When we talk about “green oak” we refer to oak wood that is between 3 and 18 months old.
This wood is very interesting, especially for people who work in construction; it doesn’t need any treatment to be used.
So, follow us and we’ll show you how you can save money if you choose it as raw material for your projects.
Why work with green oak wood?
First of all, we should clarify that the term “green” refers not to the color of the wood but is rather a way of describing the freshness of this recently harvested material.
On the other hand, unlike other woods that need treatment with chemicals to increase their lifespan, freshly cut oak wood can be used both indoors and outdoors without any treatment.
This is because, at the moment of being cut, oak wood has a moisture content of 60% to 80%, which begins to decrease immediately after the wood dries naturally, i.e. in the open air.
This process is known as “seasoning” and consists of the hardening of the wood as it dries.
This makes the wood (naturally) more resistant over time and less prone to damage caused by excessive moisture.
However, the seasoning process can take about a year to complete so it is not a quick process.
Thus, seasoning can take one year per 1 inch (2.54 cm) width of the wood; this means that if we have a beam of green oak about 5 inches (12.7 cm) wide, for example, it will take about 5 years to dry out completely.
Remember that wood is considered dry when it has a moisture content of 12% or less, and with seasoning, we can achieve a moisture content as low as 4% if the environmental conditions of the place where the wood is stored are optimal.
Factors to take into account when using green oak wood
Despite the advantage of not having to treat this wood, we have to mention some characteristics of green oak that you should take into account before buying it, because if you don’t, you may end up working twice as hard if you choose it.
Green oak shrinks
This wood tends to suffer a certain degree of shrinkage as it loses water, which causes its mass to shrink.
Therefore, before starting any work with green oak, you should consider this factor.
An example of what can happen is seen in the construction of window or door frames with this wood since, when shrinking, the frames can break the glass, and doors may not close because they are smaller than the frame that holds them.
What does green oak shrinkage mean?
When it shrinks, wood can lose stability and strength. As a result, built-up structures can weaken as the joints shrink and are no longer able to hold together.
That’s why we said before that if you don’t take this into account you may have to work twice as hard because now you’ll have to repair the joints so you’ll lose time and money.
But it’s not all bad
In contrast, this degree of shrinkage can be very useful if that is what you are looking for because, if the joints are shrunk in a controlled manner, they can be greatly strengthened resulting in extremely stable structures such as temples or houses.
In fact, traditional Japanese carpentry uses this type of joint since in this art no glue or nails are used. Instead, very precise cuts are made so that the pieces of wood fit together.
Thus, as the pieces dry, their joints will become stronger.
How durable is green oak wood?
In general, European oak is more durable than other species because of its low water content.
In addition, if this wood is seasoned, the chances of decay are drastically reduced, as dry wood is a hostile environment for pests, especially fungi.
Also, Oak wood can last for centuries without being changed when it has been used in “green,” due to its great natural resistance provided by the high concentration of tannins it possesses.
Note: remember that tannins are chemical substances present in the wood of most hardwoods such as Oak, whose role is to protect the tree from wounds, as well as from pests, as they are toxic to insects that try to eat the wood.
How easy is it to handle green oak wood?
Although industrial wood drying, i.e. the use of industrial kilns to dry the material, is much faster, it is also significantly more expensive.
In contrast, the seasoning process is economical but slow. However, it has a great advantage because the wood is “softer” and, therefore, easier to process.
This is very important because oak wood is hard and often presents difficulties, especially in sawing, although in general, its workability is no different.
That is why “green” oak is an interesting alternative for carpenters. The fact that it is easier to work with means that fewer specialized tools are needed; this reduces construction times and costs.
Cost of green oak
We have already mentioned that green oak is cheaper than industrially dried oak, but… How much exactly?
Well, what we can tell you is that “green” wood can be 5 to 6 times cheaper since industrially dried wood often requires subsequent treatments that increase the production costs and therefore the prices to be paid by the end user.
In addition, since green oak wood is freshly sawn, it can be cut to size required by the customer so there is no need to buy standardized presentations.
An inconvenience that usually happens with other woods, so you often have to buy more than what you need, which contributes to the waste of wood.
On the contrary, with “green” wood you can get the piece you want exactly as you need it.
This wood makes it easy to customize sizes, so if you know exactly the quantities you need for your project, you won’t have wood left over.
Carbon neutrality
Wood is the building material with the lowest amount of embodied carbon dioxide according to a study by the UK Timber Trade Federation.
But it is worth clarifying that to achieve this carbon neutrality, the green oak must be sustainably sourced, i.e. oak must come from forestry plantations used solely for timber production.
Why does this happen?
As the oak tree grows, it absorbs carbon dioxide from the air, trapping it without releasing it back into the environment, thus “cleaning” the air around it.
This property of trapping carbon dioxide is given by a natural coating that the bark of the oak tree possesses, which by the way has another practical use since this coating has a thermal insulating function.
This makes the constructions based on this wood retain heat better and consequently, the energy costs associated with heating can be reduced.
Therefore, we can say that green oak wood can reduce the carbon footprint of a building.
Low environmental impact
Finally, keep in mind that since green oak wood does not require any treatment, its use minimizes the production of by-products that are harmful to the environment.
In addition, due to the great natural resistance of this wood, there is no need to use chemical preservatives or pesticides that can seriously alter the environmental balance.
Keep in mind that these insecticides are often applied directly on the plantations, and although the presence of fungi or xylophagous insects (wood-eating insects) is negative in a carpentry shop, in nature these insects play an important role because they decompose rotten trunks and help control weeds.
That is why the use of pesticides can be harmful in environmental terms.
On the other hand, any leftover wood can be reused, whether in the production of sawdust, charcoal, or even biomass (another source of energy).
This is not the case with other woods, since chemical agents must be used to reuse them. As you have seen, green oak wood is an excellent quality alternative that can save you time and money, and at the same time that it favors the reduction of the environmental impact of the constructions in which it is used.