Re: Re: How to predict if mold will grow inside of gypsum wallboard-faced walls

[Guest guest]

Barb & Jill

Knowing the RH inside the walls, like moisture in the wall itself,

may be useful but it varies with time and sources of moisture.

The accurate and overall representative readings you and others

are looking for requires many measurements over an extended

period of time during different weather and occupant use

conditions. They only tell you the level right then. It doesn't give a

history, nor does it predict. Therefore they don't know if mold is in

the wall - only moisture levels right then.

Moisture meters come in two types: Penetrating (pins push into

the wall leaving tiny holes) and non-penetrating (no pins but

limited in depth). Both use a surogate for moisture and can give a

positive reading that is false from metal, wiring and a few other

conditions.

They are calibrated for wood. So direct readings on wallboard or

floor tile, etc, are not accurate - but they can be compared to

readings from the same material that is known to be dry.

As with all measurement devices you need to know how they

measure, what they measure, the limitations and how you can get

false positives and false negatives. They are not an all-knowing

diety, they require our interpretation.

Prices range from $20 for a simple penetrating alarm to $1000+

for sophisticated ones with multiple optional detecting pins. At

least $100 for a decent non-penetrating type. A quick Google on

" moisture meters " found a penetrating type by Exetech for $80 at

Sears, but is out of stock. Check out

http://www.moisturemeterstore.com/ and other Google results for

a quick idea of what is available.

Measuring RH inside walls is even more difficult. Keep in mind

that sticking the tip of a meter through the opening for an

electrical outlet could subject you to electrical shock and the RH

may be a combination of what is deeper inside the wall as it

mixes with air from the room. Even cutting a hole in the middle of

the wall can quickly alter the RH (the " R " is for " relative " which

means it is a comparison to something, which can quickly

change). Again, knowing what it does, doesn't do and limitations

are important.

I don't mean to discourage, but to emphasize there is no

definitive measuring device that answers the question of " is there

a problem for me " in this building. False hope is worse than truth

we'd rather not know about.

Carl Grimes

Healthy Habitats LLC

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> Sounds reasonable. Sounds like a test one could do looking for a new

> home or apartment.

> How would a homeowner test this, putting the tip of a home humidity

> guage inside of wall through wall outlet would do the test, using one

> of those moisture meters that you press on the wall. Incidentally

> I'd like to get one. Does anyone have a recommendation of something

> reasonably priced but reliable?

>

>

> >

> > Barb,

> >

> > This is an interesting paper that does the work of predicting

> whether

> > stachybotrys mold will grow in a wall or produce mycotoxins inside

> the wall

> > that accumulate there.

> >

>

> ------------------------------------

>

> FAIR USE NOTICE:

>

>

[Guest guest]

Yes, Barb, you've " got it! "

BTW, the differences you noted apply to Infrared cameras used

for finding " moisture " that someone mentioned. They actually

measure temperature differences. If the water is cooler or

warmer than the wall, floor or ceiling the camera shows a

different color or shade of gray. But in the middle of the day or

night when both are the same temp it won't show up.

Carl Grimes

Healthy Habitats LLC

-----

> Thanks Carl. I totally understand and it makes sense. Moisture would

> have to be high for a long enough period to start mold growth and to

> keep it up. It could be high during the night when temperatures drop

> but dry out sufficiently during the day when it's hot or inside factors

> as well. I also know understand the term 'inflamation'. I thought my

> doctor was saying the two could not be present at same time, it was

> either infected or inflamed. Got it!

>

>

> >

> > Barb & Jill

> >

> > Knowing the RH inside the walls, like moisture in the wall itself,

> > may be useful but it varies with time and sources of moisture.

>

>

>

> ------------------------------------

>

> FAIR USE NOTICE:

>

>

[Guest guest]

Jill,

From your description the wall cavity is screwed up. Testing won't

change the need to stop the leaks and remove the damaged

material. But if testing is done improperly and you get negative

results (or what others insist to be negative) then you lose.

Because you rent the landlord has to be involved. If the landlord

refuses to help then you, like the wall cavity, are screwed. You

either get the work done at your expense and without the

landlord's knowledge - NOT recommended! - or you move.

Sealing off the walls, etc, could help some, maybe enough for a

little while. You'd have to experiment with which sealants and

caulks are least reactive for you. They will outgas much faster

than the wall will heal itself so the risk, long term, is much lower.

Carl Grimes

Healthy Habitats LLC

-----

It was me who mentioned the infrared sensor, Carl, as it was in a

bookon toxic mold by a D.O, M Beth Short-Ray. I think she had

aspergillus in her home and stachy at work. Sort of a double

whammy but for all we know lots of people have mold at home

and work.

I just can't figure out how I'm supposed to remediate my small

bedroom without great expense or fanfare or involving the

landlord. As I said, I went through major demolition in this bldg

with 10 leaks and floods in my apt alone of various magnitude

(two were major) and though I aired out, who knows what's really

left in there esp in a relatively humid place like NYC. In addition,

they tore up the floors including the dirt insulation, throughout the

bldg, and god knows what spores of this or that were released

and settled in various places. Three apartments over me were

gut demolished and renovated.

In any case, I know there's something wrong in that room on the

west wall where the windows are, I found dry rot when I busted

up and removed the inbuilt shelving, I'm thinking of removing the

wood " molding " on the sill which still had a bit of dry rot, but

beyond that I don't know what to do. The room doesn't smell

right. I could ozonate it (I have an ozone machine). I know you

said testing is really not that significant if you know you have a

problem and you're reacting, you must remediate. Your colleague

in NJ suggested sealing off everything. That would mean I guess

shellacking the walls and caulking up every little nook or cranny

but I'm MCS and that thought is not so pleasing.

If I can't determine if the wall cavity is screwed up what should I

do.

De facto I'm living in a one bedroom apartment now as i never

use that room. Its summer now and a good time to remediate

because its still hot and you can keep windows open. Etc.

>

> Yes, Barb, you've " got it! "

>

> BTW, the differences you noted apply to Infrared cameras used

> for finding " moisture " that someone mentioned. They actually

> measure temperature differences. If the water is cooler or

> warmer than the wall, floor or ceiling the camera shows a

> different color or shade of gray. But in the middle of the day or

> night when both are the same temp it won't show up.

>

> Carl Grimes

> Healthy Habitats LLC

>

> -----

> >

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FAIR USE NOTICE:

[Guest guest]

Are you living under some kind of rent-stabilization ordinance? I

guess what I mean is do they have a fnancial incentive to try to drive

you out?

If you had to re-rent your apartment at market rate, assuming you

could, what would be the difference between that rent and your current

rent?

By complaining, you may risk a 'repair' that takes months or years and

requires you to leave, putting all your stuff in storage, on faith

that things will get fixed when they often aren't? (after all, mold is

invsible and there are no real laws that specify how much is okay or

not.. even in NYC.)

Do you have friends you could live with while your apartment is

gutted? You would probably have a right to re-rent at the former rent

plus the cost of the 'improvements' right? Assuming that you don't

rent another place, during that time.

In co-ops they pay to put you up in a hotel, I think, often at a cost

of thousands of dollars. Is your apartment a co-op?

Are there any *affordable* hotels in your neighborhood? How much do

they charge by the week? How much would it cost to put all your

funrniture and other belongings in storage to protect them and you

from being able to sue for anything?

[Guest guest]

Carl,

what about something for the consumer that would measure room humidity? Is there

anything that you would recommend? At least this way for those of us who count

on dehumidifying our homes we can keep better track of how it is working. I have

humidity guage on our upstairs hvac unit, but not on the older one downstairs.

I've gone to Lowe's, Wallmart, Ace and Home Depot and no one hear seems to have

one or know what I'm looking for.

Many Thanks,

Jac

> Knowing the RH inside the walls, like moisture in the wall

> itself,

[Guest guest]

jac,

Humidity meters are available from $3 to hundreds of $$$. Avoid

anything much under $30 because they are notoriously

inaccurate. Not by a little but by a lot. For example, a client had a

$3 round metal humidity meter that looks like a refrigerator

thermometer. On a 90 degree day with the RH below 15% it read

90%. Not even close. Probably reading the temperature instead.

Radio Shack has some electronic humidity meters for around

$30. They are technically known as hygrometers. If you see

thermo-hygrometer it combines temp and RH and most will also

show the dew point.

For the more adventurous among you, check out:

www.dasdistribution.com/products/humidity_meters/index.htm

Carl Grimes

Healthy Habitats LLC

-----

> Carl,

>

> what about something for the consumer that would measure room humidity? Is

there anything that you would recommend? At least this way for those of us who

count on dehumidifying our homes we can keep better track of how it is working.

I have humidity guage on our upstairs hvac unit, but not on the older one

downstairs. I've gone to Lowe's, Wallmart, Ace and Home Depot and no one hear

seems to have one or know what I'm looking for.

>

> Many Thanks,

> Jac

>

>

> > Knowing the RH inside the walls, like moisture in the wall

> > itself,

>

>

>

>

> ------------------------------------

>

> FAIR USE NOTICE:

>

>

[Guest guest]

Thanks Carl! I always appreciate the time you take out of your busy schedule to

help us.

> Humidity meters are available from $3 to hundreds of $$$.

>