Moisture Content Of Firewood

[sfby]

Our chimney sweep has advised that we check the moisture content of the wood we put on the fire.

I've bought a meter and have checked a few of the logs we have for the winter, with most of them being OK at

[EcclesCake]

.......at?

[sfby]

Mmmm - it was OK on my screen...let's try again:

Our chimney sweep has advised that we check the moisture content of the wood we put on the fire.

I've bought a meter and have checked a few of the logs we have for the winter, with most of them being OK at 20% - at what point do I stop splitting / measuring? Or am I over-analysing the problem?

TIA

[Old_Geezer]

Unsure what you sweep said the problem was, but my guess is that, yes, you are being overly active in all the checking.

[Chipchopper]

I think its important to season wood properly, it can take 6 - 12 months to season well, for most hard wood, beech even longer 2 years for best results!

Any logs over 20% moisture content, simply stay back in the wood shed for further drying.

[diddlydo]

You can burn any wood. Stuff that's new and green i.e. with a higher moisture content will take longer to ignite. As far as the chimney sweep is concerned - let me just say that we've been in this house since new-build in 1976 and have only had the chimney swept twice despite burning all sorts of random wood plus paper, cardboard and anything combustible. When we have had it swept there's been virtually nothing there (modern liner, unlike old chimneys)

[jomifl]

If we assume that wood (cellulose) has a general formula of C6H12O6 then you can see that each cellulose 'molecule' contains 6 water molecules (which are released on burning) so 20% water content is only going to increase the amount of water going up the flue by 18% or so, not a big deal. Dry wood is good for starting a fire but not vital once it is going.When the fire reaches the stage where all that remains is glowing coals of charcoal no water is produced at all so a very dry hot exhaust dries the flue as the fire dies down.

[seadogg]

The enemy is creosote deposits which harden and become glassy and become a fire risk. These happen even with apparently dry wood. They can be treated by a product in the shape of a log which is burned in the stove. The fumes it gives off makes the deposits soft and brittle and those that do not fall naturally can easily be brushed. My brush rod set has lasted for years and saved a bomb on chimney sweeps.
Fitting a cowl also helps. For stove users, keeping the register plate above the stove clear is a great help in preventing chimney fires.