# How to measure moisture ?



## skpatel76 (Mar 3, 2009)

Hi I am totally new in this field, i am buying house. i bought Mastercraft moisture meter to measure moisture in house i want to buy. can somebody give me measurement chart what is good and bad results. 
i measure wall it was showing 15%. Is it bad means a lot moisture or its ordinary ?
thanks 
hope to get helped.
shailesh


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## Loose (Mar 2, 2009)

Measuring moisture in a house by someone new to a handheld meter and performing a reasonable analysis is really tricky business. But in general, the wood should arrive on site from a supplier at anywhere between 8-15% M.C. You didn't say if it was a newly constructed home or an existing house, whether or not it has been heated, but unless it was constructed during this last fall / winter, the M.C. of the wood should have dried out to somewhere between 6-10%. That being said, the M.C. will vary, but 15% is on the high side

First, I'd check the callibration of you meter. Assuming its a probe type, make sure you are getting full imbedment. The best recommendation I can make is either contact an experienced home inspector or an architect that has building envelope experience in order to get someone with a background in moisture mitigation to give you a hand.

Loose, A.I.A.


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## Hamlin (Dec 25, 2005)

Hi,

I suggest you contact the pros, like, insulators or contractors. They can give you the correct info that you're after. I do agree, 15% sounds a little high.


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## dovetail_65 (Jan 22, 2008)

skpatel76 said:


> Hi I am totally new in this field, i am buying house. i bought Mastercraft moisture meter to measure moisture in house i want to buy. can somebody give me measurement chart what is good and bad results.
> i measure wall it was showing 15%. Is it bad means a lot moisture or its ordinary ?
> thanks
> hope to get helped.
> shailesh


Actually if we are talking framing lumber even 19% is acceptable. The norm is 15%.

The lower rating for hardwoods(trim etc) are max 10% - 12% and for furniture the wood should be 6 - 9 %.

According to the USDA’s Forest Products Laboratory, "Softwood lumber intended for framing in construction is usually targeted for drying to an average moisture content of 15%, not to exceed 19%. However, softwood lumber for many other uses is dried to a low moisture content, 10% to 12% for many appearance grades to as low as 7% to 9% for furniture, cabinets, and millwork. Hardwood lumber for framing in construction, although not in common use, should also be dried to an average moisture content of 15%, not to exceed 19%. Hardwood lumber for furniture, cabinets, and millwork is usually dried to 6% to 8% moisture content." 

http://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr113/ch12.pdf

Moisture within a wall cavity is a totally different thing though. If you are just testing the drywall and it is 15% there is water getting behind the wall.


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## dovetail_65 (Jan 22, 2008)

skpatel76 said:


> Hi I am totally new in this field, i am buying house. i bought Mastercraft moisture meter to measure moisture in house i want to buy. can somebody give me measurement chart what is good and bad results.
> i measure wall it was showing 15%. Is it bad means a lot moisture or its ordinary ?
> thanks
> hope to get helped.
> shailesh


Actually if we are talking framing lumber even 19% is acceptable. The norm is 15%.

The lower rating for hardwoods(trim etc) are max 10% - 12% and for furniture the wood should be 6-8%.

According to the USDA’s Forest Products Laboratory, "Softwood lumber intended for framing in construction is usually targeted for drying to an average moisture content of 15%, not to exceed 19%. However, softwood lumber for many other uses is dried to a low moisture content, 10% to 12% for many appearance grades to as low as 7% to 9% for furniture, cabinets, and millwork. Hardwood lumber for framing in construction, although not in common use, should also be dried to an average moisture content of 15%, not to exceed 19%. Hardwood lumber for furniture, cabinets, and millwork is usually dried to 6% to 8% moisture content." 

http://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr113/ch12.pdf

But moisture nothing a wall cavity is a totally different thing. If you are just testing the drywall and it is 15% there is water getting behind the wall cavity. If you are in a stud 15% is fine. If you have 15% moisture in the wall cavity I suspect you would smell mold upon closer inspection. There are so many different things to measure I would read up a bunch. In my experience even many pros do not know nearly as much about moisture and how to stop, control and eliminate it as they should. Start with the link I posted above. Where you live makes a HUGE difference to what levels are acceptable.


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