Well, 25% moisture is OK, even 30% will burn if you are out of dry wood. It will boil the water out and then burn. 20% is better and the 'goal' for many of us (my goal anyway). 12% is about as low as I can get and that is what most of the 2x4 and 4x4 non-treated salvaged construction wood is that I burn. For every 1% of moisture lost, you gain about 1% of heat value. Going from 30% to 20% is usually pretty easy. Below 20% gets harder and longer, especially for dense wood species. The species makes a difference, as does split size, tight or loose stacking, sun and wind exposure, temperature and average humidity. And of course how dry it is kept; you need to keep it off the ground and out of the rain, but open to air flow. Large barns or covered areas with open sides are better. You can also accelerate the process using greenhouses or stacking it in sheltered patios and the like. It is also better to stack the wood loose or alternate splits 90 degrees you will get better air flow and faster drying. Smaller splits dry faster as well.
OAK drying time.
- Thread starter clemsonfor
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Well, 25% moisture is OK, even 30% will burn if you are out of dry wood. It will boil the water out and then burn. 20% is better and the 'goal' for many of us (my goal anyway). 12% is about as low as I can get and that is what most of the 2x4 and 4x4 non-treated salvaged construction wood is that I burn. For every 1% of moisture lost, you gain about 1% of heat value. Going from 30% to 20% is usually pretty easy. Below 20% gets harder and longer, especially for dense wood species. The species makes a difference, as does split size, tight or loose stacking, sun and wind exposure, temperature and average humidity. And of course how dry it is kept; you need to keep it off the ground and out of the rain, but open to air flow. Large barns or covered areas with open sides are better. You can also accelerate the process using greenhouses or stacking it in sheltered patios and the like. It is also better to stack the wood loose or alternate splits 90 degrees you will get better air flow and faster drying. Smaller splits dry faster as well.
I'm certain drying time should be a bit different in SC vs MI or in New England simply because of the climate. I'll stick to 3 years or more for oak. I don't even mind waiting 6 or 7 years for the oak to dry. 
Well, if you have the time, wood resources and room to do it, great. Many of us do not. I have about a 10 cord firewood area limit myself, and I go though 3-4 cords a year. So I am on a 3 year rotation. Drying varies here greatly from year to year depending on the highly variable PNW temperature and 'moisture events'. Some years I burn wetter wood, some years dry wood.
Yes, I probe my wood a lot here with a MM.
The MM takes the mystery out of the process.A barn is the best, but I do not have one. A large and high 3 sides shed wood be good too, like my ex built last year at her place, but I do not have one of those either. I have mostly tarped 12 ft. by 4 ft. rows of wood on pallets on 3/4 minus gravel beds with t-posts on the ends. I have had to adapt those to the crappy weather in the last 4 years. I added heavy rolled asphalt under the pallets to keep ground moisture out of the lower wood in the racks. I also have two types of tarps; one top tarp to reflect sun and keep the rain off. Then I have larger tarps that I have under them to cover the top and sides in the rainy season. Problem with those is that they also trap moisture, but they are required to keep he rain out from the sides. I get a lot of high wind storms here, and a few feet of snow on average.
So now I am planning an open carport type structure with a concrete floor as I can build anything here that is under 200 sq. ft and lower than 10 ft. high w/o a permit. I would rotate in 4 cords of dry wood and that would be for that particular year.
red oak
Minister of Fire
When I open the door to the stove I can see the water coming out of the ends - it bubbles right out. If many pieces have the moisture you can hear it also.
Yeah, listen for the sizzle, sometimes its hard to see the water oozing out but you'll hear it.
StihlHead I can get some wood to 10-13% its called pine, that stuff in basically a year will hover around 11% for me, the oak, well im still waiting, like I said I have a stack in a shed that is going on 4+ years and last I checked it hovered around 15% and even with the correction chart that gives it at best 14%. Maybe another 2 years I can have that oak to 12%!!
As far as burn time in my cat stove there seems to not be much of a difference. Honestly there is a difference but not huge, I may get a few more hours of good coals out of the oak. BUT the real difference is in the heat output. There is a tremendous difference there. But burn time there is not much difference, but this could be due to the fact I burn the pine on warmer days and even with pine I have the stove drafted way down to reduce the heatoutput, where the oak is run on a slightly higher air setting for more heat.
There are exceptions to this as oak and pine species vary a lot in the western US, but typically oak is way better. 15% oak (Oregon white oak) will still give you about 60% more heat than 12% pine (Ponderosa pine) and burn just fine. Pine does not coal up either, whereas oak will coal up nicely which extends the heating time for me. The cost difference, as it were, is in space and time needed to dry the oak another year at least, and if you buy your wood, the oak will likely cost more money. I just went out and tested these woods in my stacks, both types were cut and split last year with the same drying location and storage conditions: the oak (Oregon white oak) is at 27% and the pine (Japanese black pine from my property) is now at 18%.
I do not understand the need or desire to get oak from 15% to 12% when all you are going to gain is 3% more heat? *shrug*
"I do not understand the need or desire to get oak from 15% to 12% when all you are going to gain is 3% more heat?"
No point it that what so ever, you have to do your own testing, some of things posted on here make no sense what so ever, my oak seems to get to about 17% and stays there no matter how long I leave it, and yes for you non believers that is 3 years. It does not take 3 years to dry Oak here either.
No point it that what so ever, you have to do your own testing, some of things posted on here make no sense what so ever, my oak seems to get to about 17% and stays there no matter how long I leave it, and yes for you non believers that is 3 years. It does not take 3 years to dry Oak here either.
Yes, I probe my wood a lot here with a MM.
A barn is the best, but I do not have one. A large and high 3 sides shed wood be good too, like my ex built last year at her place, but I do not have one of those either. I have mostly tarped 12 ft. by 4 ft. rows of wood on pallets on 3/4 minus gravel beds with t-posts on the ends. I have had to adapt those to the crappy weather in the last 4 years. I added heavy rolled asphalt under the pallets to keep ground moisture out of the lower wood in the racks. I also have two types of tarps; one top tarp to reflect sun and keep the rain off. Then I have larger tarps that I have under them to cover the top and sides in the rainy season. Problem with those is that they also trap moisture, but they are required to keep he rain out from the sides. I get a lot of high wind storms here, and a few feet of snow on average.
So now I am planning an open carport type structure with a concrete floor as I can build anything here that is under 200 sq. ft and lower than 10 ft. high w/o a permit. I would rotate in 4 cords of dry wood and that would be for that particular year.
Indeed having a barn is good....but not for drying the wood. It is still best to dry it outdoors. The 3 sided wood shed can work really nice too. We stack all our wood outdoors then in October we put enough in the barn to last through the winter.
As for covering the sides of the wood, I just never saw a need for it and most times it will do more harm than good. Let the air to it. As for rain, it won't soak into the wood hardly at all. Usually after a big rain, the wood can be dry within 24-48 hours. The only time wood is a sponge is if the wood is punky. Then for sure it will soak up lots of rain.
I took one split of Black Oak, 2 1/2 yrs old. One split of Red Oak that was 1 year old and one round of Red Oak that is 2.5 yrs old ( only Red Oak I had that old ) and measured the moisture in them.I tried to pick close to the same size. All exposed to the same drying process. Top covered with rubber in the sun and wind. I brought the wood inside for about 4 hours before splitting them. I used a cheap Harbor Freight meter.
The 2.5 yr old Black Oak came in at 12%, OH YEAH....The Red Oak round 2.5 yrs old averaged about 24%, guess because its a round. It was really all over the place. One end was about 20%, the other end which had a big knot on it was as high as 26%.. The 1 year old Red Oak came in at 23%.....
I'm sure I could get a better average by testing a few more of their brothers and sisters in the stacks, but, I just dont feel like it....
Note: Your results may vary .....
The 2.5 yr old Black Oak came in at 12%, OH YEAH....The Red Oak round 2.5 yrs old averaged about 24%, guess because its a round. It was really all over the place. One end was about 20%, the other end which had a big knot on it was as high as 26%.. The 1 year old Red Oak came in at 23%.....
I'm sure I could get a better average by testing a few more of their brothers and sisters in the stacks, but, I just dont feel like it....
Note: Your results may vary .....
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That 1 year red oak split is exactly what I got. The 2.5yr old red was definityl that high due to being round, and that's also why the one end was so low as well.
Honestly I don't see the point getting below 20-25% on a meter. If it happens great if not I'm ok with that. I keep 3-4 years worth of wood after that time it's getting burnt no matter what. We're building firewood not furniture!
I do think too dry hurts the combustion process. That can't happen with wood stored outside in my climate though.
Problem with that here of late: last year we set a record for consecutive days with rain with over 100 days. Last year we also set or tied records for rain in January, May, June, and October. I get on average 7-8 feet of precip here between October and July. My ex gets 10 ft. of precip average at her place by the coast! I got over a foot of rain last June, and over a foot in each month in Oct., Nov., Dec. and Jan this year. It let up this year in Feb-April with 'only' about a half foot each month. The wood gets wet and cold, and stays wet. A lot of my dry wood simply rotted last year here. This winter I made a wood storage caddy on my covered porch and moved wet wood there and used a box fan outside on 'warmer' days (above 40) to re-dry it. It was not a good solution. So I get the wood dry and fully tarp it when the rains come. That is the most common way to store it that I see around here. Another is to cover it with tin sheets.
Sorry. I see how that could have been mis interpreted. I meant "towards the end" , not the very end. Like 4 inches from the end. Still the inside of the wood.
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