Why moisture matters
Freshly cut wood can be more than half water by weight. When you burn wet wood, much of the fire's energy goes on boiling off that water instead of heating your room. You get less heat, more smoke and more tar building up in your flue.
As a rule of thumb, firewood should be below 20% moisture to burn well. You can check with a cheap moisture meter: split a log and test the fresh face in the middle.
What are seasoned logs?
Seasoned logs are split and left to air-dry, usually for one to two years. Done well, this produces good firewood. But in Northern Ireland's damp climate, air-dried logs often stay wetter than people expect, especially if they're stored uncovered.
What are kiln-dried logs?
Kiln-dried logs are dried in a heated kiln, which brings the moisture down in days rather than years. This gives a more consistent result: logs that light easily, burn hotter and produce less smoke.
Which should you buy?
If you have plenty of covered space and can buy a year ahead, well-seasoned logs can work. If you want firewood that's ready to burn the day it arrives, kiln-dried is the simpler choice, particularly for modern wood burners.
