Hardwood trees are known as angiosperms and produce seeds that are covered, either with a skin or a shell. By example, Oak, Ash, Beech, Cherry etc.
Hardwood logs are generally preferred as they tend to burn longer, hence produce more heat over time. Most hardwood burns well, however, some types burn much better than others. Ash is generally seen as the wood of choice. It has naturally low moisture content and could, theoretically, be burnt straight from the tree – whilst not to be recommended. Oak burns more slowly, Elm tends to smoulder, Beech burns bright. A chart will follow shortly.
All firewood needs to be seasoned to a moisture content of around or below 20%. Much higher than this and a lot of heat energy is wasted by producing steam, as the moisture is lost.
Generally a variety of seasoned hardwoods are selected to make up a ‘load’. A load equates to one ‘dumpy’ (builders) bag. Loads can be supplied loose, by the dumpy bag, or in smaller nets.