Can fire wood be too dry?

[dodge man]

I burn my wood in a fireplace and for some reason I’m getting a lot more ash this year. I’m mostly burning hickory now but some oak and elm. Somebody I know went by the sound and said the wood was pretty dry. I’m getting about 50% more ash for some reason.

 

[ponytug]

I burn my wood in a fireplace and for some reason I’m getting a lot more ash this year. I’m mostly burning hickory now but some oak and elm. Somebody I know went by the sound and said the wood was pretty dry. I’m getting about 50% more ash for some reason.

Residual ash levels are related to how and where the tree grew, and is mostly unrelated to moisture content. The bit that is related to moisture content is that if the tree grew on soil with a lot of chloride (think table salt) on it, the salt will cause the wood to retain more moisture compared to wood grown on less "salty" land. Calcium and magnesium do not generally have the same effect as they tend to be in the form of organic salts and carbonates that are not especially hygroscopic.

Different species of trees concentrate different amounts of sodium/potassium/calcium/magnesium, and rarer elements. In the old days, ash from certain trees had preferred uses in pottery glazes and metal working.

All the best,

Peter

 

[jaxs]

I’ve been told that a 15~20% moisture content is preferred for firewood otherwise it burns too fast.

90cummins

OMG,Ben Told and his stepbrothers I Heard and They Said are the biggest liars in the country,never believe anything they say.
The drier wood is the more btu and less creosote it yields.

 

[5030]

Not that I probe wood because I don't but my Delmhorst moisture meter I use in hay ad wood probes with it I've never used.

 

[wmfamily]

We would just thin out the trees that had been dead a couple years or we blown over and had a chance to dry out. We'd ring the nasty thorny locust and let them stand a couple years too before cutting them down. When we boys were young and not so smart we split wood with a double bit axe and thought we were really doing great when we got a splitting maul.

We burned everything from oak to walnut (no pine) and as long as it was dry it was OK. Some wood makes more ash, some wood makes better heat. The only thing we didn't burn was osage orange. We learned the hard way that it got too hot and would burn out the bottom grates in the stove. That was the old stove from the late 60s and definitely didn't have an EPA sticker.

 

[dstig1]

It would be pretty hard to get regular air-dried firewood "too dry", but you can run into it with kiln dried wood. I burn a lot of my offcuts and other scraps from my wood shop, and that stuff is all very low moisture. I am careful to not go too crazy with it and only add "some" of the scraps to regular firewood so I can both get rid of it and not make the fire so hot that it could damage the fireplace. It also helps a lot on getting the fire started from cold (kindling).

Our woodworking group toured a glulam manufacturer nearby once and they said their guys love to take offcuts home to burn but need to be careful since they are so dry as some have damaged their stoves in the past by loading in too much of the dry stuff. Those tended to be bigger chunks too, so they had a fair bit of mass that would add to the heat.

So there is the real-world context on what too dry can mean... Not gonna happen with split firewood.

 

[90cummins]

I don’t have a moisture meter but being stacked in same area as wood furnace which is 70~80+ degrees I would wager that moisture content is in the single digits.
When thrown into furnace they start burning immediately.
90cummins

 

[Larry Caldwell]

Different species have different amounts of ash. No hickory around here, but oak has more ash than madrone. I don't burn d. fir-larch, but a friend who does says it is low ash too. Black cottonwood is horrible for ash and is almost worthless as firewood.

 

[dougtrr2]

I am using a WoodGun boiler from Alternate Heating Systems. When you get the boiler there is an EPA plug in part the the draft system. When I talked to them about it they said the testing done by the EPA is done using kiln dried 4x4s. The only way to get the furnace to meet the EPA specs at the time was to install a plug. In actual use the furnace operates better without the plug. So moisture content does make a difference. Base on this limited experience I would say yes, maybe wood can be too dry,

I have found different woods produce different amounts of ash and heat. I will not burn cotten wood or rock elm. Too much ash, not enough heat.

Doug in SW IA

 

[oosik]

We built a log cabin when we lived in Alaska. We burned birch in the wood stove. It was the only wood available in our area. It grew in thick stands. Like standing white spaghetti.

A BIG birch tree would be 5" or 6" on the base and 40 to 60 feet tall. Birch will burn well when green if added to a hot fire. Birch will turn to powder after a year or so when racked up to dry. It's a very easy wood to cut with a chain saw. Cuts like butter.