[SPAM] Re: s 40-80 and 40-20

[Guest guest]

Jim,

You are the science guru. Please

help me with an issue when encapsulates are applied to exterior building

surfaces. The R-rating and the vapor transfer rating can be changed when

encapsulates are applied to either side of the outside wall cavity. Thus, potentially

causing a vapor-lock to occur in the exterior cavity that was not specked or

engineered for the life expectancy of the building.

I saw this condition further

exasperate a moisture condition in EIFS that surprisingly allowed mold to grow

behind the insulation.

Moffett

From:

iequality [mailto:iequality ] On Behalf Of Jim

H. White

Sent: Monday, June 11, 2007 4:54 PM

To: iequality

Subject: [sPAM] Re: s 40-80 and 40-20

Curtis

What

if all encapsulants had to be both transparent and free of toxins & toxic

solvents. then we could still see the materials that had been cleaned and also

avoid that nice buzz (due to brain cells incapacitated or killed).

Jim

H. White

System

Science Consulting

systemsa@...

-----

Original Message -----

From: Redington, Curtis

To: iequality

Sent: Monday, June 11,

2007 5:59 PM

Subject: RE:

s 40-80 and 40-20

,

Did I see you on " Dancing With The Stars " ?

That's some pretty fancy footwork! (I'm just jealous because I've got two

left feet!)

Seems like there must be consensus for a protocol to become a

" standard of care " . Otherwise, anyone could claim whatever they were

selling at the moment was a " standard of care " . Of course the

nature of consensus is such that not everyone agrees with everything, but at

least there is pretty much agreement on the major points. The

biggest disagreements involve the fuzzy little details. And, as the

folks who are really good know, it's the details that make the difference.

Hence the necessary reliance on " professional judgment " . So now it

just got even more complicated because in addition to trying to achieve

consensus on " how " , we also need some consensus on " who " .

That's why this List is so much fun - it's like the Abbot & Costello

" Who's On First " routine every day! Who is right? No, What is. What

is right? Yes! Could someone explain this to me? Surely - I don't

know. Don't call me Shirley. If you don't know, who does? Yes!

The standard of care for mold remediation is to return the indoor

environment to a " normal " condition. That involves a thorough job of

removing fungal contaminants and their associated microbiological neighbors.

But, since we live on a moldy, dirty planet, we don't have to achieve a sterile

condition. We do have to achieve moisture control, though. Do we have consensus

so far? OK, but what is " normal " and how do we define what is a

" thorough job " ? Depends on who you are talking to and what is motivating

them.

Here are some reasons why I don't think encapsulation would be

described as a " standard of care " . First, there are all the

contractors who think that if they spray everything white, then you don't have

any more " black mold " (because now it's all white, and everyone

knows that you only have to worry about " black " mold!). Second,

the consultant is trying to determine if the area is free of any visible

dust/debris/mold, but now everything is white and fuzzy from overspray. In

addition, any moldy odors that could be a clue are masked by the odor of the

encapsulant. Nice buzz if you get if fresh enough, but not exactly helpful when

you're trying to document clearance. Third, mold sprayed with encapsulant can

still grow if the water problem wasn't fixed. It just has to work at it a

little harder. Fourth, mold grows (at least the viable parts), asbestos

doesn't. Nor does fiberglass, lead paint, mercury, or other non-living stuff

(i.e., organisms - both with and without lungs).

So, I'm saying that we shouldn't routinely paint everything as part

of a mold remediation (just like we shouldn't routinely use bleach and water).

But, there certainly can be circumstances where encapsulation would be useful

as part of some mold remediation plans. In these situations, the encapsulant

need only be applied to the specific areas where sealing or " locking

down " of the surface is necessary (because it can't otherwise be

remediated). A classic example could be applying a sealant/encapsulant at the

joint between sole plate and sub floor. This would also help to keep moisture

out, should another water problem develop.

So, who's on first?

Curtis

Re: s 40-80 and 40-20

EnviroBob:

I respectfully disagree, and I believe you are providing Shell with some

poor advice!

Post-remediation encapsulation is a standard of care within the

remediation industry, and there is a lot of value to encapsulation.

The foundation of your opinion seems to be focused on the premise

that encapsulation is used on poor quality remediation efforts in order to

hide a source contaminant. Not true. The purpose of

encapsulation is to lock down any remaining contaminant that has avoided

being removed, and seal surfaces so new products can be applied and/or

the (remediated) space being re-occupied without fear of exposure to workers

rehabilitating the work area. If you can claim that all bio-mass

has been removed, then you could claim that the space was essentially

sterile – not possible! Encapsulants are a standard of care

for many types of remediation and construction efforts, e.g., asbestos,

LBP, mercury, silica, fiberglass, partial demo, and mold. Moreo

ver, encapsulated surfaces resist new biological infestations, moisture

imbibition is slowed, and they are easier to re-clean if soiled. To

not use encapsulants post-remediation may be a negligent act; depending

upon the circumstance.

While I agree that pigmented encapsulants can be used to hide poor

quality remediation work, this is not their purpose. Similarly,

drywall mud and paint can hide problems with wall assemblies on the

inside, and stucco can effectively hide them on the outside; but this is

not the purpose of the coating material.

In your previous posts, you have positioned yourself as a “total

source removal” advocate; however, you have failed to acknowledge

the practical aspects that do not always support this position, e.g.,

budgetary limitations, loss of use restrictions, and/or accessing

inaccessible interstitial spaces. (I recall that you were the

person that advocated disassembling a wood-framed wall system in order to

scrub each piece of wood until it was free of mold, then re-building.)

On most mold-related projects, it is practical to remove and/or

clean what is readily accessible – acknowledging that some bio-mass

will remain behind, mitigate the source of moisture, encapsulate exposed

building materials after a PRV visual and sampling regime, encapsulate,

then build-back. This is consistent with many other standards of

care where contaminant reduction/mitigation is warranted .

How is it that you can state: “Additionally, if the framing is encapsulated

after the remediation process then the loss has not been restored back to

the pre-loss condition.”? Huh? This is an unfounded

opinion and does not have merit. Moreover, I and A LOT of

contractors I know of take exception to your comment: “Normally

that procedure is done when the remediation contractor feels they have

not done adequate cleaning.” What BS! Based on your

comments, I really don’t believe you know what “normal” is.

Maybe you should align yourself with some good-quality remediation

contractors who are not trying to hide anything, strive to do good work,

and provide a clean post-remediation work space. We encapsulate

these workspaces after everyone is satisfied with the cleanliness.

Encapsulation is often a very minor cost o f the total project

effort, it is quick, and its value is well-understood by all involved....except

you, it appears.

If you can have cleaned to a press-loss condition, all sources of

bio-mass and do so with the confidence that you can leave that space fit

for re-occupancy without using a method (i.e., encapsulation) whose value

has been well-demonstrated for nearly 20-years....more power to you.

IMHO, you are also denying the building owners the value that

encapsulants provide, and you are not conducting your work within an

accepted industry practice.

For what it is worth.....

On 6/1/07 4:19 AM, " EnviroBob "

wrote:

[Guest guest]

Jim,

You are the science guru. Please

help me with an issue when encapsulates are applied to exterior building

surfaces. The R-rating and the vapor transfer rating can be changed when

encapsulates are applied to either side of the outside wall cavity. Thus, potentially

causing a vapor-lock to occur in the exterior cavity that was not specked or

engineered for the life expectancy of the building.

I saw this condition further

exasperate a moisture condition in EIFS that surprisingly allowed mold to grow

behind the insulation.

Moffett

From:

iequality [mailto:iequality ] On Behalf Of Jim

H. White

Sent: Monday, June 11, 2007 4:54 PM

To: iequality

Subject: [sPAM] Re: s 40-80 and 40-20

Curtis

What

if all encapsulants had to be both transparent and free of toxins & toxic

solvents. then we could still see the materials that had been cleaned and also

avoid that nice buzz (due to brain cells incapacitated or killed).

Jim

H. White

System

Science Consulting

systemsa@...

-----

Original Message -----

From: Redington, Curtis

To: iequality

Sent: Monday, June 11,

2007 5:59 PM

Subject: RE:

s 40-80 and 40-20

,

Did I see you on " Dancing With The Stars " ?

That's some pretty fancy footwork! (I'm just jealous because I've got two

left feet!)

Seems like there must be consensus for a protocol to become a

" standard of care " . Otherwise, anyone could claim whatever they were

selling at the moment was a " standard of care " . Of course the

nature of consensus is such that not everyone agrees with everything, but at

least there is pretty much agreement on the major points. The

biggest disagreements involve the fuzzy little details. And, as the

folks who are really good know, it's the details that make the difference.

Hence the necessary reliance on " professional judgment " . So now it

just got even more complicated because in addition to trying to achieve

consensus on " how " , we also need some consensus on " who " .

That's why this List is so much fun - it's like the Abbot & Costello

" Who's On First " routine every day! Who is right? No, What is. What

is right? Yes! Could someone explain this to me? Surely - I don't

know. Don't call me Shirley. If you don't know, who does? Yes!

The standard of care for mold remediation is to return the indoor

environment to a " normal " condition. That involves a thorough job of

removing fungal contaminants and their associated microbiological neighbors.

But, since we live on a moldy, dirty planet, we don't have to achieve a sterile

condition. We do have to achieve moisture control, though. Do we have consensus

so far? OK, but what is " normal " and how do we define what is a

" thorough job " ? Depends on who you are talking to and what is motivating

them.

Here are some reasons why I don't think encapsulation would be

described as a " standard of care " . First, there are all the

contractors who think that if they spray everything white, then you don't have

any more " black mold " (because now it's all white, and everyone

knows that you only have to worry about " black " mold!). Second,

the consultant is trying to determine if the area is free of any visible

dust/debris/mold, but now everything is white and fuzzy from overspray. In

addition, any moldy odors that could be a clue are masked by the odor of the

encapsulant. Nice buzz if you get if fresh enough, but not exactly helpful when

you're trying to document clearance. Third, mold sprayed with encapsulant can

still grow if the water problem wasn't fixed. It just has to work at it a

little harder. Fourth, mold grows (at least the viable parts), asbestos

doesn't. Nor does fiberglass, lead paint, mercury, or other non-living stuff

(i.e., organisms - both with and without lungs).

So, I'm saying that we shouldn't routinely paint everything as part

of a mold remediation (just like we shouldn't routinely use bleach and water).

But, there certainly can be circumstances where encapsulation would be useful

as part of some mold remediation plans. In these situations, the encapsulant

need only be applied to the specific areas where sealing or " locking

down " of the surface is necessary (because it can't otherwise be

remediated). A classic example could be applying a sealant/encapsulant at the

joint between sole plate and sub floor. This would also help to keep moisture

out, should another water problem develop.

So, who's on first?

Curtis

Re: s 40-80 and 40-20

EnviroBob:

I respectfully disagree, and I believe you are providing Shell with some

poor advice!

Post-remediation encapsulation is a standard of care within the

remediation industry, and there is a lot of value to encapsulation.

The foundation of your opinion seems to be focused on the premise

that encapsulation is used on poor quality remediation efforts in order to

hide a source contaminant. Not true. The purpose of

encapsulation is to lock down any remaining contaminant that has avoided

being removed, and seal surfaces so new products can be applied and/or

the (remediated) space being re-occupied without fear of exposure to workers

rehabilitating the work area. If you can claim that all bio-mass

has been removed, then you could claim that the space was essentially

sterile – not possible! Encapsulants are a standard of care

for many types of remediation and construction efforts, e.g., asbestos,

LBP, mercury, silica, fiberglass, partial demo, and mold. Moreo

ver, encapsulated surfaces resist new biological infestations, moisture

imbibition is slowed, and they are easier to re-clean if soiled. To

not use encapsulants post-remediation may be a negligent act; depending

upon the circumstance.

While I agree that pigmented encapsulants can be used to hide poor

quality remediation work, this is not their purpose. Similarly,

drywall mud and paint can hide problems with wall assemblies on the

inside, and stucco can effectively hide them on the outside; but this is

not the purpose of the coating material.

In your previous posts, you have positioned yourself as a “total

source removal” advocate; however, you have failed to acknowledge

the practical aspects that do not always support this position, e.g.,

budgetary limitations, loss of use restrictions, and/or accessing

inaccessible interstitial spaces. (I recall that you were the

person that advocated disassembling a wood-framed wall system in order to

scrub each piece of wood until it was free of mold, then re-building.)

On most mold-related projects, it is practical to remove and/or

clean what is readily accessible – acknowledging that some bio-mass

will remain behind, mitigate the source of moisture, encapsulate exposed

building materials after a PRV visual and sampling regime, encapsulate,

then build-back. This is consistent with many other standards of

care where contaminant reduction/mitigation is warranted .

How is it that you can state: “Additionally, if the framing is encapsulated

after the remediation process then the loss has not been restored back to

the pre-loss condition.”? Huh? This is an unfounded

opinion and does not have merit. Moreover, I and A LOT of

contractors I know of take exception to your comment: “Normally

that procedure is done when the remediation contractor feels they have

not done adequate cleaning.” What BS! Based on your

comments, I really don’t believe you know what “normal” is.

Maybe you should align yourself with some good-quality remediation

contractors who are not trying to hide anything, strive to do good work,

and provide a clean post-remediation work space. We encapsulate

these workspaces after everyone is satisfied with the cleanliness.

Encapsulation is often a very minor cost o f the total project

effort, it is quick, and its value is well-understood by all involved....except

you, it appears.

If you can have cleaned to a press-loss condition, all sources of

bio-mass and do so with the confidence that you can leave that space fit

for re-occupancy without using a method (i.e., encapsulation) whose value

has been well-demonstrated for nearly 20-years....more power to you.

IMHO, you are also denying the building owners the value that

encapsulants provide, and you are not conducting your work within an

accepted industry practice.

For what it is worth.....

On 6/1/07 4:19 AM, " EnviroBob "

wrote:

[Guest guest]

Most moisture travels by liquid processes, then by transport in flowing air and then by diffusion. If the first two are not right, don't worry about the third. That said, especially in areas where the air outdoors is hot and muggy, or where someone is trying to keep a tropical climate indoors when the building was not designed for those conditions, diffusion of water right through non-porous materials can be a problem; over time.

Any vapour retarder on or near an outdoor surface is a bad idea in a cold climate. Any vapour retarder near an indoor surface is a bad idea on or near an indoor surface when it is often hot and very humid outdoors. When you do the numbers you can quickly see why plastic films near the outdoor surfaces in cold climates and vinyl wallpaper on indoor surfaces in hot and humid climates are a very bad idea.

Interestingly enough, almost every EIFS problem had more to do with a leak of water (wind-driven rain) than diffusion; the system could not allow much diffusion of the subsequently soaked materials so the system fails. EIFS relies on perfect installation and perfect maintenance in what I believe is a world populated by ordinary, fallible people. This is a recipe for long-term disaster because even an almost perfect installation can go down the tubes when the caulking is not kept up to par, even through one critical storm that occurs between an identified caulking failure and the planned remedial measure. Never try to stop water movement on a water planet!

Jim H. White SSC

Re: s 40-80 and 40-20EnviroBob:I respectfully disagree, and I believe you are providing Shell with some poor advice!Post-remediation encapsulation is a standard of care within the remediation industry, and there is a lot of value to encapsulation. The foundation of your opinion seems to be focused on the premise that encapsulation is used on poor quality remediation efforts in order to hide a source contaminant. Not true. The purpose of encapsulation is to lock down any remaining contaminant that has avoided being removed, and seal surfaces so new products can be applied and/or the (remediated) space being re-occupied without fear of exposure to workers rehabilitating the work area. If you can claim that all bio-mass has been removed, then you could claim that the space was essentially sterile – not possible! Encapsulants are a standard of care for many types of remediation and construction efforts, e.g., asbestos, LBP, mercury, silica, fiberglass, partial demo, and mold. Moreo ver, encapsulated surfaces resist new biological infestations, moisture imbibition is slowed, and they are easier to re-clean if soiled. To not use encapsulants post-remediation may be a negligent act; depending upon the circumstance.While I agree that pigmented encapsulants can be used to hide poor quality remediation work, this is not their purpose. Similarly, drywall mud and paint can hide problems with wall assemblies on the inside, and stucco can effectively hide them on the outside; but this is not the purpose of the coating material.In your previous posts, you have positioned yourself as a “total source removal” advocate; however, you have failed to acknowledge the practical aspects that do not always support this position, e.g., budgetary limitations, loss of use restrictions, and/or accessing inaccessible interstitial spaces. (I recall that you were the person that advocated disassembling a wood-framed wall system in order to scrub each piece of wood until it was free of mold, then re-building.) On most mold-related projects, it is practical to remove and/or clean what is readily accessible – acknowledging that some bio-mass will remain behind, mitigate the source of moisture, encapsulate exposed building materials after a PRV visual and sampling regime, encapsulate, then build-back. This is consistent with many other standards of care where contaminant reduction/mitigation is warranted .How is it that you can state: “Additionally, if the framing is encapsulated after the remediation process then the loss has not been restored back to the pre-loss condition.”? Huh? This is an unfounded opinion and does not have merit. Moreover, I and A LOT of contractors I know of take exception to your comment: “Normally that procedure is done when the remediation contractor feels they have not done adequate cleaning.” What BS! Based on your comments, I really don’t believe you know what “normal” is. Maybe you should align yourself with some good-quality remediation contractors who are not trying to hide anything, strive to do good work, and provide a clean post-remediation work space. We encapsulate these workspaces after everyone is satisfied with the cleanliness. Encapsulation is often a very minor cost o f the total project effort, it is quick, and its value is well-understood by all involved....except you, it appears.If you can have cleaned to a press-loss condition, all sources of bio-mass and do so with the confidence that you can leave that space fit for re-occupancy without using a method (i.e., encapsulation) whose value has been well-demonstrated for nearly 20-years....more power to you. IMHO, you are also denying the building owners the value that encapsulants provide, and you are not conducting your work within an accepted industry practice.For what it is worth.....On 6/1/07 4:19 AM, "EnviroBob" <BobEnvironmentalAirTechs> wrote:

[Guest guest]

Most moisture travels by liquid processes, then by transport in flowing air and then by diffusion. If the first two are not right, don't worry about the third. That said, especially in areas where the air outdoors is hot and muggy, or where someone is trying to keep a tropical climate indoors when the building was not designed for those conditions, diffusion of water right through non-porous materials can be a problem; over time.

Any vapour retarder on or near an outdoor surface is a bad idea in a cold climate. Any vapour retarder near an indoor surface is a bad idea on or near an indoor surface when it is often hot and very humid outdoors. When you do the numbers you can quickly see why plastic films near the outdoor surfaces in cold climates and vinyl wallpaper on indoor surfaces in hot and humid climates are a very bad idea.

Interestingly enough, almost every EIFS problem had more to do with a leak of water (wind-driven rain) than diffusion; the system could not allow much diffusion of the subsequently soaked materials so the system fails. EIFS relies on perfect installation and perfect maintenance in what I believe is a world populated by ordinary, fallible people. This is a recipe for long-term disaster because even an almost perfect installation can go down the tubes when the caulking is not kept up to par, even through one critical storm that occurs between an identified caulking failure and the planned remedial measure. Never try to stop water movement on a water planet!

Jim H. White SSC

Re: s 40-80 and 40-20EnviroBob:I respectfully disagree, and I believe you are providing Shell with some poor advice!Post-remediation encapsulation is a standard of care within the remediation industry, and there is a lot of value to encapsulation. The foundation of your opinion seems to be focused on the premise that encapsulation is used on poor quality remediation efforts in order to hide a source contaminant. Not true. The purpose of encapsulation is to lock down any remaining contaminant that has avoided being removed, and seal surfaces so new products can be applied and/or the (remediated) space being re-occupied without fear of exposure to workers rehabilitating the work area. If you can claim that all bio-mass has been removed, then you could claim that the space was essentially sterile – not possible! Encapsulants are a standard of care for many types of remediation and construction efforts, e.g., asbestos, LBP, mercury, silica, fiberglass, partial demo, and mold. Moreo ver, encapsulated surfaces resist new biological infestations, moisture imbibition is slowed, and they are easier to re-clean if soiled. To not use encapsulants post-remediation may be a negligent act; depending upon the circumstance.While I agree that pigmented encapsulants can be used to hide poor quality remediation work, this is not their purpose. Similarly, drywall mud and paint can hide problems with wall assemblies on the inside, and stucco can effectively hide them on the outside; but this is not the purpose of the coating material.In your previous posts, you have positioned yourself as a “total source removal” advocate; however, you have failed to acknowledge the practical aspects that do not always support this position, e.g., budgetary limitations, loss of use restrictions, and/or accessing inaccessible interstitial spaces. (I recall that you were the person that advocated disassembling a wood-framed wall system in order to scrub each piece of wood until it was free of mold, then re-building.) On most mold-related projects, it is practical to remove and/or clean what is readily accessible – acknowledging that some bio-mass will remain behind, mitigate the source of moisture, encapsulate exposed building materials after a PRV visual and sampling regime, encapsulate, then build-back. This is consistent with many other standards of care where contaminant reduction/mitigation is warranted .How is it that you can state: “Additionally, if the framing is encapsulated after the remediation process then the loss has not been restored back to the pre-loss condition.”? Huh? This is an unfounded opinion and does not have merit. Moreover, I and A LOT of contractors I know of take exception to your comment: “Normally that procedure is done when the remediation contractor feels they have not done adequate cleaning.” What BS! Based on your comments, I really don’t believe you know what “normal” is. Maybe you should align yourself with some good-quality remediation contractors who are not trying to hide anything, strive to do good work, and provide a clean post-remediation work space. We encapsulate these workspaces after everyone is satisfied with the cleanliness. Encapsulation is often a very minor cost o f the total project effort, it is quick, and its value is well-understood by all involved....except you, it appears.If you can have cleaned to a press-loss condition, all sources of bio-mass and do so with the confidence that you can leave that space fit for re-occupancy without using a method (i.e., encapsulation) whose value has been well-demonstrated for nearly 20-years....more power to you. IMHO, you are also denying the building owners the value that encapsulants provide, and you are not conducting your work within an accepted industry practice.For what it is worth.....On 6/1/07 4:19 AM, "EnviroBob" <BobEnvironmentalAirTechs> wrote:

[Guest guest]

Wane,

Good work! Excellent points!

There are several mold-resistant coatings/sealants and/or EPA-

registered fungicidal coatings (terms I prefer to " encapsulant " -

misleading when mold is involved - but that is for another thread)

which demonstrate permeability such that on a wood substrate with a

moisture content of 15% or less, the moisture will be able to migrate

out sufficiently to avoid detrimental effects to the substrate, and

the coating should not lose adhesion.

(I apologize to the group if any of this has already been covered as

I read Wane's post only, and decided to jump into the pool too)

Wane, the only quibbling I would have with your post is not with you,

but with the manufacturer's technical data sheet for this product.

When tested using ASTM F 1249, the result was a performance of 6

perms. However, according to Tom Sliva at Litter Laboratories

in New York (one of the best resources around when it comes to

questions of coatings of any type, performance standards, lab

procedures, coatings forensics, etc), ASTM F 1249 is a standard

applied to the permeability of commercial plastic packaging

materials. You can read the abstract on ASTM's website at:

http://www.astm.org/cgi-

bin/SoftCart.exe/DATABASE.CART/REDLINE_PAGES/F1249.htm?

L+mystore+qnle5559 , or just put F1249 in the search box on the ASTM

home page if this link doesn't come through formatted right.

ASTM 1249 was proposed as a protocol to the coatings committee at

ASTM years ago, and it was rejected as unsuitable. At some point

later on, it was adopted by the ASTM Food & Consumer Packaging

Committee, and thus the F designation, according to Mr. Sliva.

More applicable ASTM methods which have been adopted to measure the

permeability of coatings in general include E 96 and D 1653, the

latter of which is most commonly used (Method A, Condition A, Dry Cup

typically of the variants available). When Litter Labs was

asked to test 40-20 to this method (we sponsored the testing, DL-

Report No. 13782, March 13, 2003), the result came back as 1.2

perms. This is, of course, substantially lower than 6 perms, and

while I cannot correlate any relation between the F 1249 data and the

D 1653 results, this is relatively low permeability for a coating.

Other coatings and sealants produced for mold remediation/prevention

demonstrate significantly higher permeability, and some manufacturers

can produce performance data from independent and certfied

laboratories to this effect (although not enough manufacturers invest

money in performance testing unless required to do so - something

which is not yet the case with mold-related coatings). Anyone who

wants a copy of the aforementioned DL report, just send me an email

and I can send you back a PDF.

At the end of the day, the subject of permeability makes me remember

the discussions we had on the ASTM Lead Encapsulants committee on

this subject. Should there be a threshold of minimum permeability

that a coating would have to achieve to be a lead encapsulant. The

committee decided that there would not be, but that a candidate

product would have to be tested to D 1653. Why? Because it is

important for a consultant, building engineer, etc., to have that

data from an independent and certified lab when evaluating whether a

particular encapsulant is appropriate for a particular situation. In

other words, in some cases lower permeability may not be mission

critical, whereas for other projects the circumstances might dictate

that one find a product with the greatest possible permeability,

or...not use a coating there at all. With E 1795 for lead

encapsulants, we decided that the data itself was valuable and should

come from an unimpeachable source, and then a consulting professional

had a least some information to work with.

Hopefully the practice of testing for permeability at an accredited

and reputable lab will spread among the manufacturers of the coatings

and sealants currently produced for mold-related applications. In

the meantime, it is advisable to all to ask any manufacturer for a

copy of the actual test report itself from the testing lab. If that

report is not forthcoming - caveat emptor.

Cole Stanton

FIBERLOCK

cwds@...

> >

> > ,

> >

> > Good points to bring up. Since we are being specific to 's

> 40-20, when

> > a contractor appropriately applies 40-20, the mil-thickness after

> drying and

> > curing is greater than 6-mils. Meaning, it is put on at 10-mils

and

> dries to

> > 6-mil thickness (+/- a percent or two depending on the surface,

> absorbency,

> > temperature, RH, etc.)

> >

> > 's 40-20, properly applied I believe exceeds a PERM-rating

of

> more

> > than 1.

> >

> > Moffett

> >

> >

> >

> > From: iequality

[mailto:iequality ] On

> Behalf

> > Of Geyer

> > Sent: Tuesday, June 12, 2007 9:42 AM

> > To: iequality

> > Subject: Re: [sPAM] Re: s 40-80 and 40-20

> >

> >

> >

> > Pat:

> >

> > Let's not be too hastly to blame all encapsulants for vapor-

lockup.

> Some

> > encapsulants have a PERM rating greater than 1.0, therefore, they

> would be

> > classified as a vapor retarder (like Dupont's TYVEK House Wrap)

and

> not a

> > vapor barrier (like 4mil poly sheeting). However, your point is

well

> taken,

> > and it is an issue to be reckoned with for all coatings, not just

> > encapsulants, i.e., are they compatible with the building

> assembly/system to

> > which they are applied? This is where the mustard meets the road

> regarding

> > folks that know building systems versus those that don't, i.e.,

> material's

> > science.

> >

> > For what it is worth....

> >

> >

>

[Guest guest]

Wayne:

FYI, there are some silica and siloxane-based coatings that are used primarily in the ceramics industry, that are used for their non-penetrating, bridging encapsulant-like properties, and these products have PERM ratings of 45 to 50. I have used these products on CMU wall systems after abating LBP where we needed a high PERM thin-film surface encapsulant that had high solids content and was compatible to the facility’s use. They worked well and performed as anticipated.

While I agree that most folks in the environmental industry have a rather myopic approach to what constitutes an encapsulant, the breadth of encapsulant-like products that are available is very broad. Yes, most IEPs think of, specify, and use a narrow list of encapsulants that typically have PERM ratings lass than 10, and some encapsulants can classify as a vapor barrier with a PERM rating than 1. It doe not have to be so limited, and it really depends; sometimes a low PERM encapsulant is warranted. I have applied coatings that have been nominal-DFT 140-mil thick and I know for a fact that the PERM rating is much less than 1.

I would like to add that s 40-20 is but one product available to us IEPs. I see it used often, and I rarely see it applied to a dry nominal thickness of 11-mils – per s spec. Usually, I see it applied 2 to 3-mils thick, and sometimes it is 4 to 5-mils. (I collect coupons and mic the film and/or use a penetrometer to measure the thickness of the coating.) So....if the manufacture specifies 11-mil nominal DFT (dry film thickness), and it’s in-the-field average thickness is much less.....what is the PERM as-applied? Probably much less than 6. Moreover, if the thickness is not what the manufacturer specifies, is it TOTALLY ineffective? Is it TOTALLY ineffective as an encapsulant? I say no, because it depends. I also know for a fact that manufacturers often specify thick coatings, not because their product is less effective with thinner coatings, but because more product is used thereby sales are increased. Therefore, it really depends on the intended use and function of the product, i.e., the encapsulant. I tend to prefer high-solid, low VOC, thin-film encapsulants; which tend to have very little effect on system permeability. I do not like applying coatings that are vapor barriers when I do not want a vapor barrier; I want an encapsulant. Therefore, I often specify thinner than mfg spec coatings, e.g., s 40-20.

As I mentioned before, I like diluted Elmers white glue as a cheap encapsulant to lock down potential aerosols and surface coat areas where abatement/demolition has been performed. Elmers glue is basically polyvinyl acetate, water soluble, low-VOC, relatively non-toxic and CHEAP. It is also quite effective as a thin-film encapsulant and very permeable when applied as a thin-film encapsulant; what the PERM rating is I have no idea, I could only guess. Surprisingly, it is also very compatible with many materials we find in the build environment, with the most notable exception of fire-proofing. And it is CHEAP....but I said that already.

Bottom line....I have done my homework and continue to do so, because there is so much to learn.

For what it is worth....

please do your homework.

no coating/paint/encapsulant is " like Tyvek " -- not even close!

40-20 (per mfr technical data sheet)

wet film thickness: 20 mils; dry film thickness: 11 mils; permeance: 6 perms at 11 mils DFT

Tyvek: (Spun bonded polyolefin, 0.006 in., 0.013 lb/ft2)

~70 perms (per the mfr, slightly less than 70; per ASHRAE ~76 perms)

other building materials of interest:

1/2 inch gysum wallboard: 55 perms at 50% RH

one inch of still air: 120 perms (the reference point)

6 mil poly sheeting: 0.06 perm

typical latex paints at 1-2 mils DFT: 5-8 perms

1/2 inch OSB: ~0.6 perms at 50% RH

1/2 inch plywood: 1 perm at 50% RH

those quoted " at 50% " demonstrate variable permeability based on installed conditions.

for more see: 2005 ASHRAE Handbook of Fundamentals, Chapter 25

also see: ASHRAE Research Project RP-1018, " A Thermal and Moisture Transport Property Database for Common Building and Insulating Materials " , July 2002

Wane

<><><><><><><><><><><>

Wane A. Baker, P.E., CIH

Division Manager, Indoor Air Quality

MICHAELS ENGINEERING

" Real Professionals. Real Solutions. "

St. , La Crosse, Milwaukee

Phone , ext. 484

Cell

Fax

mailto:wab@...

On the web at: http://www.michaelsengineering.com <http://www.michaelsengineering.com/>

" To love what you do and feel that it matters - how could anything be more fun? "

- Graham

>

> ,

>

> Good points to bring up. Since we are being specific to 's 40-20, when

> a contractor appropriately applies 40-20, the mil-thickness after drying and

> curing is greater than 6-mils. Meaning, it is put on at 10-mils and dries to

> 6-mil thickness (+/- a percent or two depending on the surface, absorbency,

> temperature, RH, etc.)

>

> 's 40-20, properly applied I believe exceeds a PERM-rating of more

> than 1.

>

> Moffett

>

>

>

> From: iequality [mailto:iequality ] On Behalf

> Of Geyer

> Sent: Tuesday, June 12, 2007 9:42 AM

> To: iequality

> Subject: Re: [sPAM] Re: s 40-80 and 40-20

>

>

>

> Pat:

>

> Let's not be too hastly to blame all encapsulants for vapor-lockup. Some

> encapsulants have a PERM rating greater than 1.0, therefore, they would be

> classified as a vapor retarder (like Dupont's TYVEK House Wrap) and not a

> vapor barrier (like 4mil poly sheeting). However, your point is well taken,

> and it is an issue to be reckoned with for all coatings, not just

> encapsulants, i.e., are they compatible with the building assembly/system to

> which they are applied? This is where the mustard meets the road regarding

> folks that know building systems versus those that don't, i.e., material's

> science.

>

> For what it is worth....

>

>

[Guest guest]

Wayne:

FYI, there are some silica and siloxane-based coatings that are used primarily in the ceramics industry, that are used for their non-penetrating, bridging encapsulant-like properties, and these products have PERM ratings of 45 to 50. I have used these products on CMU wall systems after abating LBP where we needed a high PERM thin-film surface encapsulant that had high solids content and was compatible to the facility’s use. They worked well and performed as anticipated.

While I agree that most folks in the environmental industry have a rather myopic approach to what constitutes an encapsulant, the breadth of encapsulant-like products that are available is very broad. Yes, most IEPs think of, specify, and use a narrow list of encapsulants that typically have PERM ratings lass than 10, and some encapsulants can classify as a vapor barrier with a PERM rating than 1. It doe not have to be so limited, and it really depends; sometimes a low PERM encapsulant is warranted. I have applied coatings that have been nominal-DFT 140-mil thick and I know for a fact that the PERM rating is much less than 1.

I would like to add that s 40-20 is but one product available to us IEPs. I see it used often, and I rarely see it applied to a dry nominal thickness of 11-mils – per s spec. Usually, I see it applied 2 to 3-mils thick, and sometimes it is 4 to 5-mils. (I collect coupons and mic the film and/or use a penetrometer to measure the thickness of the coating.) So....if the manufacture specifies 11-mil nominal DFT (dry film thickness), and it’s in-the-field average thickness is much less.....what is the PERM as-applied? Probably much less than 6. Moreover, if the thickness is not what the manufacturer specifies, is it TOTALLY ineffective? Is it TOTALLY ineffective as an encapsulant? I say no, because it depends. I also know for a fact that manufacturers often specify thick coatings, not because their product is less effective with thinner coatings, but because more product is used thereby sales are increased. Therefore, it really depends on the intended use and function of the product, i.e., the encapsulant. I tend to prefer high-solid, low VOC, thin-film encapsulants; which tend to have very little effect on system permeability. I do not like applying coatings that are vapor barriers when I do not want a vapor barrier; I want an encapsulant. Therefore, I often specify thinner than mfg spec coatings, e.g., s 40-20.

As I mentioned before, I like diluted Elmers white glue as a cheap encapsulant to lock down potential aerosols and surface coat areas where abatement/demolition has been performed. Elmers glue is basically polyvinyl acetate, water soluble, low-VOC, relatively non-toxic and CHEAP. It is also quite effective as a thin-film encapsulant and very permeable when applied as a thin-film encapsulant; what the PERM rating is I have no idea, I could only guess. Surprisingly, it is also very compatible with many materials we find in the build environment, with the most notable exception of fire-proofing. And it is CHEAP....but I said that already.

Bottom line....I have done my homework and continue to do so, because there is so much to learn.

For what it is worth....

please do your homework.

no coating/paint/encapsulant is " like Tyvek " -- not even close!

40-20 (per mfr technical data sheet)

wet film thickness: 20 mils; dry film thickness: 11 mils; permeance: 6 perms at 11 mils DFT

Tyvek: (Spun bonded polyolefin, 0.006 in., 0.013 lb/ft2)

~70 perms (per the mfr, slightly less than 70; per ASHRAE ~76 perms)

other building materials of interest:

1/2 inch gysum wallboard: 55 perms at 50% RH

one inch of still air: 120 perms (the reference point)

6 mil poly sheeting: 0.06 perm

typical latex paints at 1-2 mils DFT: 5-8 perms

1/2 inch OSB: ~0.6 perms at 50% RH

1/2 inch plywood: 1 perm at 50% RH

those quoted " at 50% " demonstrate variable permeability based on installed conditions.

for more see: 2005 ASHRAE Handbook of Fundamentals, Chapter 25

also see: ASHRAE Research Project RP-1018, " A Thermal and Moisture Transport Property Database for Common Building and Insulating Materials " , July 2002

Wane

<><><><><><><><><><><>

Wane A. Baker, P.E., CIH

Division Manager, Indoor Air Quality

MICHAELS ENGINEERING

" Real Professionals. Real Solutions. "

St. , La Crosse, Milwaukee

Phone , ext. 484

Cell

Fax

mailto:wab@...

On the web at: http://www.michaelsengineering.com <http://www.michaelsengineering.com/>

" To love what you do and feel that it matters - how could anything be more fun? "

- Graham

>

> ,

>

> Good points to bring up. Since we are being specific to 's 40-20, when

> a contractor appropriately applies 40-20, the mil-thickness after drying and

> curing is greater than 6-mils. Meaning, it is put on at 10-mils and dries to

> 6-mil thickness (+/- a percent or two depending on the surface, absorbency,

> temperature, RH, etc.)

>

> 's 40-20, properly applied I believe exceeds a PERM-rating of more

> than 1.

>

> Moffett

>

>

>

> From: iequality [mailto:iequality ] On Behalf

> Of Geyer

> Sent: Tuesday, June 12, 2007 9:42 AM

> To: iequality

> Subject: Re: [sPAM] Re: s 40-80 and 40-20

>

>

>

> Pat:

>

> Let's not be too hastly to blame all encapsulants for vapor-lockup. Some

> encapsulants have a PERM rating greater than 1.0, therefore, they would be

> classified as a vapor retarder (like Dupont's TYVEK House Wrap) and not a

> vapor barrier (like 4mil poly sheeting). However, your point is well taken,

> and it is an issue to be reckoned with for all coatings, not just

> encapsulants, i.e., are they compatible with the building assembly/system to

> which they are applied? This is where the mustard meets the road regarding

> folks that know building systems versus those that don't, i.e., material's

> science.

>

> For what it is worth....

>

>

[Guest guest]

Hello ,

I have been on vacation, but wanted to check to see if you responded to my question about how well the wood building materials needed to be cleaned prior to coating? I did not see a serious answer in screening the emails. Are you even testing prior to coating? Please don't dance around the question. We rec coating when it is needed, but only after cleaning as best practical and surface testing.

Question about the under side of the wood flooring systems in crawl spaces -- is there a real concern about a thick anti microbial coating on the OSB or plywood, say a PERM of 2 to 6?

PS -- What is your procedure for making sure the building owner maintains the coating?

Bradley HarrSr. Environmental Scientist

Re: [sPAM] Re: s 40-80 and 40-20> > > > Pat:> > Let's not be too hastly to blame all encapsulants for vapor-lockup. Some> encapsulants have a PERM rating greater than 1.0, therefore, they would be> classified as a vapor retarder (like Dupont's TYVEK House Wrap) and not a> vapor barrier (like 4mil poly sheeting). However, your point is well taken,> and it is an issue to be reckoned with for all coatings, not just> encapsulants, i.e., are they compatible with the building assembly/system to> which they are applied? This is where the mustard meets the road regarding> folks that know building systems versus those that don't, i.e., material's> science.> > For what it is worth....> >

[Guest guest]

Hello ,

I have been on vacation, but wanted to check to see if you responded to my question about how well the wood building materials needed to be cleaned prior to coating? I did not see a serious answer in screening the emails. Are you even testing prior to coating? Please don't dance around the question. We rec coating when it is needed, but only after cleaning as best practical and surface testing.

Question about the under side of the wood flooring systems in crawl spaces -- is there a real concern about a thick anti microbial coating on the OSB or plywood, say a PERM of 2 to 6?

PS -- What is your procedure for making sure the building owner maintains the coating?

Bradley HarrSr. Environmental Scientist

Re: [sPAM] Re: s 40-80 and 40-20> > > > Pat:> > Let's not be too hastly to blame all encapsulants for vapor-lockup. Some> encapsulants have a PERM rating greater than 1.0, therefore, they would be> classified as a vapor retarder (like Dupont's TYVEK House Wrap) and not a> vapor barrier (like 4mil poly sheeting). However, your point is well taken,> and it is an issue to be reckoned with for all coatings, not just> encapsulants, i.e., are they compatible with the building assembly/system to> which they are applied? This is where the mustard meets the road regarding> folks that know building systems versus those that don't, i.e., material's> science.> > For what it is worth....> >

[Guest guest]

Brad:

It must be nice to be on vacation. Do you do that often? I hope to take five days off this August and I am looking forward to it; it will be my first vacation in almost 14 years.

Anyhow, regarding your questions.....my answers are: it depends, most of the time, probably not, and none.

I might be a bit more detailed, but your snide remark suggesting I would “dance around your questions” annoyed me. You are obviously fishing, Fishing for what? Do you really understand the issues regarding a “thick anti-microbial coating” on the underside of an OSB or plywood floor over a crawl space?

Hello ,

I have been on vacation, but wanted to check to see if you responded to my question about how well the wood building materials needed to be cleaned prior to coating? I did not see a serious answer in screening the emails. Are you even testing prior to coating? Please don't dance around the question. We rec coating when it is needed, but only after cleaning as best practical and surface testing.

Question about the under side of the wood flooring systems in crawl spaces -- is there a real concern about a thick anti microbial coating on the OSB or plywood, say a PERM of 2 to 6?

PS -- What is your procedure for making sure the building owner maintains the coating?

Bradley Harr

Sr. Environmental Scientist

Re: [sPAM] Re: s 40-80 and 40-20

Wayne:

FYI, there are some silica and siloxane-based coatings that are used primarily in the ceramics industry, that are used for their non-penetrating, bridging encapsulant-like properties, and these products have PERM ratings of 45 to 50. I have used these products on CMU wall systems after abating LBP where we needed a high PERM thin-film surface encapsulant that had high solids content and was compatible to the facility’s use. They worked well and performed as anticipated.

While I agree that most folks in the environmental industry have a rather myopic approach to what constitutes an encapsulant, the breadth of encapsulant-like products that are available is very broad. Yes, most IEPs think of, specify, and use a narrow list of encapsulants that typically have PERM ratings lass than 10, and some encapsulants can classify as a vapor barrier with a PERM rating than 1. It doe not have to be so limited, and it really depends; sometimes a low PERM encapsulant is warranted. I have applied coatings that have been nominal-DFT 140-mil thick and I know for a fact that the PERM rating is much less than 1.

I would like to add that s 40-20 is but one product available to us IEPs. I see it used often, and I rarely see it applied to a dry nominal thickness of 11-mils – per s spec. Usually, I see it applied 2 to 3-mils thick, and sometimes it is 4 to 5-mils. (I collect coupons and mic the film and/or use a penetrometer to measure the thickness of the coating.) So....if the manufacture specifies 11-mil nominal DFT (dry film thickness), and it’s in-the-field average thickness is much less.....what is the PERM as-applied? Probably much less than 6. Moreover, if the thickness is not what the manufacturer specifies, is it TOTALLY ineffective? Is it TOTALLY ineffective as an encapsulant? I say no, because it depends. I also know for a fact that manufacturers often specify thick coatings, not because their product is less effective with thinner coatings, but because more product is used thereby sales are i ncreased. Therefore, it really depends on the intended use and function of the product, i.e., the encapsulant. I tend to prefer high-solid, low VOC, thin-film encapsulants; which tend to have very little effect on system permeability. I do not like applying coatings that are vapor barriers when I do not want a vapor barrier; I want an encapsulant. Therefore, I often specify thinner than mfg spec coatings, e.g., s 40-20.

As I mentioned before, I like diluted Elmers white glue as a cheap encapsulant to lock down potential aerosols and surface coat areas where abatement/demolition has been performed. Elmers glue is basically polyvinyl acetate, water soluble, low-VOC, relatively non-toxic and CHEAP. It is also quite effective as a thin-film encapsulant and very permeable when applied as a thin-film encapsulant; what the PERM rating is I have no idea, I could only guess. Surprisingly, it is also very compatible with many materials we find in the build environment, with the most notable exception of fire-proofing. And it is CHEAP....but I said that already.

Bottom line....I have done my homework and continue to do so, because there is so much to learn.

For what it is worth....

please do your homework.

no coating/paint/encapsulant is " like Tyvek " -- not even close!

40-20 (per mfr technical data sheet)

wet film thickness: 20 mils; dry film thickness: 11 mils; permeance: 6 perms at 11 mils DFT

Tyvek: (Spun bonded polyolefin, 0.006 in., 0.013 lb/ft2)

~70 perms (per the mfr, slightly less than 70; per ASHRAE ~76 perms)

other building materials of interest:

1/2 inch gysum wallboard: 55 perms at 50% RH

one inch of still air: 120 perms (the reference point)

6 mil poly sheeting: 0.06 perm

typical latex paints at 1-2 mils DFT: 5-8 perms

1/2 inch OSB: ~0.6 perms at 50% RH

1/2 inch plywood: 1 perm at 50% RH

those quoted " at 50% " demonstrate variable permeability based on installed conditions.

for more see: 2005 ASHRAE Handbook of Fundamentals, Chapter 25

also see: ASHRAE Research Project RP-1018, " A Thermal and Moisture Transport Property Database for Common Building and Insulating Materials " , July 2002

Wane

<><><><><><><><><><><>

Wane A. Baker, P.E., CIH

Division Manager, Indoor Air Quality

MICHAELS ENGINEERING

" Real Professionals. Real Solutions. "

St. , La Crosse, Milwaukee

Phone , ext. 484

Cell

Fax

mailto:wab@...

On the web at: http://www.michaelsengineering.com <http://www.michaelsengineering.com/>

" To love what you do and feel that it matters - how could anything be more fun? "

- Graham

[Guest guest]

Hello ,

Yes, I'm fishing for good information. I also fished on my vacation at Lake . You need more vacations!!!

I said very early on that I was very interested in the coating discussion. As you see by the discussions, there are strong opinions both ways. Coatings cost money and if cleaning / removal is good, why coat? I think Jeff May has a great point -- it reduces the migration of all the very fine allergen particles, which we seldom test for. Pat M has a great point, who is going to properly maintain the coating if it is indeed a needed part of the building treatment? Jim White has a great point in that we should not add toxic chemicals to the indoor enviro. if they are not really needed. ge likes to remove more wood and clean all sides so there is less mold left, but how clean and how expensive. The lawyers like all the confusion and arguments.

I try to write RC guidelines that are practical, but protective. I have RC's in the area that will not use biocides or coatings because EPA and IIcRC S520 don't rec them, plus they are not lic. to apply. Their bids are often high due to more building demo. The home owners often like it, but more demo, means more time out of the building and more build back and I think often a bigger mess, asbestos, lead paint, fiberglass, dust, pollen, more damaged pipes, and all the other junk in building materials.

If you think I have a bad opinion of RC's you are very wrong. I am just a realist, and see what happens on these projects. For example, you made a comment about the loss of RC focus I discussed, this issue is very real and happens on big jobs where crews are over worked. We did 60 buildings on a gov. site and the highest degree of not passing PRV was on the buildings completed on Fridays. 60 % of the buildings cleaned and finished on Fridays failed PRV. Also on 5000 to 10,000 sq ft buildings the last 25% of the area cleaned is more likely to fail. I have no desire to fail RC's and go back and forth on projects.

The PRV gets more expensive when we are working hard to inspect everything in detail. I hate to send the RC back to clean small areas that might be best addressed through a good coating on the area. I can not find all the areas they miss. Plus coating will get the added benefit Jeff May is talking about.

So... I'm working to find a reasonable point of diminishing return on mold cleaning / removal from wood, where coating is cost effective. The dilute Elmer's glue is interesting, but there is really no future building protection, which IMHO you get with or Aftershock. Many of my clients often say, how can we reduce the potential of this happening again? The keep it dry is too simple, buildings flood all the time, over and over.

So, yes I'm fishing, and I think you are having too much fun dancing / toying with me. I have RC's who will not coat crawl space wood because it changes the building design / PERM of the sub floor. That's why I asked. I'm not seeing what they are worried about. Does the request need to be from an engineer or Arcitect who is trained in design issues ? Does not seem that complex to me.

Write me a great response full of good facts and then take the Kids on vacation!! Just joking, don't get grumpy!

Bradley HarrSr. Environmental Scientist

Re: [sPAM] Re: s 40-80 and 40-20 Wayne:FYI, there are some silica and siloxane-based coatings that are used primarily in the ceramics industry, that are used for their non-penetrating, bridging encapsulant-like properties, and these products have PERM ratings of 45 to 50. I have used these products on CMU wall systems after abating LBP where we needed a high PERM thin-film surface encapsulant that had high solids content and was compatible to the facility’s use. They worked well and performed as anticipated.While I agree that most folks in the environmental industry have a rather myopic approach to what constitutes an encapsulant, the breadth of encapsulant-like products that are available is very broad. Yes, most IEPs think of, specify, and use a narrow list of encapsulants that typically have PERM ratings lass than 10, and some encapsulants can classify as a vapor barrier with a PERM rating than 1. It doe not have to be so limited, and it really depends; sometimes a low PERM encapsulant is warranted. I have applied coatings that have been nominal-DFT 140-mil thick and I know for a fact that the PERM rating is much less than 1.I would like to add that s 40-20 is but one product available to us IEPs. I see it used often, and I rarely see it applied to a dry nominal thickness of 11-mils – per s spec. Usually, I see it applied 2 to 3-mils thick, and sometimes it is 4 to 5-mils. (I collect coupons and mic the film and/or use a penetrometer to measure the thickness of the coating.) So....if the manufacture specifies 11-mil nominal DFT (dry film thickness), and it’s in-the-field average thickness is much less.....what is the PERM as-applied? Probably much less than 6. Moreover, if the thickness is not what the manufacturer specifies, is it TOTALLY ineffective? Is it TOTALLY ineffective as an encapsulant? I say no, because it depends. I also know for a fact that manufacturers often specify thick coatings, not because their product is less effective wit h thinner coatings, but because more product is used thereby sales are i ncreased. Therefore, it really depends on the intended use and function of the product, i.e., the encapsulant. I tend to prefer high-solid, low VOC, thin-film encapsulants; which tend to have very little effect on system permeability. I do not like applying coatings that are vapor barriers when I do not want a vapor barrier; I want an encapsulant. Therefore, I often specify thinner than mfg spec coatings, e.g., s 40-20.As I mentioned before, I like diluted Elmers white glue as a cheap encapsulant to lock down potential aerosols and surface coat areas where abatement/demolition has been performed. Elmers glue is basically polyvinyl acetate, water soluble, low-VOC, relatively non-toxic and CHEAP. It is also quite effective as a thin-film encapsulant and very permeable when applied as a thin-film encapsulant; what the PERM rating is I have no idea, I could only guess. Surprisingly, it is also very compatible with many materials we find in the build environment, with the most notable exception of fire-proofing. And it is CHEAP....but I said that already.Bottom line....I have done my homework and continue to do so, because there is so much to learn.For what it is worth....On 6/14/07 10:01 PM, "Wane A. Baker" <wabmichaelsengineering> wrote:

please do your homework. no coating/paint/encapsulant is "like Tyvek" -- not even close! 40-20 (per mfr technical data sheet)wet film thickness: 20 mils; dry film thickness: 11 mils; permeance: 6 perms at 11 mils DFTTyvek: (Spun bonded polyolefin, 0.006 in., 0.013 lb/ft2)~70 perms (per the mfr, slightly less than 70; per ASHRAE ~76 perms)other building materials of interest: 1/2 inch gysum wallboard: 55 perms at 50% RHone inch of still air: 120 perms (the reference point)6 mil poly sheeting: 0.06 permtypical latex paints at 1-2 mils DFT: 5-8 perms1/2 inch OSB: ~0.6 perms at 50% RH1/2 inch plywood: 1 perm at 50% RHthose quoted "at 50%" demonstrate variable permeability based on installed conditions. for more see: 2005 ASHRAE Handbook of Fundamentals, Chapter 25also see: ASHRAE Research Project RP-1018, "A Thermal and Moisture Transport Property Database for Common Building and Insulating Materials", July 2002Wane<><><><><><><><><><><> Wane A. Baker, P.E., CIH Division Manager, Indoor Air Quality MICHAELS ENGINEERING"Real Professionals. Real Solutions." St. , La Crosse, Milwaukee Phone , ext. 484 Cell Fax mailto:wabmichaelsengineering <mailto:wabmichaelsengineering> On the web at: http://www.michaelsengineering.com <http://www.michaelsengineering.com/> "To love what you do and feel that it matters - how could anything be more fun?" - Graham

[Guest guest]

Hello Bob,

What are your basic criteria for cleaned wood surfaces? I have tested outdoor surfaces (trying to est. background) and they are surprisingly low 0 to 200 spores/ cm2. And are you testing for fine fragments which are high in allergens, ie Jeff May's issue?

Bradley HarrSr. Environmental Scientist

Re: [sPAM] Re: s 40-80 and 40-20 Brad:It must be nice to be on vacation. Do you do that often? I hope to take five days off this August and I am looking forward to it; it will be my first vacation in almost 14 years.Anyhow, regarding your questions.....my answers are: it depends, most of the time, probably not, and none.I might be a bit more detailed, but your snide remark suggesting I would “dance around your questions” annoyed me. You are obviously fishing, Fishing for what? Do you really understand the issues regarding a “thick anti-microbial coating” on the underside of an OSB or plywood floor over a crawl space?On 6/18/07 1:53 PM, "Brad Harr" <bdharrsummitenviroinc> wrote:

Hello ,I have been on vacation, but wanted to check to see if you responded to my question about how well the wood building materials needed to be cleaned prior to coating? I did not see a serious answer in screening the emails. Are you even testing prior to coating? Please don't dance around the question. We rec coating when it is needed, but only after cleaning as best practical and surface testing. Question about the under side of the wood flooring systems in crawl spaces -- is there a real concern about a thick anti microbial coating on the OSB or plywood, say a PERM of 2 to 6? PS -- What is your procedure for making sure the building owner maintains the coating?Bradley HarrSr. Environmental Scientist