Moisture meters

[Guest guest]

, 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.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.delmhorst.com/faq.html

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

info:

http://www.tramexltd.com/index.html

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

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

at: 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.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. "

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.com

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.google.com/froogle?q=Extech+Moisture+Meter+MO300

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

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

>

> Bill

>

>

> At 10:34 AM 7/20/2006, 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.

> >

> >

[Guest guest]

I have a drop ceiling over my kitchen and in that

drop ceiling in plumbing of upstairs bathroom.

I've often wondered about how plumbing is up

there. It was opened up once about 1991 to do

some repair of 'something', can't remember. I

wish now I had had whole area opened up and

examined everything, the plumbing is so old and

leak could easily happen from house settling and

age, etc. Instead we just fixed the one thing,

and replastered the ceiling. Well, I think it

was replastered. Maybe they put drywall up

there. I don't see any seems. Reason I wonder

is because I have a hard time keeping the ceiling

of kitchen painted. The paint peels off. It

never looks damp. I don't know that tested the

moisture an inch or so would help. Maybe an

infrared camera? At a time like this, we could

use the x-ray vision of Super Man, right?

--- " Carl E. Grimes " <grimes@...> wrote:

>

> 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.

>

>

[Guest guest]

Would using pin type of plaster walls create problem, encourage a

crack, etc, to you know?

--- In , " Carl E. Grimes " <grimes@...>

wrote:

>

> , 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.

>

[Guest guest]

That's probably really inexpensive. The ones professionals are much more

expensive. I wonder how well that one works, and if there is a quick, easy way

to determine that.

Ella

>

> Has anyone bought a reasonably priced moisture meter they can recommend. I

was looking at Amazon.com at these and there is one at Sears that isn't too

much. The one at Sears is about 50.00 which I was hoping not to go above that

price:

>

> http://tinyurl.com/yb6mlnm

>

> http://tinyurl.com/yzus9pr

>

[Guest guest]

I just googled " how does a moisture meter work? " amd got several sites.

http://www.hreporters.com/CatalogCart/delmhorst_faqs.html

HOW DOES A MOISTURE METER WORK?

There are two types of moisture meters typically used by the home inspector.

Pin-Type meters, which utilize the principle of electrical resistance, use wood

or other hydroscopic materials as an element in a circuit by driving two pins or

electrodes into it.

Pin-less meters like the Accuscan uses radio frequency signals to penetrate the

material being tested. There is no pin intrusion into the surface of the

material you are checking.

Ella

>

>

> From: barb b w <barb1283@...>

> Subject: [] moisture meters

>

> Date: Wednesday, December 30, 2009, 11:42 AM

>

>

> Has anyone bought a reasonably priced moisture meter they can recommend. I was

looking at Amazon.com at these and there is one at Sears that isn't too much.

The one at Sears is about 50.00 which I was hoping not to go above that price:

>

> http://tinyurl. com/yb6mlnm

>

> http://tinyurl. com/yzus9pr

>

[Guest guest]

B.,

I had asked about this a few years back, so here's what I recall from a real lay

perspective.

A Certified Industrial Hygenist would have a moisture meter and they can use it

to read moisture levels in a room and also inside the walls through electric

sockets and by also making small hole in a wall.

 

From what I recall, a good moisture meter might be costly. But you can get a

combination thermostat and humidistat at hardware store. We have one for about

$30 that measures the temp and humidity in a room and will also have the temp

and humidity readings for outside. It seems accurate enough for home use, but

wouldn't rely on it for an official reading of moisture or humidity.

Sam

What does a moisture meter do?  

on-text portions of this message have been removed]

[Guest guest]

Ella and others,

The info on moisture meters you provided is accurate but needs

a little explanation so people don't get the wrong impression

about what they can and cannot do.

Regardless of the type, they measure moisture content in a

material as a percentage of weight. A 20% reading in wood, for

example, means 20% of the total weight of the wood is from the

water. So if you have 100 pounds of wood then there is 20 lbs of

water in it. That's 2 1/2 gallons, a lot of water. If a house has

2000 pounds of wood and it is all at 20%, then there is 200 lbs of

water, or 25 gallons. That's a LOT of water! Imagine what

happens to the humidity inside if that were to evaporate? And

condense on cool surfaces, including inside the walls.

However, solid wood can generally handle that without rotting.

Plywood less and OSB/particle board much less. This is one

reason why newer houses get more mold more easily than old

houses.

Moisture meters are calibrated for wood but the absolute

measures will differ by species of tree. They will not be accurate

for drywall or other materials.

However, they can be used for comparative measurements.

Obtain a reading from a location and material you know is dry.

Then measure a location of the same material you think might be

wet. If it is higher then it has more moisture. You don't know how

much but you do know it is slightly more or hugely more wet. This

is important information but, as with settling plates for mold, is not

proof without other information so a correct interpretation can be

made.

For example, metal will trigger high readings. So you have to map

the pattern of readings to see if it is a line across the wall from

electrical wiring, for example. Or reinforcement on a curved

corner of a wall. Or the bottom 1/2 inch of shower tile because

the tub has a lip that high behind the tile. Or the pipe bringing

water to the tub/shower head.

Moisture meters only measure the conditions at the time of

measurements. A dry reading says nothing about the past. So a

wall could have been wet in the past and grown tons of mold but

the moisture meters will " find " nothing when the wall is dry. Also,

despite what some contractors and consultants believe, moisture

meters don't detect mold. And being dry now doesn't mean there

is no mold from past water.

Pin-type meter can only measure as deep as the pins go. Non-

penetrating meters are limited to 1/2 or 3/4 inch depending on the

meter and the material being measured. They cannot determine

the condition of an attic, crawlspace, or wall on the other side of

the framing.

An inexpensive meter such as the Sears model won't be as

accurate or as durable as the $300 to $3000 meters

professionals use. But for occasional comparative measurements

is can be a great tool for checking conditions.

As with everything else there is a lot more detail and room for

error and misinterpretation, but these are the basics.

One last comment. Moisture meters measure materials, not the

air. The description for measuring humidity is for a hygrometer,

not a moisture meter. Also, checking the interior of a wall by an

electrical outlet or through a small hole will provide a very rough

indicator of humidity inside the wall but I wouldn't rely on it and it

doesn't measure moisture content of the drywall or framing.

Any consultant or contractor, regardless of their certification,

should have a moisture meter as a required tool. However, many

of those with the " higher " or more " scientific " certifications have

never had training in moisture meters, infrared cameras (another

way of the checking for moisture), the biology of mold, or building

science. And absolutely none include information about people

occupying the building and how to evaluate conditions and make

recommendations based on their needs.

Actually, there is one. It is the Healthy Home Specialist (HHS)

from the National Center for Healthy Homes training center at

http://www.nchh.org/Training/National-Healthy-Homes-Training-

Center.aspx

Info on the HHS is at: http://www.nchh.org/Training/Healthy-

Homes-Specialist-Credential.aspx

You can download their free course materials from:

http://www.healthyhomestraining.org/Practitioner/index.htm

Carl Grimes, HHS CIEC

Healthy Habitats LLC

-----

I just googled " how does a moisture meter work? " amd got several sites.

http://www.hreporte rs.com/CatalogCart/delmhorst_faqs.html

HOW DOES A MOISTURE METER WORK?

There are two types of moisture meters typically used by the home inspector.

Pin-Type meters, which utilize the principle of electrical resistance, use wood

or other hydroscopic materials as an element in a circuit by driving two pins or

electrodes into it.

Pin-less meters like the Accuscan uses radio frequency signals to penetrate the

material being tested. There is no pin intrusion into the surface of the

material you are checking.

Ella

>

>

> From: barb b w <barb1283@...>

> Subject: [] moisture meters

> groups (DOT) com

> Date: Wednesday, December 30, 2009, 11:42 AM

>

>

> Has anyone bought a reasonably priced moisture meter they can recommend. I was

looking at Amazon.com at these and there is one at Sears that isn't too much.

The one at Sears is about 50.00 which I was hoping not to go above that price:

>

> http://tinyurl. com/yb6mlnm

>

> http://tinyurl. com/yzus9pr

>

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[Guest guest]

Moisture meter:

You can press the pin of the meter up against a wall to see if wall has extra

moisture there, to see if there may be leak inside of wall or inside of ceiling

but only can judge if moisture is high in material you press it up against. I

would not need it for room humidity. You can get a good room humidity gauge for

15 bucks.