Tree Top Pointing Downhill and the Forces of Nature
The old wood workers say: "If you want quality building wood, the best way is to cut the trees and have them lying with their tops pointing downhill for a few weeks before you cut off the branches." Why? When a tree is cut down, it wants to procreate one more time.
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Trees or fresh logs contain large amounts of water often weighing more than 50% of the trees' weight. Every piece of wood, no matter if it has been used for furniture, roof trusses, toys or building, contains only a fraction, approx. 6-20% moisture content.
In the following chapter you will read about the other requirements you need to consider to produce high quality building wood. This natural resistance is the basis of wood preservation without toxic chemicals and the secret behind the durability of wood buildings which have survived hundreds and sometimes thousands of years without damage. 'Natural wood protection' means to harvest the trees at the right time and dry it in ways which further protects it from insects and fungi.
How Much Moisture is Appropriate?
It is not only the growth of the tree which depends on water. The moisture content attracts fungi and insects which potentially cause damage to wooden buildings and artifacts. The question is how much moisture is left in the wood? Below 20% moisture content, wood is protected from fungi and below 8-12% from insects. I don't play the oboe and I can't proof this musician's story, but it made me ponder anyway. I am thinking about the wood stacks which have been stored for years in our mill and remember business experts calling it 'dormant capital'.
However, the point is, when it comes to making the best instruments, slow and naturally dried wood cannot be produced by any modern kiln. New techniques like pressure treating wood with hot oil are being used to manufacture wood instruments. The Musician's comment was that these instruments look nice - and are not as prone to cracks, however their tone is different. Even though they are manufactured very well, they are only suitable for beginners and school purposes, not for the use in orchestras. "This wood just doesn't sound right anymore."
Oboes and clarinets are manufactured from black Ebony. Traditionally professional instrument makers used to store Ebony for 20 and up to 30 years before using it to build fine musical instruments.
In recent years the demand in Europe for these instruments rose steadily. This means that nowadays, there hardly is any oboe made of wood which has been dried and stored for that length of time. Musical Instruments and Moisture
The following story shows the importance of the moisture content or humidity levels on the drying process of wood. An oboe player, who has become famous in Claudio Abbados' Youth Orchestra and works for several European concert and opera houses, has told me about his observations: Once you want to know where the wood came from, the seller will ask his supplier. Soon the saw mill and forester will be confronted and this will cause them to start sorting their wood accordingly. The end result of all these efforts will be buildings, toys, furniture and other wooden items free of chemicals and toxins.
We and the next generation need to take this opportunity to build a healthier and more sustainable lifestyle. I gleaned these insights from my experience of processing many thousands of trees from the forest to the finished item. The formula is always the same: observe nature and act accordingly.
To consider the origin of the wood is not only relevant to the forest owner or other wood professionals but also to the end consumer. A spruce grown in unnatural circumstances is inferior in quality and less durable compared to one which grew in its natural environment and conditions.
Taking this a step further, I would not use wood from monocultures in low-lying areas for a job like a winter garden or glass facade. The demands on the frame are high and the wood must be stable and calm. Due to Holz100 technology, even large projects like hotels can be built with solid wood. Holz100 offers fire safety sound insulation, security and comfort at a level unmatched by normal building methods.
If one compares the end product of wood grown in its natural environment with wood grown in a monoculture, one can see the qualitative difference. As important as it is to have stable and calm wood, the question has to be asked, if it is useful to demand this characteristic for all other cases (like furniture, floor etc.) as well. My answer is 'no', because wood is a natural building material, it is alive and working. Particularly demanding requirements like motionlessness often lead to the widespread use of glue laminated products (e.g. engineered flooring) which result in huge ecological problems like toxic waste.
A rafter with the intention to warp or twist is never going to be stopped by a glass panel. This glass panel too would splinter with the slightest twist. When looking at this construction, I just admired the clients' trust in our beams and saw this as an experiment and a strange way of measuring the possible movements of our beams. After four years, this panel is still intact and in its place. The experiment can be called successful and shows that even for very difficult and challenging tasks it is worthwhile to consider the possibilities nature offers.
However, he wanted daylight to come through a transom window from the entry into the bathroom and planned a glass partition sitting on the internal wall. The fact that the exposed ceiling rafters were running through both, the entry area and the bathroom, didn't bother him at all. He went to the glassier and ordered a glass panel with an exact square cutout for the wooden rafters.
The architect was so convinced by his success that he then decided to design more components for his house. It made the hair on the back of my neck stand up when I first saw his plans. The ceilings upstairs were built to expose and show the long and continuous rafters and the internal walls dividing the rooms were built up to the rafters.
When I hold talks, I sometimes ask the question if any of the carpenters, joiners or cabinet makers is able to mount a five-meter-high glass panel on solid instead of glued laminated joists. Their answer is always hesitant, uneasy and negative. Have crafts people too lost their trust in this wonderful building material? We only need to progress thoroughly, step by step and there won't be any need for toxic and harmful synthetic building materials or chemicals in any area of any home. Every builder should reflect on this.
Every expert knows that dangerous movements of wood in a situation like that happen in the first year and rarely later. By now, 12 years have passed, 12 hot summers with heat and 12 alpine winters with frost and snow on the glass outside the wintergreen. The five-meter-high glass panels still rest without tension on the wooden frame joists as they did on day one.
We eventually got the job for this building and went ahead in our usual manner. I went out and looked for spruce trees which were growing in good forest soil at about 1,400m above sea level. The logging took place in winter, at the waning phase of the moon. It was stacked and dried the same way we always do it. The large glass panels were fitted with our wood and the family was happy with their wonderful winter garden. Not quite a year later, the building was finished.
Any slight movement of the timber frame would put tension on the brittle glass and cause it to shatter. For this reason, the architect wanted to use engineered wood to be safe rather than sorry. He didn't approve of using solid wood at first. The home owner however was aware of the toxicity of most wood glues used in engineered wood products and wanted to avoid this in their new home. Therefore they were looking for solid timbers. The beams needed to be cut from large logs.
One of the most difficult and most exciting tasks were proposed by a young family in 1992. They were planning a winter garden for their new family home. However, the design was different from previous builds by us. The architect had specified the largest size of glass panel that could be transported. Our frames were to house five-meter-high, double-glassed panels. The architect was aware of the challenge this posed.
If you plan to use large glass panels in a building, the need for absolutely stable and motionless wood becomes a matter of life and death. Any movement, ever so slight, would become obvious when the glass panel breaks. We have been manufacturing wooden elements for large glass panels for quite some time now and even though it has become routine, it still is important to design a home well when using glass and wood together.
No one is annoyed by the fine cracks and as long as the roof shingles are kept in good shape, this cabin will still be here in a few hundred years. When exposed beams in a house twist and have fine cracks, it is more a matter of taste and visual appeal than structural integrity, because the load-bearing capacities are hardly affected.
Wood and Glass - the Hour of Truth
On this wonderful July morning the sun is warming the outside walls of the little log cabin in the 'Hohen Taueren', where I made myself comfortable with pen and paper. The sun, wind and weather have colored the wood and blended the cabin into the surrounding environment better than any artist could ever have done. Our logs had been cut into boards in spring and stacked to air dry before the hot summer came along. Because of these Swiss pine logs, we now had strong evidence that the moon and the harvesting time of wood had an influence on longevity and resistance to insects and fungus. We also came across larch and spruce trees which were not attacked by anything either.
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