Size (Thickness) of Firewood

Joos_15

New Member
Jun 10, 2015
3
Nova Scotia
Hello all:

I'm new to the forum, and have looked at many posts (enjoying them greatly), but haven't found one to answer my question. My apologies if I've missed it, and in that case perhaps you could direct me to the relevant post.

I have three wood stoves:
Osburn 1600 (1.85 cubic foot firebox)
Jotul F100 (Small-medium size)
Jotul F602 (small)

My question is about wood size: Is there a way to determine optimum wood thickness size for a stove? Is there such a thing as wood that, even though it fits in the stove, is too big to burn efficiently? I'm assuming that my practice of mixing large and small pieces in a burn is the best way to use the stoves. But is there such thing as wood that should be split before burning, even though it fits in the stove?

I ask this because I have a new supplier this year, and the wood is much larger (thicker) than I've used in the past. I want to be able to use the wood as efficiently as possible. He has delivered a good mix of large and smaller splits, but I'm wondering if the large pieces might need to be split again? The largest pieces seem to be about 12 inches across.

I would greatly appreciate your thoughts, and apologies for the novice-stye question!

-J
 

davo

Member
Apr 24, 2015
131
CT
Great question. I am wondering this also. For my stove, I use the large pieces for overnight and I get longer burn times out of them. I do have smaller splits and I load the stove up with them but I do not get the same burn times. With the larger splits, I am able to fit one or two at the bottom, then fill in the rest with the smaller ones and am able to get 8-10 hour burns. Hope this helps!
 

Grisu

Minister of Fire
Nov 1, 2010
4,121
Chittenden, VT
The question is if those thick splits dry well enough to get them below 20% internal moisture. When you just got those 12" splits those may take years to dry out depending on the species. Did you ever split some of them and tested the center of the fresh surface with a moisture meter?
 

begreen

Mooderator
Staff member
Nov 18, 2005
78,033
South Puget Sound, WA
A 12" split is huge. That would be too large for our big stove. Your supplier got lazy and should be called on it. To have a good variety of firewood sizes for the stoves you mentioned I would want the splits to be in the 3-6" range.
 

Highbeam

Minister of Fire
Dec 28, 2006
16,098
Mt. Rainier Foothills, WA
Yes, 12" is enormous. Can you even load those into your stove? Can you grip it by the end with one hand and hold it horizontal as you would when you load?

My "big" splits end up being 6" across the longest dimension. All can be picked with one hand. It's nice to have a mix of split sizes but I have found that 3-6" splits (again the longest edge) are a good mix. You can always resplit them as you burn them if you need some more small ones.
 

msjones2452

New Member
Feb 23, 2015
74
Denver CO
I'm not sure this will actually answer your question but I'll give my two cents anyway. I think wood size is somewhat dependant on your stove and what your looking to achieve. For example, I have a Hampton HI400 insert which is a so called "hybrid" wood burner utilizing a secondary burn tube and a catalyst. If I am looking for "quick" heat and shorter burn times, I do a partial load of smaller splits of softer woods. This tends to burn fairly quickly producing high heat sooner but for a much shorter duration. On the other hand, if I'm wanting to keep the house warm all day/night with little to no temp. fluctuations, I will load as many larger splits as I can fit and fill in with smaller stuff to fill the firebox as full as possible. I try to use hardwoods when burning all day/night but I am not overly picky about that. I don't notice a lot of difference in overall warmth between hard/soft woods but there is a significant difference in burn times. (avg. 12 or so hrs. full load soft/easily 14+ hrs. hard)

For my particular insert, I tend to see longer/more consistant heating using bigger splits BUT my goal when looking for all day/night heat is to pack as much wood into the hole as I can fit. I'm sure results will vary depending on the type of stove i.e. seconday burn/catalytic/hybrid. I'm even willing to bet that two of the exact same stoves will vary depending on a multitude of factors.
 
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notshubby

Member
Mar 26, 2015
139
constantia ny
this year I split everything about 6 inch round in half. 8 inch I did thirds. 10 inch or so I quartered. and the real big ones I shot for maybe 6 to 8 inches across at widest point unless they were real flat then I let them run over a bit. figuring the stuff that came from real big rounds had no bark on at least 3 if not all sides. mostly all maple cherry and ash. I just picked up about a full cord of small stuff cause it was free with most of it being around 3 to 4 inch diameter on the big end. im hoping will dry out enough cause its so small to mix in this winter. but like I said this is my first year with the Englander inside so its all experimenting this year. I have about 8 full cord so far so hopefully ill have a good amount left over for next winter although though that number may be higher by the time winter gets here.
 

Joos_15

New Member
Jun 10, 2015
3
Nova Scotia
Many thanks to all for your time in answering my question. So to summarize your collective advice, I'm assuming (given the 3 stoves I have) that I want to have a good mix of large and small splits, but that the largest ones (12-inch, e.g.) are too big and should be re-split.

Very pleased to have found this forum. This will be our 5th winter heating exclusively with wood, but I still feel like a novice. Your answers are very helpful!
-J
 

begreen

Mooderator
Staff member
Nov 18, 2005
78,033
South Puget Sound, WA
You might want to start resplitting the thickest splits right away so that they can dry out better. 12" thick wood is going to season very slowly.
 

Woody Stover

Minister of Fire
Dec 25, 2010
10,476
Southern IN
I don't need big splits to get good burn time, since I can cut the air pretty low on my cat stove. I generally mix it up at 3-6". Smaller splits get burning quicker on a cold start, or a low coal bed, but I also have kindling of Pine or Poplar for that as well.
 
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begreen

Mooderator
Staff member
Nov 18, 2005
78,033
South Puget Sound, WA
No cats in their list of stoves. The F602 and F100 are going to want smaller splits. The Osburn can handle the 6 inchers.
 

glennm

Burning Hunk
Dec 26, 2010
192
S Ontario
FWIW, I have an electric splitter in my garage and I use it daily to adjust split size. I find it invaluable!
 
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kennyp2339

Minister of Fire
Feb 16, 2014
4,386
07462
I use to cut my pieces up to an average 4" diameter, I started making larger pieces like 6 -9" diameters, mainly because I'm a few years ahead and the wood can dry out, the larger pieces I feel burn longer / with good heat. If you go on youtube and type Blazeking woodstoves there's a video showing one of the BK guys talking about there product while taking splits from the pile, take notice how big there splits are, that's what I am aiming for now.
 
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tarzan

Minister of Fire
Jan 16, 2014
1,545
wv
When I helped my dad with his firewood he would always remind me to "split a few all nighters." This meant a few occasional large/huge splits for his smoke dragon.

Now, with more modern and generally smaller stoves I find splits in the 4" to 6" range most versatile.
 

Highbeam

Minister of Fire
Dec 28, 2006
16,098
Mt. Rainier Foothills, WA
If you go on youtube and type Blazeking woodstoves there's a video showing one of the BK guys talking about there product while taking splits from the pile, take notice how big there splits are, that's what I am aiming for now.
Like BG said earlier, we cat guys play by different rules. The OP has non-cats that aren't as able to take advantage of a smoldering pile of big logs.

I watched that BK video and tried those large splits one year. Well, it didn't work as well as I would have thought since we cat guys are able to stuff our stoves tight and full I found that I needed smaller splits to fill the firebox tight. Also, with big splits it takes longer to get the stove up to cat engagement temp. If you are short sheeting your burns (12 hour cycles vs. 24 with partial loads) and able to keep the stove up to temp then I suspect that you can make better use of big splits in a cat stove.
 

begreen

Mooderator
Staff member
Nov 18, 2005
78,033
South Puget Sound, WA
This also depends on the wood species. Big splits work well in the T6, just not 12 inchers! I like to burn 8" spits of doug fir. The wood's high oil content make small splits go up too quickly, especially when well seasoned. But for locust and madrona I typically burn 6" splits.
 

kennyp2339

Minister of Fire
Feb 16, 2014
4,386
07462
Stove size, stove type, wood dryness, wood type, actual climate and comfort zone all have something to do with split size. If you have a small fire box obviously your not going to have huge splits, stove type - epa, smoke dragon, cat stoves all have different tolerances. Wood type & dryness - figure a large 8" thick split of larch will dry out and be ready a lot faster than white oak (wood density) Climate type - living in NNJ I may need larger splits during the heart of winter vs someone living in Georgia. Comfort - I'm young I can carry large splits all over the place, my mom up the road is now 62 and she may not be as comfortable moving the same size pieces all the time
 

blades

Minister of Fire
Nov 23, 2008
3,272
WI, Leroy
Only problem with discs is stacking to get them dry unless you alternate with conventional splits. I cut a lot of limbs on the band saw 4" on down split down the middle those smooth cuts stacked together do not allow air passage so need to be mixed around. The smooth cuts even on a sq allow for really tight loads in the stove with minimal ignition all over for longer burn times ( kinda like what is recommended for using compressed blocks - stack in stove tightly to minimize surface area of ignition.) boy my fingers are haveing a t & y problem this morning on the key board.
 

Ram 1500 with an axe...

Minister of Fire
Mar 26, 2013
2,327
New Jersey
Any pics?
 

begreen

Mooderator
Staff member
Nov 18, 2005
78,033
South Puget Sound, WA
Very nice. That's a pretty fancy way to stack cord wood. >>
 

husky345 vermont resolute

Feeling the Heat
Sep 20, 2012
393
london, ontario
Only problem with discs is stacking to get them dry unless you alternate with conventional splits. I cut a lot of limbs on the band saw 4" on down split down the middle those smooth cuts stacked together do not allow air passage so need to be mixed around. The smooth cuts even on a sq allow for really tight loads in the stove with minimal ignition all over for longer burn times ( kinda like what is recommended for using compressed blocks - stack in stove tightly to minimize surface area of ignition.) boy my fingers are haveing a t & y problem this morning on the key board.
sorry what I meant is that ill just set a disc or two on a nice bed of coals once in awhile for something different lol. 95% of my woodpile is split