Green oak wood is now well established as the material of choice for many joiners for a wide variety of projects. It is the most commonly used timber for wood framed buildings and other construction jobs but has a wealth of uses beyond this. Due to its ease of use, green oak is a versatile material suited to large or small projects with few drawbacks. Before working with green oak for your latest job, it is worth weighing up the pros and cons and these will be discussed below.
Benefits of working with green oak
It can cost less than you think
Green oak (also known as freshly sawn oak) has not been dried or treated with preservatives of any kind. All of these processes will drive up the price of timber, as the time, energy or chemicals involved all come at a price. The unseasoned nature of green oak makes it a far more economical choice compared to treated timber. For larger projects, cost is always a concern and the lower the cost of materials, the better. Due to the natural strength and hardiness of oak, seasoning is not necessary for many applications.
It’s easy to cut and shape
As oak dries and loses moisture, it hardness increases. This can make dried oak extremely difficult to work with without industrial tools or machinery. For many users this makes dried oak prohibitive as they don’t possess the correct tools or find hire costs excessive. Due to its softness, green oak is far easier to work with and easy to cut or shape without specialist equipment. This even makes green oak furniture easy to build for an attractive and sturdy end product.
Kiln dried or air dried oak timber is cut to a variety of sizes before drying. Along with the shrinkage the drying process causes, this means finding particularly long pieces can be difficult. If the required size is not in stock, this can lead to a long wait until it becomes available again. Green oak can be cut to any size as and when needed and will be available immediately, avoiding delays. It is also easy to cut into decorative shapes for specific finishes and again this can keep costs down as less time and work is involved.
Resistance to damage
For hundreds of years, building with green oak has been a staple of British construction. Many of these structures are still standing in good condition, a testament to the longevity of oak structures. An example of this would be the hammerbeam roof in Westminster Hall which has been in existence since 1398. As green oak dries, it loses moisture and becomes extremely resistant to reabsorption of water. Combined with the naturally occurring tannins in the wood itself, this makes it an unfavourable environment to pests. Fungal, bacterial and insect infestations are very rare and in some cases, oak is actively poisonous to pests. Even in the damp British climate the water resistance of oak means rotting is rarely an issue.
Oak is lightweight and strong
Oak is a naturally dense wood, giving it a strength to weight ratio superior to steel. This gives it excellent load bearing capabilities as a structural component. Along with its strength, oak is particularly light compared to manmade building materials. As a result, it is easier to transport and lift and speeds up work when erecting a structure. For example, green oak trusses are very popular as they are easier to install and will bear the weight of any roof. Along with the availability of the large timbers needed, this is a perfect example of green oak’s strengths.
Green oak has a beautiful, warm appearance, with a distinct grain. As it dries it will take on a natural silvered appearance outdoors, or a warm, honeyed look on interior surfaces. Its initial look can be preserved with waxing or chemical treatment, but many prefer the character of aged oak. This also means that if the consumer prefers the look of seasoned timber it will develop over time without a higher initial cost. For exterior work, even rough sawn oak has a distinct natural look that needs no decoration. Indoors, a floor of green oak boards or modern but natural planed oak beams can be particularly eye catching.
Whether you are planning to enhance your house with a green oak porch or the addition of green oak cladding, weatherproofing is unnecessary. The density of the timber and its natural tannins make it exceptionally waterproof and this will only improve over time. The British climate very rarely produces humidity levels that can affect oak, even green oak.
Green oak is one of the most environmentally friendly building materials available. When sourced from sustainable forestry projects, it is actually a carbon neutral product. Its production doesn’t require any treatment that creates polluting fumes or chemical by-products and the oak itself traps carbon within itself. Additionally, the insulating properties of oak can reduce energy consumption whether used as a frame or cladding.
Drawbacks of using green oak
As it ages and dries, green oak will experience some shrinkage and this must be accounted for. This must be incorporated into any design to prevent shrinkage affecting joints and weakening the structure. Green oak is unsuitable for door or window frames for this reason and dried oak or other timber should be substituted. As the wood shrinks it can cause glazing to crack or sticking doors and windows. However, if this addressed in the initial design it can be avoided.
In green oak structures, wooden tenon and mortise joints are traditionally used, as the oak itself is strong enough. If metal substitutes are used, mainly for aesthetic reasons, iron fittings should not be used. Iron will react with the moisture and tannins in the timber and cause unsightly staining, so metals such as brass or stainless steel should be employed instead.
Damage to tools
When working with green oak, if the tools used are not cleaned regularly, the moisture and chemicals present in the wood can react with the metal of the tools. This can cause corrosion, but if the user is aware of this and cleans them regularly it can be avoided.
At Hardwoods Group, we specialise in wholesale timber supply and can offer all grades of green and seasoned oak. We can supply green oak of all sizes, cut to your specifications, for whatever project you have in mind. Contact us with your requirements, or call to speak to our experienced, expert staff who will be happy to offer any advice you need.