Moisture content and readings

[Rob Holcomb]

Recently I purchased a Delmhorst J-Lite moisture meter (New) and went around my shop today and checked the moisture content of all of my rough cut wood. Everything reads 11%. I have Wood I know was kiln dried to 6% that I purchased from a local mill, I have stickered lumber that has been in my shop about 7 months and old pieces of 2X4's I had laying around my shop. I checked it all in various locations on the boards and everything is 11%. I am assuming that 11% is the best I can do in my shop and all the wood is ready for use. Then I went in my house and checked the moisture content of old framework that has been there since the 1860's and it reads 9%. I also checked framework that has been in place for about 10 years and it too read 9%. Since bringing rough lumber into my house to acclimate to 9% before working on it isn't an option for me unless it's something small I plan on making and it would likely re-acclimate to 11% by the time I was done working with it, how much trouble do you think I will get into if I build furniture pieces, cabinets etc. for my house using lumber at 11% and then once in my house they go to 9% Will there be much movement with a decrease of 2% Should I expect cracking, splitting, warping, cupping etc.? As a side note, I live in Western NY where over the past week we have had sunny skies and 65 degrees, a couple days of rain and temps in the 50's, a day of snow where the temp barely hit 40 and today it's sunny and 50 degrees so the weather is all over the place this time of year.

[David Kumm]

I'm in Wisconsin and have never had a problem if I start out in the 10-12 range. 2% is pretty close. If you throw some heat in the shop I bet you get down some more. Dave

[John TenEyck]

A 2% difference will make no difference, IMO. If you have not had problems in the past you aren't likely to in the future, even though you now know the moisture content is different. That being said, I personally don't like using lumber at 11% (I live in WNY also.) so I run a dehumidifier in my shop to keep the humidity around 50% (9% MC) year round.

Your moisture meter is your best friend when you go to buy wood. Quite surprising sometimes to see how high the MC can be in KD wood.


John

[Bill Davis]

"Moisture content and readings
Recently I purchased a Delmhorst J-Lite moisture meter (New) and went around my shop today and checked the moisture content of all of my rough cut wood. Everything reads 11%. I have Wood I know was kiln dried to 6% that I purchased from a local mill, I have stickered lumber that has been in my shop about 7 months and old pieces of 2X4's I had laying around my shop. I checked it all in various locations on the boards and everything is 11%. I am assuming that 11% is the best I can do in my shop and all the wood is ready for use. Then I went in my house and checked the moisture content of old framework that has been there since the 1860's and it reads 9%. I also checked framework that has been in place for about 10 years and it too read 9%. Since bringing rough lumber into my house to acclimate to 9% before working on it isn't an option for me unless it's something small I plan on making and it would likely re-acclimate to 11% by the time I was done working with it, how much trouble do you think I will get into if I build furniture pieces, cabinets etc. for my house using lumber at 11% and then once in my house they go to 9% Will there be much movement with a decrease of 2% Should I expect cracking, splitting, warping, cupping etc.? As a side note, I live in Western NY where over the past week we have had sunny skies and 65 degrees, a couple days of rain and temps in the 50's, a day of snow where the temp barely hit 40 and today it's sunny and 50 degrees so the weather is all over the place this time of year. "

I have Wood I know was kiln dried to 6%
Once 6% doesn't mean always 6% since wood is hygroscpopic. At least you have an idea what it was suppose to be at one time. It will vary in MC based on the surrounding relative humidity. Do you know what the average RH in your shop and house is? One of the best accessories to a moisture meter is a %RH meter. RH and MC go hand in hand. If your MC measurement is accurate, 11% MC figures to an equilibrium RH of 60% in your shop and 9% maybe about 50% in the house.

I am assuming that 11% is the best I can do in my shop
To dry it further in your shop you can either dehumidify the shop or heat the shop. Heating the air in your shop will drop the RH unless you let more humid air in.

Will there be much movement with a decrease of 2% Should I expect cracking, splitting, warping, cupping etc.?
Yes there will be movement with a 2% change. Most cracking, splitting, warping and cupping occur when the wood is dried from the green state (wet) to about 20%MC. So likely most of that has already been done if it is going to be. However there are circumstances that could cause some of that to still show up. If it is not degraded now most of the likelyhood of it happening with a 2% or so change is minimum. But it will shrink a bit with a 2%MC change. How much depends on the wood specie, grain direction and finish. Whether that in fact creates a problem depends on the project design i.e. how pieces are fitted together.

It will probably be OK but would I guarantee it? Nope! Too many variables. Best guarantee is know the MC and RH and how moisture affects your specie of wood.