Mixing Kiln Dried and Seasoned logs

October 29, 2014

Often our customers ask us if it is ok to mix kiln dried logs with firewood that has been cut locally or sourced from their own property.  The answer is ‘Yes, as long as you have dried it properly!”.
Home-grown firewood can be a great money saver , but  if it contains too much moisture you will not get the best heat output from your stove.  The aim when drying logs is to get rid of the moisture that is in the cut logs.  Typically a cut log can have up to 60 -60% moisture. Now, it is worth stating here that ‘air-drying’ or ‘seasoning’ your logs is unlikely to get your moisture content down to 10-20%, which is the common range for our  kiln dried logs. However, by following a few common-sense steps, you should be able to achieve a moisture content of  20-25% through natural drying. A method we often hear about involves starting the fire with very dry kiln dried wood or heat logs, and once the flames are well established and the room is properly heated, switching to seasoned logs.

Drying your logs

It is important to know that the water in the wood consists of two types. The first is known as Bound Water. Bound water is the water that is trapped inside the material that makes up the fibres or ‘veins’ of the log. The second type is referred to as free water. Free water is the sappy water running between and alongside the fibres of the logs.

It is this free water that is easiest to remove from timber and it will also be the first to evaporate during the air-drying process (note – it is the stubborn bound water which is best removed with kiln drying, but this is another story). The point to all of this is that when you cut and stack your logs, you can expect faster drying with short logs and a stacking pattern that exposes the ends of the wood fibres, where the free water can easily escape. The picture below shows a typical well-formed air-drying stack, with logs ‘ends out’:

Logs drying
Logs drying

The two basic rules when drying your own logs at home:

  1. Maximise Air Flow: Water is carried away from wood by saturating the surrounding air, so if you can stack your logs in some place where there is a consistent breeze, you wood will dry much faster.
  2. Avoid Direct Contact with Water: Ensuring some overhead shelter, by stacking against a wall or using a makeshift roof, will prevent rain directly hitting your firewood. Likewise, elevating your logs off wet ground or grass, by placing bearers underneath your log stack, will ensure your firewood does not absorb ground moisture.
Logs  -  in Log Storage cabin
Log Storage

A simple but effective way of meeting the above requirements is to buy one our log stores. A purpose-built log store will provide protection from rain as well as ground clearance for your firewood. Best of all, a log store has a huge benefit in that it can be moved to where the air-flow or breeze is sufficient