Re: s 40-80 and 40-20

[Guest guest]

It is not as simple as just looking at whether the

permeability of a material is under or over 1.

It depends on the part of the country, type of materials,

construction methods, construction errors, building maintenance …

Oak Ridge National Laboratory has a moisture design tool for

architects and engineers with a free download at: http://www.ornl.gov/sci/btc/apps/moisture/

(I understand there is also have a more powerful paid version). Using this

software you can model a wall and then run a simulation to see if moisture will

accumulate in any part of the wall system. If memory serves me correctly it

currently has climate data for running simulations in about 50 major US cities.

By running the model with the paint film present and again without

the paint film you can compare the results and determine if the building is

going to be more likely to develop moisture problems in wall cavities as a

result of the change in permeability introduced by the paint film.

Banta

[Guest guest]

There are quite a few such models that look only at diffusion of moisture (the best are based on Canadian and Finnish research). Unfortunately diffusion is the third most important reason for moisture problems, after wind-driven rain and air leakage. Until you cover the more important moisture problem mechanisms it does not make much sense to do a lot of modeling of the third most important one.

Asking the most important questions is more important than getting an accurate answers to #3.

Jim H. White SSC

Re: s 40-80 and 40-20

It is not as simple as just looking at whether the permeability of a material is under or over 1.

It depends on the part of the country, type of materials, construction methods, construction errors, building maintenance …

Oak Ridge National Laboratory has a moisture design tool for architects and engineers with a free download at: http://www.ornl.gov/sci/btc/apps/moisture/ (I understand there is also have a more powerful paid version). Using this software you can model a wall and then run a simulation to see if moisture will accumulate in any part of the wall system. If memory serves me correctly it currently has climate data for running simulations in about 50 major US cities.

By running the model with the paint film present and again without the paint film you can compare the results and determine if the building is going to be more likely to develop moisture problems in wall cavities as a result of the change in permeability introduced by the paint film.

Banta

[Guest guest]

Jim,

Have you been trained or sat in to

understand the WUFI system? I am waiting for it to come around this area again

(hopefully).

EnviroBob

From: iequality [mailto:iequality ] On Behalf Of Jim H. White

Sent: Thursday, June 14, 2007 4:31

PM

To: iequality

Subject: Re: s

40-80 and 40-20

There are quite a few such models that look only at

diffusion of moisture (the best are based on Canadian and Finnish research).

Unfortunately diffusion is the third most important reason for moisture

problems, after wind-driven rain and air leakage. Until you cover the more

important moisture problem mechanisms it does not make much sense to do a lot

of modeling of the third most important one.

Asking the most important questions is more important than

getting an accurate answers to #3.

Jim H. White SSC

Re:

s 40-80 and 40-20

It is not as

simple as just looking at whether the permeability of a material is under or

over 1.

It depends

on the part of the country, type of materials, construction methods,

construction errors, building maintenance …

Oak Ridge

National Laboratory has a moisture design tool for architects and engineers

with a free download at: http://www.ornl.gov/sci/btc/apps/moisture/

(I understand there is also have a more powerful paid version). Using this

software you can model a wall and then run a simulation to see if moisture will

accumulate in any part of the wall system. If memory serves me correctly it

currently has climate data for running simulations in about 50 major US cities.

By running

the model with the paint film present and again without the paint film you can

compare the results and determine if the building is going to be more likely to

develop moisture problems in wall cavities as a result of the change in permeability

introduced by the paint film.

Banta

[Guest guest]

Jim:

All very well said! I use WUFI as one of my moisture models, and in areas with wind-driven rain and/or assemblies that experience significant and sustained pressure-loads, WUFI always underestimates the the moisture movement therein. Though I will state that once moisture gets into an assembly, WUFI does a pretty good job of predicting where the moisture will accumulate and/or condense. This said, wind-driven rain is the devil that no computer model that I am aware of, can predict with any accuracy.

There are quite a few such models that look only at diffusion of moisture (the best are based on Canadian and Finnish research). Unfortunately diffusion is the third most important reason for moisture problems, after wind-driven rain and air leakage. Until you cover the more important moisture problem mechanisms it does not make much sense to do a lot of modeling of the third most important one.

Asking the most important questions is more important than getting an accurate answers to #3.

Jim H. White SSC

Re: s 40-80 and 40-20

It is not as simple as just looking at whether the permeability of a material is under or over 1.

It depends on the part of the country, type of materials, construction methods, construction errors, building maintenance

Oak Ridge National Laboratory has a moisture design tool for architects and engineers with a free download at: http://www.ornl.gov/sci/btc/apps/moisture/ (I understand there is also have a more powerful paid version). Using this software you can model a wall and then run a simulation to see if moisture will accumulate in any part of the wall system. If memory serves me correctly it currently has climate data for running simulations in about 50 major US cities.

By running the model with the paint film present and again without the paint film you can compare the results and determine if the building is going to be more likely to develop moisture problems in wall cavities as a result of the change in permeability introduced by the paint film.

Banta

[Guest guest]

Of course you are right Jim. That is why I said it depends

on construction methods, construction errors, and building

maintenance. I was merely providing a way to help illustrate the difference an

improperly placed paint film can contribute in moisture accumulation in an

otherwise well constructed building, and the problem with thinking that all is

well as long as permeability is over 1.

You are also correct about other models available, but

WUFI is the one I am most familiar with and seemed most appropriate for

illustrating the point.

Thank you for helping me with the clarification.

Banta

[Guest guest]

Bob

No, but I sat in on the development of a number of such models. As says they are good at predicting where water will show up once it is in the assembly, because internal transfers are often by diffusion. However, the amount of moisture that can be in an assembly where air leaks are large and wind-driven rain is present can be off by about two decimal orders of magnitude.

Jim H. White

System Science Consulting

Re: s 40-80 and 40-20

It is not as simple as just looking at whether the permeability of a material is under or over 1.

It depends on the part of the country, type of materials, construction methods, construction errors, building maintenance …

Oak Ridge National Laboratory has a moisture design tool for architects and engineers with a free download at: http://www.ornl.gov/sci/btc/apps/moisture/ (I understand there is also have a more powerful paid version). Using this software you can model a wall and then run a simulation to see if moisture will accumulate in any part of the wall system. If memory serves me correctly it currently has climate data for running simulations in about 50 major US cities.

By running the model with the paint film present and again without the paint film you can compare the results and determine if the building is going to be more likely to develop moisture problems in wall cavities as a result of the change in permeability introduced by the paint film.

Banta

[Guest guest]

Et al,

I think there was/is someone on this list

who has been trained to utilize the WUFI model; is that correct. I would like

to hear your opinion of the system’s projections. I would like to hear of

its limitations as well its abilities.

EnviroBob

From:

iequality [mailto:iequality ] On Behalf Of Jim H. White

Sent: Friday, June 15, 2007 1:55

PM

To: iequality

Subject: Re: s

40-80 and 40-20

Bob

No, but I sat in on the development of a number of such

models. As says they are good at predicting where water will show up

once it is in the assembly, because internal transfers are often by diffusion.

However, the amount of moisture that can be in an assembly where air leaks are

large and wind-driven rain is present can be off by about two decimal orders of

magnitude.

Jim H. White

System Science Consulting

Re: s 40-80 and 40-20

It is not as

simple as just looking at whether the permeability of a material is under or

over 1.

It

depends on the part of the country, type of materials, construction methods,

construction errors, building maintenance …

Oak

Ridge National Laboratory has a moisture design tool for architects and

engineers with a free download at: http://www.ornl.gov/sci/btc/apps/moisture/

(I understand there is also have a more powerful paid version). Using this

software you can model a wall and then run a simulation to see if moisture will

accumulate in any part of the wall system. If memory serves me correctly it

currently has climate data for running simulations in about 50 major US

cities.

By

running the model with the paint film present and again without the paint film

you can compare the results and determine if the building is going to be more

likely to develop moisture problems in wall cavities as a result of the change

in permeability introduced by the paint film.

Banta

[Guest guest]

Et al,

I think there was/is someone on this list

who has been trained to utilize the WUFI model; is that correct. I would like

to hear your opinion of the system’s projections. I would like to hear of

its limitations as well its abilities.

EnviroBob

From:

iequality [mailto:iequality ] On Behalf Of Jim H. White

Sent: Friday, June 15, 2007 1:55

PM

To: iequality

Subject: Re: s

40-80 and 40-20

Bob

No, but I sat in on the development of a number of such

models. As says they are good at predicting where water will show up

once it is in the assembly, because internal transfers are often by diffusion.

However, the amount of moisture that can be in an assembly where air leaks are

large and wind-driven rain is present can be off by about two decimal orders of

magnitude.

Jim H. White

System Science Consulting

Re: s 40-80 and 40-20

It is not as

simple as just looking at whether the permeability of a material is under or

over 1.

It

depends on the part of the country, type of materials, construction methods,

construction errors, building maintenance …

Oak

Ridge National Laboratory has a moisture design tool for architects and

engineers with a free download at: http://www.ornl.gov/sci/btc/apps/moisture/

(I understand there is also have a more powerful paid version). Using this

software you can model a wall and then run a simulation to see if moisture will

accumulate in any part of the wall system. If memory serves me correctly it

currently has climate data for running simulations in about 50 major US

cities.

By

running the model with the paint film present and again without the paint film

you can compare the results and determine if the building is going to be more

likely to develop moisture problems in wall cavities as a result of the change

in permeability introduced by the paint film.

Banta

[Guest guest]

Mychael:

Wow! That horse of yours is pretty darn high, isn't it?

Why would someone who has "done their homework" make these statements?

1. "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)."

How can one possibly suggest that a coating at 4 perms is analogous to Tyvek at 70 perms? Please compare those numbers to the permeability of air (which I provided in my post) and you'll get the point.

1" of air: ~120 perms

Tyvek: ~70 perms

typ. coating (per this conversation): ~4-6 perms

Strictly speaking, very few materials are "vapor barriers" -- most fall within the spectrum of vapor retarders. Use of the term vapor barrier is essentially obsolete, except for materials like sheet metal or glass.

For further edification, please see Lstiburek's writings on vapor retarders. Those interested can send a private email to <wab-at-sEngineering.com> for specific cites to the literature.

-and-

2. "So....if the manufacture [sic] specifies 11-mil nominal DFT (dry film thickness), and it¹s [sic] in-the-field average thickness is much less.....what is the PERM as-applied? Probably much less than 6."

No....that's backwards. Any coating applied at 6 mils vs. the specified 11 mils DFT would yield a HIGHER permeance.

As for the rest of your reply, where do you find the time to write this stuff? I can't figure out who you're trying to impress.

You're a bright guy, Myke, and very passionate. But holy cow, order up some humility will ya? When you're wrong, you're wrong.

When we get the facts right 95% of the time, but botch up the other 5% (or pull it out of our ear) we still do more harm than good on this list.

Wane

PS1: Once, I thought I was wrong, but I was mistaken. <g>

PS2: Around here, it's "where the rubber meets the road"

PS3: This is not "material's [sic] science"; it's building physics. A good place to start would be to understand the distinction between permeance and permeability. Asking "what is the PERM" doesn't mean anything; it's like saying "what is the gr/ft2-hr-in Hg".

> >> >> >> > ,> >> > > >> > 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:

Yes, I was wrong. When I was mentioning coatings with in-the-field applied thickness less than the manufacturer’s recommendations, I was thinking more permeance, but wrote less PERM. Thanks for the correction. BTW....I don’t hang my hat on any “typical” coating. There are a lot of materials to choose from when a coating may be appropriate; s and Fiberlock are just examples of products typically used in the environmental scene, but there are other products not necessarily thought of as an encapsulant, that function very similarly. And based on the circumstances of the situation, these other products warrant consideration. Tis was the foundation of my post; not PERM ratings. Thanks again for the correction.

But where do you get off by sating that vapor barriers are obsolete? Maybe you didn’t get off, but missed the boat. Vapor barriers are alive and well, and their use in construction is increasing because their function is being recognized. Try paying attention to Flexible Membrane Liners (FMLs) in construction. You may catch a wonderful ride.

Regarding Lstiburek.......Yes, I believe he has some good stuff, really good stuff. But I also find fault too. Sometimes I believe he needs to be in the field more, because there are, at times, a lack of practicality in his recommendations. Moreover, in different parts of the country, the cookie-cutter approach is not always applicable and all too often I see folks use Lstiburek’s recommendations without thought. Also, I have an issue with Lstiburek still recommending damp-proofing below-grade walls, a method I find of very little long-term value. Ever excavate a foundation that has been damp-proofed 10yrs after the damp-proofing has been applied? It is often worthless. If below-grade foundations intend to stay dry, they need more than damp-proofing, they need a vapor barrier, e.g., an FML. I design and install FMLs often, they work, they are passive, and they will last the life of the structure. FMLs out-perform damp-proofing hands down!

Regarding my horse......He is 16 hands high. A really big guy! And powerful too. Nice butt. But, IMHO, most Quarter Horses have a nice butt.

Mychael:

Wow! That horse of yours is pretty darn high, isn't it?

Why would someone who has " done their homework " make these statements?

1. " 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). "

How can one possibly suggest that a coating at 4 perms is analogous to Tyvek at 70 perms? Please compare those numbers to the permeability of air (which I provided in my post) and you'll get the point.

1 " of air: ~120 perms

Tyvek: ~70 perms

typ. coating (per this conversation): ~4-6 perms

Strictly speaking, very few materials are " vapor barriers " -- most fall within the spectrum of vapor retarders. Use of the term vapor barrier is essentially obsolete, except for materials like sheet metal or glass.

For further edification, please see Lstiburek's writings on vapor retarders. Those interested can send a private email to <wab-at-sEngineering.com> for specific cites to the literature.

-and-

2. " So....if the manufacture [sic] specifies 11-mil nominal DFT (dry film thickness), and it’s [sic] in-the-field average thickness is much less.....what is the PERM as-applied? Probably much less than 6. "

No....that's backwards. Any coating applied at 6 mils vs. the specified 11 mils DFT would yield a HIGHER permeance.

As for the rest of your reply, where do you find the time to write this stuff? I can't figure out who you're trying to impress.

You're a bright guy, Myke, and very passionate. But holy cow, order up some humility will ya? When you're wrong, you're wrong.

When we get the facts right 95% of the time, but botch up the other 5% (or pull it out of our ear) we still do more harm than good on this list.

Wane

PS1: Once, I thought I was wrong, but I was mistaken. <g>

PS2: Around here, it's " where the rubber meets the road "

PS3: This is not " material's [sic] science " ; it's building physics. A good place to start would be to understand the distinction between permeance and permeability. Asking " what is the PERM " doesn't mean anything; it's like saying " what is the gr/ft2-hr-in Hg " .

> >> >

> >> > ,

> >> >

> >> > 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

> >> >

> >> >

> >> >

[Guest guest]

A few comments on you message to Wane, especially the following:

"But where do you get off by sating that vapor barriers are obsolete? Maybe you didn’t get off, but missed the boat. Vapor barriers are alive and well, and their use in construction is increasing because their function is being recognized. Try paying attention to Flexible Membrane Liners (FMLs) in construction. You may catch a wonderful ride."C1 Vapor barriers are almost always a bad thing in construction assemblies; vapor retarders can be a good thing IFF they have a high-enough Perm rating (knowing what 'high-enough' is going to be is the hard part. Achilles program would be useful here.). To stop moisture movement in assemblies that are present on a water planet with vapor barriers usually results in a condensation problem during at least a part of the season;

C2 Vapor 'barriers' ended up in the building code only because the diffusion of moisture through materials was easier to calculate, not because it was important. In most assemblies that have gotten into moisture problems it is responsible for only about 1-5% of the moisture flow. Even now we are having trouble modeling air flow and wind-driven water flow well enough. I have been preaching that a poor modeling attempt of the 95% effect is better than 99.97% accurate modeling of the 5% effect. Our National Building Code now takes this more seriously in that air barriers are required, not just recommended. Note that, in Canada at least, air/vapour barriers were an attempt to make one material perform both the vapor diffusion control and the air barrier control. This was always a bad idea (since the driving pressures and flow mechanisms were different), but lasted for over a decade. Codes change slowly, even when badly formulated.

C3 What you are referring to with FMLs are likely acting as waterproofing layers, not a diffusion layers. Below grade that is almost always a good thing. Many assemblies in many soils need a waterproofing layer to have the assembly stay out of trouble for decades. Codes still do not state this requirement forcefully/well enough! In Canada the industry associations strongly resist the real needs being studied well enough to provide definitive research support for good code language. The people of Canada then pay with wet basements!

Re your sentence

"Also, I have an issue with Lstiburek still recommending damp-proofing below-grade walls, a method I find of very little long-term value."

I have the following comment:

C4 I think that you do not understand Joe's requirement for damp-proofing; he wants that done with materials that do the job for decades, not with a poorly-applied asphalt coating that breaks down quickly in many soils. I am with you in that I seldom see damp-proofing asphaltic coatings in working order in any excavation episodes that I have seen; the Greater Ottawa Area soils seem to love it as food! As the Newfies would say "There it is; gone!"

Jim H. White System Science Consulting

Re: s 40-80 and 40-20

Wayne:Yes, I was wrong. When I was mentioning coatings with in-the-field applied thickness less than the manufacturer’s recommendations, I was thinking more permeance, but wrote less PERM. Thanks for the correction. BTW....I don’t hang my hat on any “typical” coating. There are a lot of materials to choose from when a coating may be appropriate; s and Fiberlock are just examples of products typically used in the environmental scene, but there are other products not necessarily thought of as an encapsulant, that function very similarly. And based on the circumstances of the situation, these other products warrant consideration. Tis was the foundation of my post; not PERM ratings. Thanks again for the correction.But where do you get off by sating that vapor barriers are obsolete? Maybe you didn’t get off, but missed the boat. Vapor barriers are alive and well, and their use in construction is increasing because their function is being recognized. Try paying attention to Flexible Membrane Liners (FMLs) in construction. You may catch a wonderful ride.Regarding Lstiburek.......Yes, I believe he has some good stuff, really good stuff. But I also find fault too. Sometimes I believe he needs to be in the field more, because there are, at times, a lack of practicality in his recommendations. Moreover, in different parts of the country, the cookie-cutter approach is not always applicable and all too often I see folks use Lstiburek’s recommendations without thought. Also, I have an issue with Lstiburek still recommending damp-proofing below-grade walls, a method I find of very little long-term value. Ever excavate a foundation that has been damp-proofed 10yrs after the damp-proofing has been applied? It is often worthless. If below-grade foundations intend to stay dry, they need more than damp-proofing, they need a vapor barrier, e.g., an FML. I design and install FMLs often, they work, they are passive, and they will last the life of the structure. FMLs out-perform damp-proofing hands down!Regarding my horse......He is 16 hands high. A really big guy! And powerful too. Nice butt. But, IMHO, most Quarter Horses have a nice butt.On 6/18/07 10:42 PM, "Wane A. Baker" <wabmichaelsengineering> wrote:

Mychael: Wow! That horse of yours is pretty darn high, isn't it? Why would someone who has "done their homework" make these statements?1. "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)."How can one possibly suggest that a coating at 4 perms is analogous to Tyvek at 70 perms? Please compare those numbers to the permeability of air (which I provided in my post) and you'll get the point. 1" of air: ~120 permsTyvek: ~70 permstyp. coating (per this conversation): ~4-6 permsStrictly speaking, very few materials are "vapor barriers" -- most fall within the spectrum of vapor retarders. Use of the term vapor barrier is essentially obsolete, except for materials like sheet metal or glass. For further edification, please see Lstiburek's writings on vapor retarders. Those interested can send a private email to <wab-at-sEngineering.com> for specific cites to the literature. -and- 2. "So....if the manufacture [sic] specifies 11-mil nominal DFT (dry film thickness), and it’s [sic] in-the-field average thickness is much less.....what is the PERM as-applied? Probably much less than 6." No....that's backwards. Any coating applied at 6 mils vs. the specified 11 mils DFT would yield a HIGHER permeance. As for the rest of your reply, where do you find the time to write this stuff? I can't figure out who you're trying to impress. You're a bright guy, Myke, and very passionate. But holy cow, order up some humility will ya? When you're wrong, you're wrong. When we get the facts right 95% of the time, but botch up the other 5% (or pull it out of our ear) we still do more harm than good on this list. WanePS1: Once, I thought I was wrong, but I was mistaken. <g>PS2: Around here, it's "where the rubber meets the road"PS3: This is not "material's [sic] science"; it's building physics. A good place to start would be to understand the distinction between permeance and permeability. Asking "what is the PERM" doesn't mean anything; it's like saying "what is the gr/ft2-hr-in Hg". > >> >> >> > ,> >> > > >> > 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> >> > > >> > > >> >

[Guest guest]

EnviroBob:

In most situations......No; I don’t believe it is possible. This said, I know (based on experience) that if you only collect 75 liters of air in a really clean environment, you will get non-detects in some samples. And if your sample set is small, the environment may appear to be spore-free. Try collecting 1,000 to 2,000 liters of air in a clean environment and see what you get...spores. This said, I have monitored semi-conductor FAB rooms and I was amazed how clean the air was. However, let it be known that they work real hard, and spend a lot of money, to make it nearly particulate (and spore) free.

,

You wrote: Even the EPA has published guidelines stating that all sources of mold must be removed. I find this position/opinion impractical, because if all sources were removed then one could infer sterility.

My reply: the EPA is not saying all spores require removal as we know mold spores are ubiquitous. What the EPA (I believe) is saying is all molds and mold growth is required to be removed. The spores also need to be reduced to at least background rank and order. As you know, all molds are an allergen.

On the other side, if a contained area is sealed off as one posting participant (barb) has been attempting to accomplish; do you feel it is possible to remove all or at least get to a point (after sealing off leaks) where spores are not detected?

EnviroBob

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

Sent: Wednesday, June 20, 2007 11:32 AM

To: iequality

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

Brad:

I very much appreciate you spending the time to clarify your earlier post – you were fishing with intent and merit. BTW, is Lake a good fishing spot? Not that I am going to run out there to dip my line, but seems so inviting.

Anyhow...my thoughts on coatings and mold cleanup....

If you have not noticed already, I argue all the time with the folks I refer to as “source removal advocates.” Even the EPA has published guidelines stating that all sources of mold must be removed. I find this position/opinion impractical, because if all sources were removed then one could infer sterility. Moreover, there are often interstitial spaces within building assemblies that cannot be cleaned of mold (or any other biomass for that matter) without demolishing/disassembling the structure into its individual functional elements and cleaning each an every piece individually; which is also impractical. Therefore, source removal advocates, are you demolishing/disassembling structures to clean all sources of mold, or are you doing a reasonable level of cleaning and leaving some biomass behind? (A rhetorical question.) This said, if you are leaving some biomass behind, please acknowledge this fact! This then leads to the next question...What are you going to do about the biomass left behind? And this is where the discussion regarding coatings has merit.

However, imbedded herein also lies the question....How clean is clean? I for one do not use a cookie-cutter approach to cleaning and prefer to let the circumstances dictate the level of cleanliness warranted. Is the location a hospital or critical care facility?, a school?, an office building?, a manufacturing facility?, is it someone’s home?, is it a multifamily dwelling?, is there a need for fastidious cleaning?, do the people that live there have poor housekeeping and hygiene practices? I also let the budget drive the clean-up effort – if the mold resulted from an insured loss and the insurance company has a $5K cap on payments, then there is only $5K in the clean-up budget; unless a pot of gold or philanthropist shows up. These circumstances all have a bearing on how clean is necessary, how much needs to be removed, and how much can be left behind. And if some biomass is left behind, how can it be safely left behind. This again, is where a discussion regarding coatings has merit.

All this said, let me also comment on some of the elements mentioned in your post. You stated that coatings cost money. Yes they do; everything does. But coatings, more often than not, are a very minor percentage of the overall project cost; not insignificant, but minor. Yet an effective coating can provide significant value to the completed project. Minor percentage of cost = significant overall project value. Hmmm. Yes, I agree with Jeff May, demolition involves disturbing a lot of materials, many of which the IEPs are not paying attention to or testing for, and a coating (if effective) does a fine job of mitigating fine aerosols; which are asthma triggers just as mold spores are. I do not agree with Pat that an environmental coating (an encapsulant) needs to be maintained in most instances. The paint system on the outside of my home needs to be maintained AND I have access to maintain it. But an encapsulant inside my hollow-cavity wall system post-mold remediation is a once-shot product that does not warrant maintenance. What are folks to do....remove their drywall system every couple of years to apply a new coating of s to maintain the coating? Get real! Moreover, if the coating warrants maintenance, then it becomes part of the overall building assembly and it needs to be compatible with the long-term aspects and function of that assembly. Jim’s comment regarding toxicity has merit and fallacy. Yes, we should reduce the application/use of products into our environment that have a toxic effect, but the term “toxic” is so overblown and over-used. Maybe we should stop putting gasoline into our cars because gasoline is very toxic, very flammable, explosive, and damages the environment? (Another rhetorical question.) Most coatings and encapsulants when dry are relatively non-toxic. Moreover, if they are applied to surfaces that do not come into contact with the occupants, is there a hazard? Also, I must disagree with your comment that “buildings flood all the time, over and over.” Not necessarily and not universally. And yes, it is as simple as keeping things dry. However, we live on a water planet, water gives us life, and yes, some areas are prone to flooding – New Orleans is a prime example and they should have anticipated it. (Anyone who lives near the coast, at an elevation below sea level, in a location where there are hurricanes, AND who believes that it will never flood, is not being practical or realistic. Nor should they whine and snivel when it does flood....IMHO. Don’t get me started!) This said, maybe a wood-framed structure with sheetrock covered interior walls and clapboard exterior siding is not the best choice of building materials in these location? What do you think? Maybe the building codes should reflect a better choice of materials in flood-prone areas? Maybe we need so institutional controls? Maybe people should be a bit more realistic about the limitations of building materials? Maybe people should be a bit more realistic that things are going to get wet, on occasion, and things are going to get moldy, on occasion. When it does, clean it up and mush on! To believe that it will never happen, is not very practical or realistic.....but I said that already didn’t I.

Bottom line......coatings (encapsulants) are but a tool to be used when there is merit and value. I do not advocate cleaning to sterility, demolishing to clean, or that every surface needs to be spanky clean. There are budgets, constraints, and limitations that are warranted and important. Do I use/specify coatings on all of my building remediation projects.....No. Most projects...Yes. The types of coatings I use/specify most often......thin-film, permeable, low cost, compatible encapsulants......like PVA. Have I ever used coatings to cover gross contamination without cleaning....Yes.

I hope this put a blip on your fish finder. Nice dialog.

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 Harr

Sr. Environmental Scientist

[Guest guest]

Gentlemen,

Keep in mind that while a cleanroom is extremely particulate free, it

is not sterile. This includes a Class 1 cleanroom utilizing ULPA

and/or HEPA filters. I spent 15 years in the semi-conductor arena

and there is much we can learn from that environment. Temperature,

airflow, air exchange, humidity control, etc. Virus and bacteria can

be circulated througout a facility, even if it is particulate free.

Myself and a few of my associates are preparing to release our

finally finished water leak prevention system for use in homes. This

unit will detect a large rupture or a small pinhole leak they drwall

contractor may have punctured in the water supply line. I recently

had a friend that had a $45,000.00 mold remediation caused by a small

pinhole in the water supply line in their home. The pinhole had been

slowly seeping/dripping for over 10 years undetected!! During that

time the mold was slowly steadily taking over their home.

Regards,

Alonzo Morales

CEO - Microbe Guard of Oregon

> >>

> >>

> >>

> >>

> >>

> >> 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 Harr

> >> Sr. Environmental Scientist

> >>

> >>

> >>

>