green logs

[likeitorlumpit]

This probably been discussed before but here goes

I've always been told to season most wood esp. oak for a couple of seasons.

I know ash/birch/holly and some others ok without

But this week we have cut down a few big oaks and our woodburner is burning like a furnace with chunks of green oak on it- though started with kindling(nice and dry). I noticed this last year with green cherry too

Does anyone know if there are any detrimental effects from doing this- In fact the room is currently too hot to go in- only a 5kw stove though.

Seems to me a mix of green birch/ash/oak with 2 or 3 week seasoned poplar kindling makes a good combination without the hassle of long term drying.

Any thoughts?

[Tree Man Tom]

Your chimney will tar up very quickly burning wet wood.

[detritus21]

You'll be burning more green wood to get the same heat as seasoned as you have to boil off the water in the green logs so energy is taken up doing that.

[likeitorlumpit]

This is what I don't really grasp

Why will the chimney tar up

There is a good draw

The fire is very hot meaning the liner is also hot which I thought meant that tar wouldn't condense out.

I get the thing about using energy to dry out the green logs- but I have tonnes of wood so this isn't an issue- we just load up the fire maybe a bit more than usual- though it doesn't seem like it.

I can understand that burning green wood on a poor fire that is struggling to get going would be bad news for the chimney as it wouldn't warm up but this isn't the case- the fire burns like a good 'un.

I'm challenging conventional wisdom maybee

If you can burn green ash then why not green anything so long as you have a hot 'healthy' fire

Thanks for the replies- I just want to get this straight

[Big J]

Moisture content varies tremendously depending on the different species, for instance:

 

* Ash has a moisture content of around 37% when felled

* However Elm can be as high as 120% and sycamore as much as 140% (depending on when cut). Pine sapwood can be as high as 200%. Oak is typically 62-68%.

 

You might find that Ash will burn and perhaps Oak too, but you really would be better just sitting the logs to dry for a year. That way, you have less weight to carry when bringing in the logs, more heat and less chance of gunking up the chimney. Creosote will form according to flue temperature, but if you are burning very wet wood, you will struggle to achieve as hot a fire, resulting in a greater chance of tarring.

 

Hope this helps.

 

Jonathan

[Big J]

Moisture content varies tremendously depending on the different species, for instance:

 

* Ash has a moisture content of around 37% when felled

* However Elm can be as high as 120% and sycamore as much as 140% (depending on when cut). Pine sapwood can be as high as 200%. Oak is typically 62-68%.

 

You might find that Ash will burn and perhaps Oak too, but you really would be better just sitting the logs to dry for a year. That way, you have less weight to carry when bringing in the logs, more heat and less chance of gunking up the chimney. Creosote will form according to flue temperature, but if you are burning very wet wood, you will struggle to achieve as hot a fire, resulting in a greater chance of tarring.

 

Hope this helps.

 

Jonathan

[likeitorlumpit]

So

really it's not necessarily a question of moisture content although that will result in heavier logs.

It's all about hot fire resulting in hot flue resulting in less deposits.

I never had a chimney fire in many years of fires though I have had the process described to me- vibrating house/ much smoke/much fear

In the past I only really burned wood on open fires in grates and there was little benefit in using green wood as it usually burned slowly if at all.

Todays woodburners are more like furnaces and I think that means we can get away with using green.

Anyone else with views or maybe someone on here has done some research projects- I know it's not really degree standard stuff but is becoming a valid area for research

[Bolt]

Moisture content varies tremendously depending on the different species, for instance:

 

* Ash has a moisture content of around 37% when felled

* However Elm can be as high as 120% and sycamore as much as 140% (depending on when cut). Pine sapwood can be as high as 200%. Oak is typically 62-68%.

 

You might find that Ash will burn and perhaps Oak too, but you really would be better just sitting the logs to dry for a year. That way, you have less weight to carry when bringing in the logs, more heat and less chance of gunking up the chimney. Creosote will form according to flue temperature, but if you are burning very wet wood, you will struggle to achieve as hot a fire, resulting in a greater chance of tarring.

 

Hope this helps.

 

Jonathan

 

I am confused.

 

Surely just water on its own has a water content of only 100%. How can a log have a water content of more than this, there wouldn't be any volume left for the wood.

[Big J]

If you regard the absolute dry weight of the timber as 100% and for example that weighs 500kg for a cubic metre. If that timber has 250kg of water in it, it has a moisture content (MC) of 50%. If it has 500kg of water, it has 100% MC and so on. Moisture content is based on the weight of the dry timber, not the percentage weight in the green timber, if that makes sense!

[Bolt]

If you regard the absolute dry weight of the timber as 100% and for example that weighs 500kg for a cubic metre. If that timber has 250kg of water in it, it has a moisture content (MC) of 50%. If it has 500kg of water, it has 100% MC and so on. Moisture content is based on the weight of the dry timber, not the percentage weight in the green timber, if that makes sense!

 

Cool, I can see how that works (your explaination even works for pure water). Cheers for explaining.

 

 

 

 

 

 

Now you see why I ain't a 'logs' man