Re: Moisture meters

[Guest guest]

Carl,

This is very much appreciated. I am still going through the links you

provided. Thank you so much for taking the time with this. I would like to

get

back to you with a few questions if I may, after I have read up more on this.

In a message dated 7/21/2006 2:15:27 AM Central Standard Time,

grimes@... writes:

, Bill and the group,

For simple screening purposes anyone with simple orientation can use

a meter of some sort. Simple pin-types start at $20-$60 but the non-

penetrating ones start at $280 or so.

As with mold testing, they do not answer the question, " Is there a

mold or moisture 'problem'? " But they are tools (like some mold

testing) that can provide information to help answer that question

and others. As with any instrument, irrespective of cost, you need to

know what it can do, what it can't do, how to interpret the results,

how not to interpret the results and under what conditions.

_http://www.inspectohttp://www.http://www.http_

(http://www.inspectortools.com/pinmoismet.html) has some pin-type

meters starting at about $60. Be aware that these leave holes because

you have to push the pins into the material you are testing. Many

industrial supply houses have a simple one for about $20. It doesn't

have a meter, just an alarm that is preset at a certain level. Pin-

type meters only measure the moisture content (MC) between the two

pins and only as deep as the pins go. Usually 1/2 " or less. Some of

the more expensive models have pins 7 " long so you can measure behind

insulation, for example. A general survey with a pin-type meter will

leave lots and lots of holes that look like snake bites.

Non-penetrating meters won't leave holes because they use a radio

type signal to " measure " the moisture content. A decent one costs at

least $280 (same Web site). Large areas can be quickly checked but,

as Bill mentioned, only to a depth of 1 " or less and not right in the

corners. They also can give false readings, especially from metal

wrap on corners of walls or electical wires and conduit behind

sheetrock.

What will a moisture meter tell you? They measure the moisture

content of the material being tested. Moisture content (MC) is the

percentage of water by weight. That means if you have 100 pounds of

wood and the MC measures 10%, there is 10 pounds of water in the

wood. Or, just over 1 gallon. 20% MC is 20 pounds of water for each

100 lbs of wood (2.5 gallons).

Think about a house with 5000 pounds of wood. If all the wood was at

10% MC, there would 500 pounds of water (62 gallons) in the wood of

the house. But don't panic as 10% is very low except for desert-like

areas. Much of the country normally has as much as 14% (88 gallons).

Solid wood can handle that much water without growing mold or wood

rot. It can handle even more if it " comes and goes. " Kind of like

breathing. The problems start when the MC stays high for a long time.

Then surface mold can begin growing or internal mold begins to rot

the wood.

Manufacured wood like plywood, particle board and flake board (OSB)

are affected at lower MC and in less time than solid wood. One of

several reasons newer houses have more moisture and mold problems

than older ones.

One common error with moisture meters is the numbers on the meter are

true only for wood. The numbers will not be accurate for sheetrock,

for example, or particle board. But you can still compare dry

material with where you think there might be damp material. You just

won't know the actual MC.

The most common error, including for mold remediators, is beliving

that an area that measures dry does not have mold. Dry now does not

mean it has been dry forever. If wet in the past then there could

well be mold growth. (Remember, there will always be mold everywhere,

but not mold growth unless there has been dampness).

For more information, a short and simple FAQ can be found at:

_http://www.delmhorshttp://wwwhttp_ (http://www.delmhorst.com/faq.html)

Two other sites with good equipment but not much (non-techincal)

info:

_http://www.tramexlthttp://www.thttp_ (http://www.tramexltd.com/index.html)

_http://www.extech.http://www.extehttp://www.http://wwhttp://wwhttp_

(http://www.extech.com/instrument/categories/moisture/moisture.html)

An excellent, non-technical article by Burton of Dri-Eaz is

at: _http://www.dri-http://www.dri-http://www.dri-http_

(http://www.dri-eaz.com/RESOURCES/MaterialChar.html)

Mr Burton was directly involved in writing the drying section of the

recently released ANSI / IICRC S500 standard on water damage

restoration. Although the article focuses on the drying of materials,

he first explains how water can effect different materials such as

wood, sheetrock, tile, vinyl, etc. He also mentions the importance of

Categories of water.

Simply put, clean water from a pipe break is Category 1. You can

safely drink it. But once it touches something it can dissolve parts

of whatever it touches. This almost always makes it at least Category

2 water. It is " slightly contaminated " and will probably make you

sick if you drink it but it won't kill you because it isn't

infectious or otherwise deadly. Category 3 water has infectious,

toxic or other dangerous materials in it, like sewage. The importance

of Categories of water is that different materials affected by the

different Categories of water can just be dried, some can be

disinfected and dried, while others should only be removed and

replaced (Category 3, usually).

GE Protimeter has a book (fairly technical) at:

_http://www.gesensinhttp://www.gesehttp://wwhttp://wwhttp://www_

(http://www.gesensing.com/products/mini.htm?bc=bc_ge_protimeter)

BLD1700 - Dampness in Buildings $31.00

" The Protimeter book on dampness diagnosis, treatment and available

measurement techniques. The 'Dampness in Buildings' book explains the

nature of dampness in buildings, how to diagnose a dampness problem

as well as how to deal with the issue. It covers such areas as rising

damp, condensation, bridging and rainwater ingress and penetration.d

This is more than most of you want or need, but some of you may be

interested in the details. If you want to know even more, check out

infared cameras and the newest (pending) technique, radar, that can

actually detect mold growth rather than just moisture.

Finally, a new Web site has just been started by Ian Cull of Chelsea

Training that will have product reviews written by experts in the

industry rather than by the manufacturers. Not much there yet but you

may want to bookmark it at: www.IAQcomparisons.may

Carl Grimes

Healthy Habitats LLC

-----

> I haven't used these, but I was looking for one... The first one

> linked here (Extech), claims the deepest measurement depth (1.25

> inches). The third one (Tramex) is an analog meter. These three are

> in the $295- $349 range. How a meter needs to be held (in direct

> contact?), " aimed " and oriented when used, may limit its use in tight

> corners...

>

> Does anyone have experience with these, or similar moisture meters?

>

> _http://froogle.http://froohttp://frohttp://froogle.http://froo_

(http://froogle.google.com/froogle?q=Extech+Moisture+Meter+MO300)

> _http://froogle.http://froohttp://frohttp://froohttp://froogle.http:_

(http://froogle.google.com/froogle?q=Protimeter+Aquant+Moisture+Meter)

> _http://froogle.http://froohttp://frohttp://froogle.http://frohttp_

(http://froogle.google.com/froogle?q=Tramex+Moisture+Encounter+Plus)

>

> Bill

>

>

> At 10:34 AM 7/20/2006, _bobbinsbiomed@bobbins_

(mailto:bobbinsbiomed@...) wrote:

> >

> >A short while back the subject of electronic meters to measure for

> >moisture content in the walls was briefly brought up on this site

> >but did not really go anywhere. Has anyone been using any of these

> >instruments with any success to assist them in the identification of

> >the source of their illness?

> >

> >Does Carl or anyone knowledgeable in this area know if there are any

> >meters that are known to be accurate that can be purchased for under

> >$300, preferably around $150 or so. I would like to purchase one and

> >found many online, but I have no idea as to the quality of any

> >brand.

> >

> >