Recently my partner and I started to look in to buying our first home together. Having studied Interior Architecture at university it is fair to say that I am going to be the picky one in this process. I love everything design related and as my other half so politely put it, I am a nightmare when it comes to choosing a home. One thing I do know however is that I have a love for exposed brick and wooden beams. Its beauty is outstanding and it was during this home searching that I wondered how timber can be manipulated to go from a twisted, distorted beauty to a clean and smooth beauty such as found in our worktops.
Most people have seen old beams in buildings where the beams are all twisted, split and warped. Whilst this is fine for a building, the same cannot be said for a wooden kitchen worktop. Once it’s in situ, you want it to stay stable, flat, and not start cracking and splitting. Of course as any timber adapts to its environment, and any changes in that environment, it will move but with correct treatment, installation and maintenance this will significantly reduce these changes to the point where they are unnoticeable, however it still requires that the timber was dried correctly in the first place.
As soon as a tree is felled, it needs to be planked and laid out ‘on sticks’. These should be about 12-18” apart allowing the air to flow freely around the timber aiding the drying process. This must be carefully regulated to prevent the timber from drying unevenly or too fast, which introduces exactly the problems we are trying to avoid. One of the first steps to stop the timber from drying too fast is to paint the ends with a wax based paint. Where the end grain is cut, it exposes the capillaries which carry water and nutrients up and down the tree, so clearly significant moisture loss will occur at this point. Painting with wax maximises this, and forces the moisture to flow out through the sides of the timber evenly.
The next step is to place the stack of timber, in a shed called a ‘T’ shed. This is simply a roof to keep the sun and rain off, and also to provide a fixing for ‘curtains’. The curtains are made from a tight mesh that allows air flow, but crucially stops wind from blowing over the timber. Wind is a big enemy when drying timber, as it takes the moisture out too quickly, and leads to splitting. It is also a good idea to place a few sheets of thick ply on the top to weigh it down and hold it flat. Once all that’s in place, the timber should be left for a minimum of six months, but preferably 12-15 months.
After this, the next stage is to kiln dry the timber. The kiln drying process is where most of the damage occurs from trying to dry the timber too quickly. Running a kiln costs around $ 12,000 dollars a month for a 120 cubic metre kiln, so it’s easy to see why most companies rush it. It’s not just a matter of putting it in the kiln, turning the heat on and leaving it for three months either. The temperature needs to be built up very carefully so that the balance between the core moisture content of the timber and the surface reading are never too far out. Too much, and the moisture is being forced out too quickly, and will split and damage the fibres of the timber, which will then be in there forever. Modern kilns use an array of moisture sensors to ensure evenness of drying.
Once the timber is down to around 6% moisture, it is then conditioned with heated steam back to up to 7.5%, which makes the timber stable. Obviously each step adds complexity and considerable cost, but without these elements, production of quality dry timber is all but impossible. Timber which is force dried too quickly will eventually equalise, however during this equalisation it will almost certainly warp, split and crack. High quality timber is something we will never stray from.
As my parents always told me, if you’re
going to do something, do it properly
otherwise what is the point in doing it?
