Time frame for drying interior trim.

[Sea Saw]

Hello, I am a newbie to this forum, actually today is the first day I have posted.  I have been reading for the last couple of months and enjoy all the information.  So the question?  I have milled a bunch of white pine and pitch pine for the house that I am building.  The sheet rockers are finishing this week.  I have some boards air drying since early April and I am planing to cut some more this week.  What is the best amount of time to dry these two types of wood before using them for interior trim boards.  I have milled all the boards a little bit bigger than needed to acount for plaining and routering them.  Any help would be appreciated and thank you. 8)

[Ianab]

Hi Sea Saw

Welcome to the forum.

Best idea is to get a moisture meter, then you will be sure. Ideal moisture content depends on your local envorinment, but you probably want the wood below 10% before you use it.
The good news is that pine dries pretty fast.
For 1" boards, 3 months outside in warm weather should have it down around 15%, then bring it inside and put some fans on the stack for a few more weeks and it should be getting close. You do need to make sure it's properly dry though, or it's going to move and shrink a bit too much once in place.
The old rule of thumb is 1 year per inch of thickness, but thats a worst case thing, like oak sawn in the late autumn might not be dry till next autumn. But warm weather and a faster drying wood will take a lot less time.

Cheers

Ian

[Brad_S.]

Welcome to the Forestry Forum.

I would echo Ianab on everything but, IMO, I don't know if stacking it inside will help much as the indoor and outdoor RH this time of year is the same, only artificial heat or perhaps a dehumidifier in a sealed room will remove much more moisture. If you're using butt joints or copes, 15% may not be bad, but if you're using miters, you may see them separate during the first winter heating season. I would like to see you send them through a kiln not only to get the moisture content down, but also to set the pitch so your trim isn't weeping into your finish or gumming up your cutters. It's not the end of the world if you just use air dried though.

[Sea Saw]

Thank you for the responses.  I live on an island and to my nkowledge the only kiln is a solar one a guy made to speed up the drying of his firewood.  I will have to go with the air dry method.  Thanks again.

[bman]

If I may expand this I have a question regarding MC and RH. If you get the wood to 8% MC and then move to your project site and the RH is higher at the project site than the enviroment the wood was dryed at will the wood regain a higher MC above the 8-10%? thanks bman

[Ianab]

will the wood regain a higher MC above the 8-10%?

Yes

The wood will absord moisture from the air untill it's at equlibrium again. It will usually go up and down with the seasons, hence you get expansion / contraction in furniture.
When kiln dried hardwoods from the US are imported into NZ they actually have to be restickered and left to GAIN moisture before they are used,  :

Cheers

Ian

[bman]

I guess my question then is; What is a typical MC for wood flooring once installed? Winter MC, Summer MC, MC for an installation in the Pacific NW? If the ideal is to KD to 6-8% before install does the flooring ever regain a MC say above 10% once installed and finished? I'm sure there are variables to my question but most homes are heated to about the same temp. 

[bman]

I borrowed a probe type MC meter  today and checked my stack of flooring planks that are drying in preperation for installation in the new house; 15%-16% MC. Checked areas of the timber frame and 2x6 stud wall envelope of new house;14%-16% MC Checked a few pieces of known green lumber; about 26% MC. Took the meter in the house I now occupy and checked the underside of the coffee table, inside of dresser drawer fronts, pantry shelving etc, all metered out at 11%-11.5% MC
Why the he!! do I need to dry this flooring to anything less than 10% before I install it? ???

[Ianab]

Sounds like your climate is pretty similar to ours.  :D

You aren't going to get the wood under 10%, and you dont want to either. If you do, it will just regain water to something like whats in your house now.
Your 15% is getting close to dry, and you probably need it inside to get it any dryer. Maybe close it up in a room with fans and a portable dehumidifier will help. The closer you can get it to the 11.5, the better, but you will probably end up having to use it around 13-14%. Not perfect, but close enough in your climate.
In other areas away from the coast it gets very dry in winter when houses are centrally heated and humidity is naturally low. That probably accounts for 95% of the US population? This is where the 8% figure comes in, we call anything under 14% dry here  ;)

Cheers

Ian

[bman]

Thaks Ianab I feel better now. I got all the planks in the house now (took me and my kid daughter 5 hrs to  move em all last weekend!) but there stacked and stickered with fans and the woodstove going. Ill check em dailey and give a report next week. ;)

[bman]

After about a week of drying my flooring inside with fans and woodstove going I have managed about a 1% drop in MC. The past week was somewhat cloudy and mild with daytime RH only coming down to mid 50's. This week weather is much warmer (mid to upper 70's) with sun and daytime RH down to about 40% with a nice breeze.  Now that I am done painting the exterior I will throw the doors and windows open during the day.  Will report again next week. Bman

[Don_Lewis]

Depends on whether you have a cold winter where you are. If you are on an island in Maine, you will find most of your lumber to be around 10-12% this time of year but in heating season, it will be around 6%. So if you want tight joints in the winter, you should dry it lower. Pine has a lot of pitch and using it without heating to well above what it will see in the house to set pitch, is a mistake, I think.  Wood that the sun shines on or near a heater will get warm and not look that great. But Pine goes through a molder best at 8-12%.

[bman]

Thanks Don. Our winter climate is fairly mild with lots of rain. The weather here is calling for highs in the 80's and 90's for the next week with a good breeze and low humidity so that should realy help to dry the planks further. I,ve got some checking going on now and my observations for this wood type tells me Im getting close. Will see what the moisture meter says after about a week of hot weather. bman