Re: Ask Dr. Burge: Can We Use Heat to Remediate Mold Contamination?

[Guest guest]

,When you say 'not detectable' you are talking about spore tests, QPCR, volume air sampling for mycotoxins, human reactions being caused, or what? What kind of detection? This is really important.

By virtue of the fact that they are dependent on spores, microscopic spore testing is only going to show mold in cavities where the gaps allow the larger particles to pass through them to wherever the testing is being done. However, studies I have seen have proven that smaller particles, under 1 micron - can pass much more freely than the discussion here seems to be acknowledging. And of course, that they can carry a significant amount of toxic load. And those are also the particles that can be respired the deepest into the lungs.

For people who have asked - and paid for 'mold remediation', even tiny amounts of those microparticles could quite possibly be a serious problem, especially if there was a serious mold problem in one of those hidden cavities.. (stachybotrys, etc. which doesn't like to show up on spore tests even under ideal conditions..) If there is a serious problem in one of thise cavities, its quite plausible that the amount of toxicity that is leaking into the habitable space of the dwelling is high enough to make people sick.. even mold naive people who were not sick previously. Given a few years, some will get sick.. especially if something like an earthquake or building settling opens up those holes..

That is why in SERIOUS mold situations, IF there is NOT a will to explore those potential hidden cavities and CLEAN THEM OUT before considering a job finished, then gutting to the studs and cleaning or demolition and rebuilding may be the ONLY alternative that will work, since it is not practical to heat buildings to 500 degrees for 30 minutes like the Army says needs to be done to inactivate trichothecenes..

Just my $0.02 as someone who has had to deal with this situation..You can't *avoid maintenance for 30 or 40 years* AND *then expect a Band Aid solution to clean up the mess*.. Which seems to be what some people here are trying to say..

That might be enough to get paid.. but as far as solving a problem long term, permanently, I sincerely doubt that it would work in some situations.. like the one I left..(The insides of the walls were covered with mold)

[Guest guest]

CIEC_Fl

Managing mold in place will/can allow for

re-growth. Mold that has been formally active no longer needs large amounts

of moisture. It can be reactivated with simple vapor elevated conditions i.e.

like Florida

or a humid period of days (like last summer in the north east). Now that you

have decided to manage the mold in place, can you guarantee you will further manage

it by periodically revisiting the managed mold(s). Will you simple just leave

that up to the owner who barely has time to go to the store for milk?

One may argue that there is mold

everywhere so what is the difference? When the mold has become an issue

(that is most likely why you are there) than managing it is not an option in my

book. At that point, it was managed (naturally).

The home is their greatest asset, let’s

give them good information, let them make the decision and not just make money

off them saying they can’t afford the right protocol so I will dummy it

down knowing it has a great potential of reoccurrence. I have had some owners

say they cant afford it just so you will keep the bill down. If they want it

done unprofessionally, I will walk away. Not as to not be willing to help them,

but when something goes wrong and they are in survival mode I will not be

at the end of their attorney’s short (recovery) list.

I think one is forgetting the main issue,

find the moisture souse and mitigate (or manage) it.

Secondly remove the repercussions of the elevated

moisture conditions. Remember, it is not suppose to rain inside therefore water

indications should not be growing inside. As well, keep in mind, mold spores

are ubiquitous although should not be growing indoors. If they are not growing

indoors there should not be less than outdoors (where it rains). As well the

species inside should be equal (wind blowing all windows open) or less than (most

often/likely) due to building assemblies acting as a filtration system

(exterior walls – insulation) and static pressure (fire blocking, top and

bottom plates, etc) as related to outside air migrating inward.

I feel its best to manage moisture/water,

remove mold.

My attorney once told me the most

expensive ends up the cheapest and the cheapest ends up the most expensive.

Bob/Ma.

From: iequality [mailto:iequality ] On Behalf Of ciec_fl

Sent: Tuesday, January 23, 2007

10:51 AM

To: iequality

Subject: Re: Ask Dr.

Burge: Can We Use Heat to Remediate Mold Contamination?

, like yourself, I 've seen many folks not be

able to afford a

proper remediation despite paying enormous homeowners insurance

premiums (Florida)

for little or no coverage. And, some of our

retires, already frail, have -0- homeowners insurance as they also

have -0- mortgage, but despirately need every available dollar for

prescriptions & other forms of health care.

It would be wonderful if a 'managing in place' solution could be

found. Of course, this assumes correcting the source of the moisture

at the outset. Unlike asbestos that will stay out unless one brings

it back into the structure, mold is an uninvited guest that will

move-in on any host that will provide it with ripe conditions.

That said, one of my concerns (Florida

- Hot-Humid) is modifying the

permeance of the wall assembly, which I feel might happen with a

skin application. In Hot-Humid, we must have walls dry to both sides.

Obviously to all on this board, it would be great to solve the

problem with positive pressurization, but that is more often than

not extremely costly. It is also virtually impossible in many

buildings.

What kinds of other methods do you fell may offer hope? I may be

missing many. Thanks in advance, ~Cheryl

[Guest guest]

The ability of a particle to move with air flow is best described by its (various) aerodynamic diameter (s) [the area is finally used, not the diameter] and it mass (weight will do). Many mold spores have aerodynamic diameters that are larger than their physical diameters, making them more likely to "go with the flow." Fibres such as glass and mineral wool have a low effective or aerodynamic diameter in one direction and a larger one when trying to move long-axis to the flow. Unfortunately they are then prone to sticking into obstructions in narrow gaps. The complexity of flow paths in housing constructions makes an almost-spherical particle more likely to get out of a cavity than a long fibre (compared to its length), or any elongated particle. So, in reality, many mold particles do preferentially move out of cavities compared to fibres or other particles.

A point that you should remember is the extreme variability of housing construction on this continent. It is only recently that the Canadian National Building Code (NBC) specifically required an air barrier for energy purposes. There is still no real building code requirement, at the national level, in the US. For years we have had vapor barriers (bad idea, they should be retarders, not barriers) in both our sets of codes, but in most of Canada most houses would survive very well without a vapor retarder other than materials and finishes already there. That is not true for many US locations. All quality housing should have at least tow air barriers (where the intent is to stop air flows, not just reduce them, but this is not even effectively communicated in the Canadian model NBC and is not effectively there at all in the US codes. You and I both know that good construction requires an air barrier. Most builders do not believe in them, except locally.

In spite of my unofficial status, I am hoping to get better construction advice in codes and practice up here in the long term. It should not cost a fortune to build well, but the industry associations here say that improving standards would make all housing unaffordable; something that they often do if any small or large change is suggested. Unfortunately we have not been building test houses to show they are wrong (don't want to upset them, or something). CMHC is presently pushing through a large demonstration/study of Net Zero Energy Healthy Housing and it will hopefully show that the total cost of very good housing is not all that much different than present housing; although the money may be spent of different things and in different timeframes.

Jim H. White SSC

Re: Ask Dr. Burge: Can We Use Heat to Remediate Mold Contamination? :This is my point also, i.e., why can’t mold be managed in place? It was managed in place prior to 1995 when mold wasn’t such a big deal and before the media blew it out of proportion. The source advocacy folks say mold must all be removed; which is hog wash! If all mold was removed, we could state that the structure was sterile of mold; which is impractical, unrealistic, and hog wash. No matter how hard a remediator works to remove mold, without demolishing the structure into its functional components, all the source cannot be removed. And until the source removal folks accept and acknowledge this, we cannot have a meaningful discussion of what to do next, e.g., use heat to kill what remains. I, for one, believe that Dr. Burge made some factual errors and omissions with what she wrote, and I am preparing a letter to her. I will share my letter and her response with this group, if and when I get a response.For what it is worth....-- Geyer, PE, CIH, CSPPresidentKERNTEC Industries, Inc.Bakersfield, Californiawww.kerntecindustries.comOn 1/19/07 1:15 PM, ", " <robert.williamsladwp> wrote:

Group, I understand Dr. Burge’s point, if mold is killed by heat it may still have toxic properties and be an allergen, but a corollary can be drawn concerning asbestos containing material such as floor tile. Often asbestos containing floor tile is left in place and covered by non-asbestos containing flooring. This is called managing asbestos in place. If the asbestos is covered and cannot become airborne it is not a hazard as long as it is not disturbed. This has been the standard practice of managing asbestos in place for many years and is approved by OSHA & the EPA. Asbestos causes asbestosis, lung cancer and mesothelioma. Is mold that toxic? I don’t know. Why can’t we manage mold in place? This is just food for thought. I know this is contrary to the way mold is handled, but why? I know this is going to cause a firestorm but I believe this issue has to be aired. , MS, CIH, CIEC -----Original Message-----

[Guest guest]

Bob, You're preaching to the choir, and I'm sure that you were not

trying to be insulting. To the obvious points you made, I'll add -

" What happens when the structure looses electric service? " That's

usually during/following a severe weather event including rain - all

mechanical dehummidifications systems stop running and + pressure is

lost.

That said: It would be great if we were able to think out of the box

and stretch to find an affordable way to tame the monster in the

future. I that was the intent of the post.

~Cheryl C Crane

[Guest guest]

Cheryl:

The general rule regarding vapor barriers/retarders is:

In a hot/humid climate, the vapor retarder should be on the exterior side of the wall assembly which will allow the wall to dry to the inside.

In a cold/dry climate, the vapor retarder should be on the interior side of the wall assembly which will allow the wall to dry to the outside.

In all other climates.....it depends. And, if you are going to install a vapor retarder in the walls, it also needs to be in the roof/ceiling, or the attic suffers from excessive water vapor/condensation.

For what it is worth.....

On 1/23/07 7:51 AM, " ciec_fl " <no_reply > wrote:

, like yourself, I 've seen many folks not be able to afford a

proper remediation despite paying enormous homeowners insurance

premiums (Florida) for little or no coverage. And, some of our

retires, already frail, have -0- homeowners insurance as they also

have -0- mortgage, but despirately need every available dollar for

prescriptions & other forms of health care.

It would be wonderful if a 'managing in place' solution could be

found. Of course, this assumes correcting the source of the moisture

at the outset. Unlike asbestos that will stay out unless one brings

it back into the structure, mold is an uninvited guest that will

move-in on any host that will provide it with ripe conditions.

That said, one of my concerns (Florida - Hot-Humid) is modifying the

permeance of the wall assembly, which I feel might happen with a

skin application. In Hot-Humid, we must have walls dry to both sides.

Obviously to all on this board, it would be great to solve the

problem with positive pressurization, but that is more often than

not extremely costly. It is also virtually impossible in many

buildings.

What kinds of other methods do you fell may offer hope? I may be

missing many. Thanks in advance, ~Cheryl

[Guest guest]

,

I understand that one can never remove all mold from an environment. But I am not so certain it is wise to make a broad, general statement that it is acceptable to leave mold within wall cavities. I would venture to bet that if you posted your last message (see below) on the Sickbuildings website, you would get an earful back. Many on that board who are very ill, had a difficult time understanding what was causing their illness because there was no visible mold growth in their indoor environments. A good number of them are sick from mold that was hidden.

What to do with wall cavity mold, is an area that could really use further clarification and an understood industry standard of when to address and when not to.

Sharon

If a small amount of mold is hidden inside a wall and there is no moisture source and it is not detectable (spores or odor) in the living space, a good case would be to leave it where it is. Wall cavities are not living space. As someone that has inspected many, many homes under construction, there are not any new homes built that are mold free inside of wall cavities or inside of attics. And there are certainly no older homes that are mold free inside of walls and in the attic or other crawl spaces that are exposed to outside air.

You won't find any spec anywhere that says you have to remove mold inside wall cavities that is not detectable within the home.

Let's use some common sense here.

Rosen

[Guest guest]

, Thanks for your reply.

What you offer as generally true is correct for frame construction.

However, generally, we build with CMU's in Florida.

CMU walls in Hot-Humid need to dry to both sides. Therefore, latex

paint is preferred over elastomeric, etc. Foil faced insulation on the

inner side, and polypropylene should be avoided in favor of semi-

permeable ridged insulation w/ permeable skins (wood furring applied

over insulation, gwb, latex paint to complete the assembly).

You are right on with frame construction, but we're mostly block. I

failed to mentioned that in my post. ~Cheryl

[Guest guest]

I wish that I had inserted an " & " between mechanical &

dehumidification. Thank you in advance for ignoring this error. ~Cheryl

>

> Bob, You're preaching to the choir, and I'm sure that you were not

> trying to be insulting. To the obvious points you made, I'll add -

> " What happens when the structure looses electric service? " That's

> usually during/following a severe weather event including rain - all

> mechanical dehummidifications systems stop running and + pressure is

> lost.

>

> That said: It would be great if we were able to think out of the box

> and stretch to find an affordable way to tame the monster in the

> future. I that was the intent of the post.

>

> ~Cheryl C Crane

>

[Guest guest]

All,

is correct ... but practically speaking the proper was to re-install any barrier or insulation is to put back exactly what was taken out.... not to make any changes.

Rosen

Re: Re: Ask Dr. Burge: Can We Use Heat to Remediate Mold Contamination?

Cheryl:The general rule regarding vapor barriers/retarders is:In a hot/humid climate, the vapor retarder should be on the exterior side of the wall assembly which will allow the wall to dry to the inside.In a cold/dry climate, the vapor retarder should be on the interior side of the wall assembly which will allow the wall to dry to the outside.In all other climates.... .it depends. And, if you are going to install a vapor retarder in the walls, it also needs to be in the roof/ceiling, or the attic suffers from excessive water vapor/condensation.For what it is worth.....On 1/23/07 7:51 AM, "ciec_fl" <no_reply@yahoogroup s.com> wrote:

, like yourself, I 've seen many folks not be able to afford a proper remediation despite paying enormous homeowners insurance premiums (Florida) for little or no coverage. And, some of our retires, already frail, have -0- homeowners insurance as they also have -0- mortgage, but despirately need every available dollar for prescriptions & other forms of health care.It would be wonderful if a 'managing in place' solution could be found. Of course, this assumes correcting the source of the moisture at the outset. Unlike asbestos that will stay out unless one brings it back into the structure, mold is an uninvited guest that will move-in on any host that will provide it with ripe conditions.That said, one of my concerns (Florida - Hot-Humid) is modifying the permeance of the wall assembly, which I feel

might happen with a skin application. In Hot-Humid, we must have walls dry to both sides.Obviously to all on this board, it would be great to solve the problem with positive pressurization, but that is more often than not extremely costly. It is also virtually impossible in many buildings.What kinds of other methods do you fell may offer hope? I may be missing many. Thanks in advance, ~Cheryl

Looking for earth-friendly autos? Browse Top Cars by "Green Rating" at Yahoo! Autos' Green Center.

[Guest guest]

There is mold in every wall cavity in every house even brand new houses so long as they use wood studs or furring inside the walls. It is simply a matter of degree.

Rosen

Re: Ask Dr. Burge: Can We Use Heat to Remediate Mold Contamination?

,

I understand that one can never remove all mold from an environment. But I am not so certain it is wise to make a broad, general statement that it is acceptable to leave mold within wall cavities. I would venture to bet that if you posted your last message (see below) on the Sickbuildings website, you would get an earful back. Many on that board who are very ill, had a difficult time understanding what was causing their illness because there was no visible mold growth in their indoor environments. A good number of them are sick from mold that was hidden.

What to do with wall cavity mold, is an area that could really use further clarification and an understood industry standard of when to address and when not to.

Sharon

If a small amount of mold is hidden inside a wall and there is no moisture source and it is not detectable (spores or odor) in the living space, a good case would be to leave it where it is. Wall cavities are not living space. As someone that has inspected many, many homes under construction, there are not any new homes built that are mold free inside of wall cavities or inside of attics. And there are certainly no older homes that are mold free inside of walls and in the attic or other crawl spaces that are exposed to outside air.

You won't find any spec anywhere that says you have to remove mold inside wall cavities that is not detectable within the home.

Let's use some common sense here.

Rosen

The fish are biting.

Get more visitors on your site using Yahoo! Search Marketing.

[Guest guest]

Let me get to the point.. All molds are not the same. leaving some mold in walls is not a problem. The problems come when there has been a long term problem, caused by lack of maintenance, and then when people are called in to fix it, the same minimalist attitude is taken to fixing the problems that created them in the first place. That is how people end up getting really sick at their jobs or in their homes.. even after things should have been fixed.I have seen studies that have shown that humidity inside a wall cavity is directly correlated to toxinogenic mold species and their toxicity over time. (See one abstract from Indoor Air on the use of wall relative humidity to predict stachy in walls, below. High Wall RH can also reliably predict that a high amount of mycotoxins will be found - although low RH does not always mean the opposite.)

So, you can gather from that that truly toxic situations are unlikely to occur in a wall cavity when the humidity inside the wall cavity has not been high for an extended period of time - either at that time or in the not too distant past. As a longtime renter, I think its also extremely disturbing to me that a IAQ professional might end up being called in by a landlord to 'fix' a mold problem and might end up not even looking for it because it was inside of a wall cavity. Then they would sign off on the situation 'everything's okay' nudge nudge wink wink, and the tenant would be given an 'all clear' but would continue to get sicker and sicker. You know - of course, that this is common.-----Here is the paper I was giving as an example..Wall relative humidity: a simple and reliable index for predictingStachybotrys chartarum infestation in dwellings.

Indoor Air. 14(3):196-199, June 2004.Boutin-Forzano, S. 1; Charpin-Kadouch, C. 2; Chabbi, S. 2;Bennedjai, N. 3; Dumon, H. 4; Charpin, D. 1,2Abstract: Because the indoor mold Stachybotrys chartarum has been

considered as potentially responsible for serious health effects,its identification in dwellings with water damages is of utmostimportance. As such dwellings are many, it would be of great valueto have a simple and reliable index for predicting its presence. The

aim of the study was to compare measurements of wall relativehumidity (RH) to mold identification in 458 samples from 100dwellings. Mold identification was performed by direct microscopicexamination of a sample collected on the wall by the gummed paper

technique. Mean (+/- s.d.) wall RH (%) was much higher (97.0 +/-6.1) on the 30 samples where S. chartarum was identified comparedwith the 291 samples where other molds were identified (41.8 +/-36.9) and to the 137 samples where no molds were identified (

38.9+/- 34.8). There was no straightforward relationship between walland room RH. In conclusion, this study clearly demonstrate that thesimple measurement of wall RH can be used as a reliable index fordiscarding and suspecting S. chartarum infestation in dwellings.