Don't be scared by stories of shrinking and movement in Green Oak. It is often the best product for constructional uses. When used with traditional mortise and tenon jointing methods the Oak will shrink a little yes. Mostly in the girth however, clever and time tested framing techniques will use these properties to an advantage. As the Oak shrinks slowly over time the joints all shrink in conjunction with each other creating much tighter joints and overall a more stable Oak Frame. Freshly sawn oak usually left to settle in the log for about 12 to 18 months. There are some oak suppliers that we are coming across at the moment that are using very green oak that is newly cut. Be aware that the price may be cheaper but the quality will definatley suffer. Oak beams for Roof Trusses and Green Oak Timber Frames need to be chosen specifically for the purpose to avoid twisting and undesirable movement.
The softer Green Oak is sawn, planed and the required joints (mortises and tenons or other) are then cut.
Green Oak Beams do shrink, age and split however this should be seen as the quality of the timber and adds to the character.
As the timber dries in situ the Oak hardens further and is one of the toughest building products available. The proof of this is evident in the historical structures all over Europe that have stood firm for hundreds of years.
Your builder, engineer or architect may have a preference for either Air Dried or Green Oak. We provide both and have not had any complaints or issues with either. It is a matter of preference of the designer or builder. So too is the type of joints and fixings requested. We also supply the Wrought Iron Mongery which is a durable and specialised feature for the design oriented.
This is a natural and environmentally friendly method of drying Oak to a moisture content of between 20-30% fluctuating slightly with atmospheric conditions i.e. humidity and temperature. Properly stored Oak logs are left to rest from between 5 to 10 years or more with adequate ventilation between the logs which is paramount.
Using Air Dried Oak reduces issues of shrinkage and movement of wood in the final construction.
Ultimately Air Dried Oak can be described as hard as Iron. We can certainly attest to that as even with excellently maintained and constantly updated cutting machinery, we need to constantly change our chain blades and the Air Dried Oak often strips the metal teeth of the blade.
So basically the lengthier times in production in our workshop and the times involved in Drying the Oak add the price of the finished product.
Having said that it is by no means out of reach of the average builder looking to install these beams.
Many of our clients find the small extra investment worthwhile and if your considering this building material we are very happy to provide a comparison quote of both Green and Air Dried Oak.
Oak of this nature is taken and dried in large Kilns. Due to the amount of energy required by this process there are thankfully now producers of Solar Dried Oak of the same quality.
Where possible & costs allow we will always endeavour to source Solar Dried Oak for the use in our production of RSJ Beam Casings.
When talking of either Kiln Dried or Solar Dried Oak the properties of the wood are very similar if not indistinguishable.
Kiln and Solar Dried Oak is mostly referred to as Furniture Grade Timber.
The moisture contents are minimal and therefore shrinkage and movement reduces however only to a point.
All timber will move and adjust to the final inhabited environment. For instance the noises in a wooden house during the changing seasons and weather.
Kiln or Solar Dried Oak is more expensive and seen as a premium craftsmens' product for specialised projects.
Price on application.
Oak Beams, Roof Trusses,
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