mm wrote:
A neighbor moved and gave me some old firewood. Really old it seems,
maybe 10 or 15 years old, and it was outdoors in the rain all these
years. In the fireplace, if there was a fire near it, a lot of smoke
came out the ends, and maybe the edges glowed, but there were never
any flames. When the other wood was burnt up, this wood smouldered
for a couple hours longer and turned into a little pile of ash.

Before I put it in the fire, the wood weighed a lot less than a normal
piece of the same size. Maybe half or less.

Is this typical, and do you know what happened inside the wood to make
it like this?

Is it the age, that it was kept outside, that it was kept uncovered,
or in the rain? Any way to store firewood succesfully for periods of
greater than 10 years?

Age alone doesn't make much difference except for drying. Weathering
does--it promotes rot and all kinds of other decomposition processes
such as fungi, insect infestations, etc., etc., etc., ...

The weight loss is undoubtedly a combination of both being drier than
green and weight loss from rot, etc.

Wood can be stored indefinitely if it is kept protected (mostly dry) and
not allowed to be infested, but it's work to do so.

I'd probably just continue to mix it in w/ the rest and use it up if it
produces a reasonable amount of heat and that is the purpose. If the
intent is for visible amenity of the fireplace, probably might as well
just chuck it.

--