significant contributor to mould exposures was a ?problem.?

In any event, I would certainly not recommend using bleach, since that certainly could cause some problems. Lastly, the installation of the vapour barrier, in the absence of a valid reason for its installation, could actually create new moisture problems where none otherwise existed, but reducing the hygric buffering capacity of the structure (amongst other things) and could increase the potential for mould growth, where none existed.

Just my take, as an expert witness in the subject matter, (and an expert on the above mentioned project) with over 15 years experience in mould assessments in properties.

Your thoughts are welcome. You may find my web discussions interesting:

State of knowledge on indoor moulds:
www.forensic-applications.com/moulds/sok.html

Air monitoring for moulds:
www.forensic-applications.com/moulds/mvue.html

Cheers,
Caoimh?n P. Connell
Forensic Industrial Hygienist

(The opinions expressed here are exclusively my personal opinions and do not necessarily reflect my professional opinion, opinion of my employer, agency, peers, or professional affiliates. The above post is for information only and does not reflect professional advice and is not intended to supercede the professional advice of others.)

AMDG



Originally Posted By: apfaff
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what Caoimhin has stated is correct but doesnt answer you questions. I think that your approach is correct. The crawl space will have some moisture and all substances can have mold spores and growth on them. I’ll let some of the southern crawlspace experts speak of the ventilation and insulation issue. Taking the steps you spoke of should help reduce the moisture, and reduce the likely hood of mold growth.



Aaron Pfaff


http://www.dedicatedhomeservices.com/


http://www.independentinspectors.org/wisconsin.html

Originally Posted By: ecrofutt
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No wonder I’m in the DDMG.



Erby Crofutt


B4U Close Home Inspections


Georgetown, Kentucky



www.b4uclose.com

Originally Posted By: AC Kelley
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So, then would you suggest cleaning the joists of apparent growth (if that is what it is), or not?


And, should I remove the plastic vapor barrier or leave it?

OR

Not do anything, and if I end up selling my home, let an inspector take a look. If they suggest a course of action, then do something about it.

To throw in another twist, I found what I think is mold in one of my air ducts in the lower level of the house. The air ducts are accordian style, attached to the boot with a zip strip. I don't see how moisture would have gotten inside the duct. There is condensation on the metal boot, but I don't see how it could have gotten in there.


Originally Posted By: Caoimh?n P. Connell
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Hello AC Kelly ?


Last week construction guys finished the construction of a deck on my home. They installed floor joists that already contained mould. That is very common, and not normally a problem. I would suspect that if someone paid me for the study, we would find mould, to some degree, on every floor joist installed in every house in the country (including floor joists that had just been ?bioremediated,? wiped clean and bleached).

Therefore, the question isn?t ?Is mould present?? but rather, the question becomes: ?Is moisture present that could result in a proliferation of vegetative growth of mould.?

Every house has the capacity to ?soak up? and hold finite amounts of water before that water reaches a point where it is available for use by fungal entities; this is known as the ?hygric buffer? of the structure. By installing vapor barriers where one isn?t needed, and by covering concrete/block walls with sealant can decrease the hygric buffer, creating a moisture problem in a structure that was otherwise OK, and leading to a moisture problem leading to mould growth.

In your case, you stated that the crawlspace looked to be in pretty good shape prior to the installation of the VP and the spray foam ? and therefore, it probably was in good shape and didn?t need any adjustments. Why was the VP and foam installed, by whom and what was the rationale supporting their conclusion it was needed? Unless there were very specific reasons for installing the VP and the foam (other than myth), their installation may have sufficiently lowered the hygric buffer capacity and increased the moisture leading to the appearance of the new white material which may be mould (or the white material may have already been there... I haven?t got a clue.) However, in general, soils and concrete are great sinks for soaking up lots of extra water. Blocking those pathways means the water has nowhere to go (of course in some problem houses, there is an unacceptable source of water flowing through the foundation walls, and soils which if landscaping does not correct needs to be addressed and sealing those surfaces sometimes is appropriate).

You say ?To throw in another twist, I found what I think is mold in one of my air ducts in the lower level of the house.? You have mould in ALL of the ducts in your house (just like all of the ducts in my house, your doctor's house, your kid's school and all other houses in the country). Indeed, you have mould on most surfaces in your home. Again the question isn?t ?It is there?? to which the answer will invariably be ?Yes,? but rather, what is it?s significance and is there a moisture intrusion problem that will permit the proliferation of the organisms. Take a look at my duct cleaning discussion at http://www.forensic-applications.com/moulds/ducts.html for some additional information on ducts.

In general, without moisture a moisture problem (past or present), there is no mould problem. What is the foundation for your fears concerning moulds and did you get a chance to read my web discussions on health effects and indoor moulds?

Cheers,
Caoimh?n P. Connell
Forensic Industrial Hygienist
www.forensic-applications.com

(The opinions expressed here are exclusively my personal opinions and do not necessarily reflect my professional opinion, opinion of my employer, agency, peers, or professional affiliates. The above post is for information only and does not reflect professional advice and is not intended to supercede the professional advice of others.)

AMDG



Originally Posted By: AC Kelley
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Your question as to why I added the vapor barrier and insulation to the block walls.


There is the distinct possibility that I may be trying to sell my house and move to another job in a different city. As a result, I started thinking about all the things that might need to be done to the house to make it ready for sale.

I called the city/county engineer about the crawl space, and he said that they are encouraging the home builders in the area to have a vb and insulation. I called the home builder and asked him if it was supposed to have been done. He indicated that it was probably supposed to have been done, and just never got done. He said that he would have it corrected.

That is when I started to get a little nervous about the floor joists, air ducts, attic, etc. I don't want a home inspector to come in and tell me I need to have all this work done, which I cannot afford, in order to sell my home.

In the end, if we don't end up selling the house, I still want my living environment to be as safe as possible for my family.

One thing I would recommend to someone who is prone to be anxious about this stuff is not to get online and read all the info about mold. It just freaks me out!


Originally Posted By: Caoimh?n P. Connell
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Fair enough, fair enough.


Some years ago, during the fever pitch of the mould scare, some municipalities issued building codes that arbitrarily required VBs and even mechanical ventilation of crawlspaces. In some cases, the municipalities solicited opinions and positions from the Industrial Hygiene profession; however, when it was seen that Industrial Hygienist?s positions were quite contrary to developing public myth concerning residential mould and the physics behind moisture, the municipalities decided that we were a bunch of kooks and ignored our input. After all, EVERYONE knew mould was toxic, and VBs ALWAYS reduced moisture, and ventilation ALWAYS removed moisture - so what do these nutzy scientist guys know, right?

It didn?t take long for the same municipalities to realize that their new building codes, intended to mitigate moisture and mould, actually created more moisutre and mould problems than they solved. The effects were profoundly seen in some homes that were up to 50 years old, and which never had a mould problem until the retro-installation of a VP and forced crawlspace ventilation.

Good luck with your move, and for the moment, I would think that you probably are worrying for naught. Perhaps, it would be more constructive to ignore the whole issue for a while and see what happens? I dunno, just a thought. I think the Home Inspector guys are more competent than an industrial hygienist on this aspect and I will defer to their superior advice.

Cheers,
Caoimh?n P. Connell
Forensic Industrial Hygienist
www.forensic-applications.com

(The opinions expressed here are exclusively my personal opinions and do not necessarily reflect my professional opinion, opinion of my employer, agency, peers, or professional affiliates. The above post is for information only and does not reflect professional advice and is not intended to supercede the professional advice of others.)

AMDG



Originally Posted By: apfaff
This post was automatically imported from our archived forum.



Caoimhin,


I follow what you have been saying in this, and all of your other posts as well as your website with great interest. I am a novice inspector and devour this type of information in great amount each day to better my understanding of the issues involved as it relates to home inspecting and try to couple that with practical knowledge. I thank you for your insight on these subjects, and agree with the vast majority of your statements.


The problem I see as it relates to HI?s is we are caught in the middle were we cannot possibly test to the extent it would require to stand up in court or to the scrutiny of the scientific community. We have to report ?mold like substances observed? and ?moisture damage can have other effects related to mold?? I think we are all in the same boat when it comes to many of the issues but we are supposed to be the intermediates to the public and the scientific realities of these environmental issues.

I can only do so much when it comes to reporting and try to avoid litigation by overstepping my professional bounds, but I am also subjecting myself to liability if I do not say anything. Your positions are from a strict scientific background, and you do make practical concessions, but we cannot go against majority conventions, or stand on a puritan principal when trying to report condition of a structure. We have to go with the industry standards and conventions whether it is supplied by the EPA or the building industry.

I enjoy your wealth of knowledge of environmental subjects, and will always defer to the experts for further analysis. Keep it coming.


--
Aaron Pfaff
http://www.dedicatedhomeservices.com/
http://www.independentinspectors.org/wisconsin.html

Originally Posted By: Steven Brewster
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Interesting topic… Took these photos yesterday. Home is 100 year old, dryer vents into crawlspace near this area, minimal ventilation, joists in close proximity of the soil, no barrier. I’d hate to be the service pro that has to work in this area. Got Mold??? You bet. My concern is long term effects on the integrity of the joists…


[ Image: http://www.nachi.org/bbsystem/usrimages/P/P1010567.JPG ]


[ Image: http://www.nachi.org/bbsystem/usrimages/P/P1010571.JPG ]


[ Image: http://www.nachi.org/bbsystem/usrimages/P/P1010573.JPG ]


Originally Posted By: Caoimh?n P. Connell
This post was automatically imported from our archived forum.



Mr. Brewster:


Great photos, and actually very telling. This precisely the growth distribution we see with mechanical ventilation in crawlspaces, wherein warm ?dry? air from the outside is drawn into the cooler crawlspace. When the temperature in the crawler is below the dew point of the incoming air, condensation occurs and the ?available water? (Aw) on surfaces increases ? poof! ? growth.

From the photos, it is impossible to say with confidence if the mycelia have invaded the deeper portions of the wood to the degree necessary to compromise the integrity of the wood, but it doesn?t appear to be that way.

Mr. Pfaff ? you are so right. In my area of industrial hygiene practice, I am permitted to entirely buck protocols, such as the EPA protocols, NIOSH and even OSHA and not get into deep water. So my discussions do come from a very different liability perspective; which is precisely why I chose to participate in a board which is so very much different than my field; to offer (and receive) a different perspective.

I have learned a lot from the discussion among the HIs on this forum.

Cheers,
Caoimh?n P. Connell
Forensic Industrial Hygienist
www.forensic-applications.com

(The opinions expressed here are exclusively my personal opinions and do not necessarily reflect my professional opinion, opinion of my employer, agency, peers, or professional affiliates. The above post is for information only and does not reflect professional advice and is not intended to supercede the professional advice of others.)

AMDG



Originally Posted By: AC Kelley
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The white substance in the pictures that Mr Brewster supplied is similar, but I have nowhere near the amount of dispersion or growth. Mine looks more like what you see in the third picture.


However, my crawl space is in much better shape than the one picture. Probably 2 - 3 feet of clearance, plumbing and HVAC all very neat and contained, very little debris (a board here and there).

I wanted to attach a link to a post I sent to another "expert" on this subject to get your thoughts on what they had to say. Here is the link:

http://www.charlotte.com:80/mld/charlotte/living/ask_expert_front.html?forumId=1514

My post is the second one.


Originally Posted By: Caoimh?n P. Connell
This post was automatically imported from our archived forum.



AC Kelly:


Regarding your response from the ?expert?- Considering the abundance of hyperbole, and the lack of actual facts in some of their statements ? I would say they are "experts" alright ? but not expert in mould, fungus or radon, or any other related issue.

Anyway ? their comment that you are detecting live moulds spores through odour is pretty amusing. And I would love to see their foundation for coming up with such a fantasy and what is almost certainly entirely incorrect! If you have the ability to detect live mould spores through your keen sense of smell - all your troubles are over - you will make millions $$$ selling your very unique service!

Cheers!
Caoimh?n P. Connell
www.forensic-applications.com


(The opinions expressed here are exclusively my personal opinions and do not necessarily reflect my professional opinion, opinion of my employer, agency, peers, or professional affiliates. The above post is for information only and does not reflect professional advice and is not intended to supercede the professional advice of others.)

AMDG



Originally Posted By: bkelly2
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This would be pest control territory here in AZ as the laymans term would be white dryrot, not to be confused with the evil twin brown dry rot.


http://www.buildingpreservation.com/Rots.htm


--
"I used to be disgusted, Now I try to Be amused"-Elvis Costello