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It depends on temp and humidity. I found a chart on the Web once, us forestry department I think, that have the wet basis MC for seasoned wood stored outside but top covered, by temp and humidity. Then using charts for average weather in different UK cities by month you can get the MC you should achieve. Iirc, South East should get logs down to about 17% but they will climb to 21% come February. SW is wetter as more humid but not much, up north and several degrees cooler temps the MC were a chunk higher. I can’t recall what, but by Aberdeen it could well be you’ll be looking at about 25% equilibrium mc, wet basis
Once it's dry hard wood is about 15%, anywhere, it can get damp outside but if it's already dry it will only be the surface, wood is hydroscopic but it can't rehydrate unless it's soaking, it's stacked outdoors in Norway and still gets there with colder wetter weather than the UK.
Building site (treated) offcuts, presumably you don’t have any neighbours! I’ve tentatively tried a couple of small bits, and a neighbour heats his wood fired hot-tube on pallets and it stinks the whole road out! Mixing wood and smokeless is also pretty harsh on the stove/flue as the water and sulphur create a corrosive gunk.
Just the white wood, tanalised will gas you and doesn't burn, untreated pallet wood is fine but not worth the trouble because it's gone in minutes, agree mixing wood and anthracite in a wood stove is not a good idea, hence why I have multi fuel stove, but you can put 4 or 5 bits on to keep it from going out without doing harm, no idea what the corrosive gunk is or where the water comes in?
If you are getting smoke the stove is cold, once up to temperature it will burn clean with pretty much anything but damp wood or tanalised(with a green tinge to it)
Just to say it varies massively.
May start to standardise on small loads in England due to Woodsure scheme, but over 2 cube could remain quite varied as can be sold with a note saying that you should season it - it will probably be the same stuff you have been buying for years if it's your regular supplier.
So much here I'm selling it to make space for more 😉
I think the best tip is get a moisture meter, another is cut dead standing birch, anyone will let you have that and it dries in no time.
as much as i can !
here you go espresso, not quite as i rembered outside SE, but you will see the variations across the months.
it doesn't go into depths on rate of change, which we all know depends on split size and wood type as well as the weather, but many firewood logs will gain a few percent MC between October and Jan IME
as for wood stove vs multifuel, the construction differences are just the grate for coal, I'm afraid the rest of the stove is usually identical. The stove isn't such a problem as the flue though. burn wood and the combustion products are h2o and co2, quite a bit of both, most smokeless 'coal' is actually an oil product and some of the brands contain quite a bit of sulphur, so while I wouldn't know if it's 'gunk' spooky is right, wood and smokeless coal burnt together creates a very corrosive flue gas, which can cause problems.
What sort of problems?
I just looked at that document...ooft, I have been burning wood for 7 years as my only heat, and I have a moisture meter, and it reads 15% when it's dry, some take longer than others, and it varies by about 3% between seasons once dry, oak same as birch same as rock hard hawthorn, ok I'm only in one place and can't speak for other places but if I can get 15% in Scotland I'm fairly confident everywhere south can too.
Also, yes cheap stoves turn into multi fuel with a different grate, but coal, anthracite and wood all burn optimally at different temperatures, you can get this by changing the flue to burn quicker/hotter, or a dedicated stove, the difference is in how much fuel you need to burn per heat out of it.
if its a £5 moisture meter like mine or most, it doesn't read wet basis, it reads dry, it isn't calibrated and setable for different wood types and consequently its exact reading may be out, its a guide but not gospel. If it doesn't have a setting to offset for temperature, and cheap ones don't, then do you take the wood inside for several hours to let it warm to room temps? as its 'calibrated' for use at about that temp. I presume you then resplit the log and read the mc inside the log at several spots, jamming the pins in hard and do you place the pins across or along the grain? cheap meters are just a guide.
I agree you can air dry down to sub 20% and I see little point in kiln dried (unless you can store it inside, or don't have a decent supplier of ir dried). As I said, I've 30 cube in the garden, half of which has been CSS for the last 2 summers and I'm confident it is dry and ready to burn.
the SO2 reacts with the H2O to form H2SO3, a strong acid. with a stainless lined flue of 904 it will resist this to a fir extent but not perfectly, a 316 liner can rot in a winter or 2 of heavy wood/smokeless mix use. if not metal lined I believe the acid can attack the mortar
I live on 6 acres of hardwood, mainly eucalypt. Fell them very occasionally. It burns brilliantly, but the chainsaw really struggles it's so bloody tough.
We pay £80 for softwood and £90 for hardwood - west/north Yorks border. It's nominally a cube but the yard has a front loader with a small bucket and they just scoop a load up from the pile. Fills about 1.2m^3 in our woodstore when packed reasonably well.
Many years ago I worked on a building site and took the offcuts home. However with the site being for a hotel all the timber was treated with fire retardant! That didn't go well.
if its a £5 moisture meter like mine or most, it doesn’t read wet basis, it reads dry, it isn’t calibrated and setable for different wood types and consequently its exact reading may be out, its a guide but not gospel. If it doesn’t have a setting to offset for temperature, and cheap ones don’t, then do you take the wood inside for several hours to let it warm to room temps? as its ‘calibrated’ for use at about that temp. I presume you then resplit the log and read the mc inside the log at several spots, jamming the pins in hard and do you place the pins across or along the grain? cheap meters are just a guide.
I agree you can air dry down to sub 20% and I see little point in kiln dried (unless you can store it inside, or don’t have a decent supplier of ir dried). As I said, I’ve 30 cube in the garden, half of which has been CSS for the last 2 summers and I’m confident it is dry and ready to burn.the SO2 reacts with the H2O to form H2SO3, a strong acid. with a stainless lined flue of 904 it will resist this to a fir extent but not perfectly, a 316 liner can rot in a winter or 2 of heavy wood/smokeless mix use. if not metal lined I believe the acid can attack the mortar
There are a lot of strange SO2'S and H2SO3's in there, I have a bog standard steel flue that has not needed swept in 7 years, it's not rotted, and smoke doesn't get near mortar??
I took my cheapo moisture meter into work to calibrate it with one that cost several hundred quid, it was the same reading, and if you split dry wood it's the same moisture content on the inside after splitting, it only varies if it's still drying and not ready.
You don't burn smokeless anthracite and wood together, there would be no point, you use the nuts to burn longer, the wood burns away and you switch over to anthracite, similar to anyone starting a coal fire with kindling.