Acceptable Moisture Levels

[jkeilson (James Keilson, CMI, Certified Master Inspector)]

Does anyone have a chart (or similar) that shows the
Acceptable Moisture Levels in different types of material, such as drywall, concrete, wood…ect. as a standard with a moisture meter.

Thanks in Advance:cool:

[rhensel (Russell Hensel)]

I would think these would fluctuate according to the weather conditions, where you live and how the house is lived in. There are too many variables to give an ‘estimate’ level.

Consider going to a place that you KNOW is dry and get a reading from there and then compare to other areas of the house with similar material.

Make sense?

[belliott (Bob Elliott, 450.0002662)]

I do it by comparison to surrounding area.
Make sense?

[jkeilson (James Keilson, CMI, Certified Master Inspector)]

Russell and Bob you both make perfect sense, thanks for taking the time to reply.

[jbushart (James H. Bushart)]

There are acceptable ranges that vary between different types of wood, as well. The charts that came with my moisture meter are helpful, but too extensive to post. Google the Delmorst BD-2100 and see if you can download the owner’s manual.

[belliott (Bob Elliott, 450.0002662)]

I use a pin type and as stated above material makes a difference and humidity levels.
Also matters how far or deep you poke it in.:)so get suspect area and then something close by (several ).
I never report exact percentage but do show the level on the screen while simply reporting the issue.
You poked for a reason and you can give your opinion on possible cause as long as you back it up with a corresponding issue or possible issue.At least that is how I do it.
Personally you should be careful where you poke that thing. It is like the guy who removes a few ceiling panels but not all .
Have a reason to suspect before using.

[bkelly2 (Brian Kelly, AZ Cert. # 60234)]

http://www.p1m.com/WM3.htm

http://www.fcs.uga.edu/pubs/current/B924.html

http://www.ecometrex.com/moisture_interpretation.htm

[belliott (Bob Elliott, 450.0002662)]

@bkelly2

http://www.p1m.com/WM3.htm

http://www.fcs.uga.edu/pubs/current/B924.html

http://www.ecometrex.com/moisture_interpretation.htm

OK so if the wood is 3% at the framing everywhere but where you see a stain and the stain area is 16% you consider it normal and move on ?:shock:

[rsmith24 (Robert Smith)]

You also have to consider what part of the country you live in. In New Mexico levels may be lower then what you would find in Washington state. Example a 5% reading in Washington may be considered normal while in New Mexico it may be considered high.

[mthomas2 (Michael D. Thomas)]

If you meter a variety of materials in your service area you will soon get as sense of the seasonal “norms”.

[kdolin (Kenneth Dolin, HI-59)]

of course all good answers, however in my area I typically base a fault on moisture content above 16 percent.

Below is from the Mold course.

Moisture Content

Moisture content (“MC”) is often expressed as a percentage (100 x (wet mass – dry mass)) ÷ (dry mass), or in terms of the amount of water in a certain volume (lbs./ft. cubed).

Mold requires moisture to survive, so protecting lumber and wood structures from moisture will help prevent mold growth. Mold growth can be limited if the MC of wood can be kept below 20%. An MC below 17% means that virtually no microbial growth will occur on even the most susceptible materials. Southern pine dimensional lumber is typically kiln-dried to a maximum 19% MC or less. The moisture content is indicated on the grade stamp. Moisture content is related directly to particular substrates or materials. Microbial growth is limited when the MC of gypsum board is below 0.6%, when brick is below 0.8%, when wallpaper is below 10.5%, and when concrete is below 5%. One study showed that a moisture content greater than 5% permitted the growth of Penicillium glabrum and Aspergillus versicolor on ceiling tiles in a laboratory.

[belliott (Bob Elliott, 450.0002662)]

@kdolin

of course all good answers, however in my area I typically base a fault on moisture content above 16 percent.

Below is from the Mold course.

Moisture Content

Moisture content (“MC”) is often expressed as a percentage (100 x (wet mass – dry mass)) ÷ (dry mass), or in terms of the amount of water in a certain volume (lbs./ft. cubed).

Mold requires moisture to survive, so protecting lumber and wood structures from moisture will help prevent mold growth. Mold growth can be limited if the MC of wood can be kept below 20%. An MC below 17% means that virtually no microbial growth will occur on even the most susceptible materials. Southern pine dimensional lumber is typically kiln-dried to a maximum 19% MC or less. The moisture content is indicated on the grade stamp. Moisture content is related directly to particular substrates or materials. Microbial growth is limited when the MC of gypsum board is below 0.6%, when brick is below 0.8%, when wallpaper is below 10.5%, and when concrete is below 5%. One study showed that a moisture content greater than 5% permitted the growth of Penicillium glabrum and Aspergillus versicolor on ceiling tiles in a laboratory.

All true though not sure if you 100% understood (or me ) that as used in the field.
Guess it depends if you are being a mold scientist or simply looking for water Intrusion which I think most of us are.

The above talks of laboratory conditions and does not explain much about 1 day after rain vs several days after a rain.:).I will stick to comparisons.

[jbraun (James E. Braun, CMI)]

IICRC says Normal wood moisture is below 16%.

[jbraun (James E. Braun, CMI)]

@belliott

I use a pin type and as stated above material makes a difference and humidity levels.
Also matters how far or deep you poke it in.:)so get suspect area and then something close by (several ).
I never report exact percentage but do show the level on the screen while simply reporting the issue.
You poked for a reason and you can give your opinion on possible cause as long as you back it up with a corresponding issue or possible issue.At least that is how I do it.
Personally you should be careful where you poke that thing. It is like the guy who removes a few ceiling panels but not all .
Have a reason to suspect before using.

This is the main reason why I use Protometers because of the green, yellow and red scale. If it every goes to a court, I do not have to answer the stupid question of when did you have your moisture meter calibrated?

[ryoung7 (ROBERT YOUNG, CMI)]

@belliott

I use a pin type and as stated above material makes a difference and humidity levels.
Also matters how far or deep you poke it in.:)so get suspect area and then something close by (several ).
I never report exact percentage but do show the level on the screen while simply reporting the issue.
You poked for a reason and you can give your opinion on possible cause as long as you back it up with a corresponding issue or possible issue.At least that is how I do it.
Personally you should be careful where you poke that thing. It is like the guy who removes a few ceiling panels but not all .
Have a reason to suspect before using.

Thanks BOB
I was looking for some information on moisture and how I will define my observation.
You seem to have a very good and pro-quo standard in place that does not need to be improved upon.
Thanks.
Is that picture of you after a wild night out or did you just win the lottery?

[Rodney_Allman]

Sometimes the answers are not definitive even though our clients push for definitive reports regarding what is an acceptable level. So much gray area…

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