Have about 10 face cords of Oak cut and waiting for me on the front lawn for spring/summer. Been always told that once Oak is Split & Stacked wait a good 3 years before burning. With that said...What about Rounds? Now some of my rounds like Ash, Maple or Cheery ...I leave them at about 8" or so...After 2 years..great for a long night time burn....Now Oak on the other hand..not sure.... What's the biggest diameter I can get away with?....
Leaving rounds whole for "all nighters" is really just leaving moisture inside to require boiling off and cooler burning temps. With Oak unless these are tops from a dead stander I'd split down to 4-5" rounds. You may even still find some sizzlers 3 years from now
Split & it seasoned faster. Try some you think are ready, see if you get sizzling water out the ends. I make overnighters our of big rounds , make some 4" x 4" s & some 4" x 6"s & put them in the center of the overnight load.
I try very hard to avoid round (i.e. never less than 1.5" diameter). Splitting them in half reduces the time to dry them by a huge amount. Basically, if it's worth saving for firewood, it's worth splitting in half to me. That said, I burn a modern, EPA, secondary-burn stove.. If you burn something else then you should consider the cost vs. benefit of splitting small rounds.
As said, at least split it in half. It will season faster. It will dry way better with at least the center of a log (wetest part) exposed to the air. Make some bigger square or rectangular blocks out of the heartwood from the largest rounds for over nighters. It's denser wood and will burn a little slower and hotter.
When I split wood, I split to the size I want/need to use. Not to the size where it dries the quickest. I would also leave some larger splits as two of my epa stoves are smaller and the longer burn times are nice with a larger split. That being said, it the overnight burn splits are substantially larger, they make not dry on the same time schedule as the smaller sized splits. One more year for those then, no?
I am like yooper, splitting for the sake of drying is a lot of extra work. If you are on the 3 year plan, I suggest leaving them intact up to the biggest diameter you can fit into your stove. I have 12 inch rounds of cherry, hickory and maple I burn. It's a fight sometimes getting into the stove, but after three years it burns great. Get it up and stack and out of the rain asap. I am certain you will enjoy the long burns later
I used to burn a lot of 4 inch or so Oak rounds and they burnt fine with no sizzlers, dead when cut and burnt when only a year old or so, contrary to some popular beliefs, rounds will dry and probably quicker then many think as firewood dries from the ends a lot even when split. If I had to guess I would think 6 or even 8 inch would be a good size if you have the time to let it dry, it will take a good coal bed to get it going though. A 24 inch long round will obviously take longer then a 16 inch round.
Another thought is what stove do you have, not sure my Drolet will burn Oak rounds any bigger then about 4 inch but my Nashua well eat 8 inch Oak rounds and ask for more.
Our sort of rule of thumb on rounds is 5-6" maximum but for oak it is more like 4" maximum. You state you've been told 3 years before burning and that is great advice no matter the wood. Yes, some wood you can burn sooner than 3 years with no problem but one nice thing is that as someone wiser than me has stated, there is no expiration date on dry firewood, so long as it is at least top covered. Take one of my favorites, which is soft maple. We've burned it in as little as 6 months after being c/s/s, yet it is still super after 3 or 4 years. We've burned some already this year that has been stacked around 6 years and it burns wonderfully.
I'm with basod.......anything over 5" gets split at least once, ESPECIALLY oak. The only exception is, as he stated, if the trees were barkless, standing deads. Then I'll leave rounds, sometimes even up to 10" diameter, in one piece......
I leave a certain amount of rounds at 6" for overnite burns, oak included. My firebox is huge, & stove is non EPA. If they sizzle or smoke I let them go another year. I'm fortunate to have enough wood put up for a while. Oak dries 3 yrs round split or otherwise. My furnace will ingest about anything, but I don't like creosote or smoke.
I never thought of using rounds to extend the over night burn. Will a 6" round peice of dry ponserosa pine take longer to burn then a 6" split peice of dry ponderosa pine? Assume split peice is roundish enough that they both have same mass.
I think a lot of it has to do with what's available for burnable surface area exposed to flame. A round generally seems to take longer to light up, and to burn up in my experience. But when I do hero type tetris loads in my little stove, I can get long burn times (relatively speaking of course!) with square wood, because it's burnable surface is not all exposed at once.
Rounds definitely dry, but not as fast as splits. If you burn a lot of sweet gum and elm and split by hand like I do, you experiment with rounds. Cutting the rounds short speeds up the drying time, but if you get short enough, you need bins because you can't really stack them. The upside and downside to rounds is that they have minimal surface area to volume ratio. So, the drying will be slower, the burning will be slower, and the ignition will be slower than for an equal volume of wood that has been split.