There are multiple misconceptions when it comes to recycled timber, especially in its terminology and modern myths surrounding recycled, reclaimed, upcycled, reused and refurbished. Everyone has a general idea about differences in softwoods, hardwoods, quality and finish, but when it comes to selecting the right timber for the job, amongst the confusion and deception, consumers are often lead down false trails. Even those in the building industry including architects and interior designers often neglect the inherent and sentimental qualities that a quality piece of recycled timber can bring.
So here are 8 easy steps that you need to know before purchasing your recycled timber:
STEP 1: KNOW YOUR TERMINOLOGY
When selecting timber, that subconscious voice in the back of our head, urging us to make an environmentally friendly choice, turns into headache as our eyes and ears are bombarded by apparently 'green' labels and claims that a specific product is supposedly more 'sustainable'. Have an understanding of what each of the following terms mean prior to purchase, and investigate/question where your timbers are sourced from:
- Recycled Timber: are those that were broken down by machine-processing to make an entirely new product. It is also used loosely to define wood that is salvaged and reused, essentially reclaimed timber
- Reclaimed Timber: is not broken down by machine processing and made into an altogether new product, but rather taken from its original location and repurposed for a new location. There are minimal changes to timber aside from length adjustments, sanding and refinishing
- Upcycled Timber: are pieces of timber that are old or have been discarded and processed into something to give it a better purpose, often to the same or better quality than the original
- Reused Timber: are pieces of timber that have been repurposed and not treatment applied at all
- Re-milled or Refurbished Timber: are pieces of timber that have been repurposed and given a new treatment or finish.
- Salvaged Timber: are pieces of timber that are taken from old projects and rescued from what would have otherwise been as waste
STEP 2: KNOW THE DIFFERENCE BETWEEN HARDWOODS & SOFTWOODS
Determining whether your project requires a hardwood or softwood now become very important as you now have a solid understanding of what each of the different recycled timber terms mean. Here are some benefits/negatives of using both types of wood:
- Hardwoods: have a slower natural growth rate, making them denser and more fire resistant than most softwoods. As such, hardwoods tend to be more expensive. Hardwoods are sometimes challenging to work with, but last for a great deal of time. They are typically used in high quality furniture, desks, flooring as well as some construction that needs to last. Consider using hardwoods in structural pieces such as apex beams where structural integrity is of high importance.
- Softwoods: have a faster natural growth rate, making them less dense and less fire resistant in comparison. As such, softwoods tend to be less expensive and make up the bulk (80%) of all timber used in the construction industry. Softwoods re easier to work with and typically used in windows, doors, furniture, paper and medium-density fibreboard. Consider using softwoods in timber scaffolding such as non load-bearing walls and roof rafters.
STEP 3: UNDERSTAND THE TIMBER VOCABULARY
Now you might have chosen a hardwood or softwood, but how come pieces of the same species are different in colour and price? Understanding which parts of the tree the timber comes from will help you understand these differences. Lets build up that vocabulary:
- Heartwood: usually darker in complexion and more dense. If your timber comes from this part of the tree, you may see some increased price differences between pieces of the same species. Heartwood is the part of the tree that is 'dead', meaning it has been matured and yields the hardest timber
- Sapwood: usually lighter in complexion and less dense. If your timber comes from this part of the tree, you may see some decreased prices in comparison to heartwood pieces. Sapwood is the 'living' part of the tree, as layers from the outside gradually become the inner layers which die and turn into heartwood
- Cambium Layer: differing from tree to tree, this layer is the tree's protective layer that produces the growth rings inside the tree
- Pith: is the centre of the tree which usually carries the tree's nutrients
STEP 4: KNOW WHAT CUTS YOU ARE GETTING
Whilst the different cuts of timber may have no direct impact on timber prices, when selecting timber for decorative or structural purposes, the orientation of the grain becomes extremely important as some cuts are likelier to bend or contain more imperfections such as knots than others:
When choosing timber for an aesthetic qualities, the general rule is that knots and cracks tend to increase toward the center of tree. So when a piece of timber is labelled as
- Clear Cut: these pieces have the fewest knots and are ideal for projects where knots and cracks are unwanted
- Centre Cut: these pieces tend to contain more knots and cracks, making them ideal for projects where a 'rustic' look is needed.
When choosing timber for structural qualities, the general rule is that the growth rings which have a higher degree to the surface of the board, tend to warp more when affected by water:
- Rift Sawn: these pieces have the growth rings 45 to 60 degrees to the surface of the board. They are usually toward the centre but differ from mill to mill, these pieces are usually cut thicker as thinner board may bend under watery conditions
- Quater Sawn: these pieces have the growth rings 60 to 90 degrees to the surface of the board. These pieces have a tendency to warp under watery conditions, but are ideal for furniture making such as bookcases or shelving
- Flat Sawn: these pieces have the growth rings 45 degrees or parallel to the surface of the board. These pieces produces an appealing aesthetic 'flame-like' effect where the growth rings radiate out from the centre
STEP 5: KNOW THE TIMBER GRADING SYSTEM
When it comes to grading each piece of timber, every tree is different from the other. Some may contain more burls than others whilst some are completely blemish-free. There are two main types of grading systems that are used to ensure quality control in the industry:
- Structural Grading: there are two different types of test used to determine a structural timber's strength and durability:
- Visual Stress Grade (S-Grades): is determined by a trained grader who looks at species, size, position of knots amongst other things. These grades are divided into seasoned and unseasoned timbers. The lower the number (e.g. S1) the higher the quality of the timber
- Mechanical Stress Grade (F-Grade): more widely used, especially in Australia, the strength and stiffness of the timber is determined by a bending test performed by a machine. The higher the number (e.g. F27) the higher the quality of the timber
- Aesthetic Grading: are used for timbers to determine the quality of a surfaces appearance. There are three aesthetic grades:
- Select: has the minimum number of knots, straight grained and uniform in appearance. Timber used in flooring are usually of this grade
- Standard: has a varied appearance from piece to piece that gives a distinctive appearance. Most timbers used for wood projects such as as shelving or bookcases are usually of this grade
- Character: has a 'rustic' appearance and characterised by knots, burls, cracks and sap streaks. Typically used in furniture such as table slab where a natural rustic look is required
STEP 6: KNOW THE DIFFERENT DRYING TECHNIQUES FOR TIMBER
How timber has been dried can have a big importance as some timber later on in life start to crack or bend. There are three types of drying techniques:
- Greenwood: is timber that has been recently cut and not had an opportunity to season (dry). The benefit of using greenwood is it is extremely easy to work with and split less when nailed or turned. The negative is that greenwood has a tendency to crack and warp once fully dried
- Air-Dried: is timber that has been stacked and placed on foundations and exposed to the air in a clean, cool, dry and shady place. Air-dried timber takes months even years to dry which is why they are usually more expensive. The benefit of using air-dried timber includes increase moisture stability meaning they tend to bow, twist and crack less.
- Kiln-Dried: is timber that has been artificially dried, using a heat generator. Kiln-dried timber dries much faster thus sawmills are able to turn-over timber at a faster rate. This results in a lower price. due to the nature of this fast-drying process, most insects and eggs living inside the wood are killed, but the wood tends to bow, twist and crack more
STEP 7: KNOW THE DIFFERENT CUTTING FINISHES
Once you have understood all the previous steps, now comes the easy part. Choosing how the timber is finished in the cutting machine will help you when measure out the precise measurements you may require for your particular project. In general:
- Live/Natural - Edge: are typically seen in stabs where the sides are left untouched to give a natural designer look. Whilst of the surface some leave holes and cracks which can be filled with resin
- Rough/Nominal Sawn: is timber that has come straight from the circular saw meaning the dimensions are only rough. The surfaces and edges are not smooth and the blade marks are still visible
- Planed/Dressed: is timber that has been passed through a thicknesser to the required dimensions, a process which ensures the edges are accurate and square whilst having a smooth surface to touch
- Surfaced: is timber that has been sanded to a 'polished' feel where the timber has been hand-sanded and ready for a finish such as oil or varnish
STEP 8: CHOOSING YOUR FINISH OR STAIN
With so many products on the market, how do you know which one is suitable for you? There are three types of finish that timber can be treated with:
- Evaporative: uses alcohol, acetone or waxes which create layers that will rebind upon each successive layer. Evaporative products requires multiple coats to each the desired 'sealed' or 'protective' effect. These products build upon the existing timber and only just penetrates the surface.
- Reactive: uses white spirits or oils as a base which require some scuff-sanding between layers. These products penetrate into the timber to achieve the desired coloured or sealed effect
- Coalescing: uses water as a base and usually only requiring one or two coats. Can be easily cleaned with water. These products penetrate into the timber to achieve the desired coloured or sealed effect.
Be careful of false advertising and claims that a product is more 'sustainable' or 'structurally' better, always choose products based on the information above and ensure what you want before going out to buy it.
THAT'S IT! YOU NOW HAVE ALL THE KNOWLEDGE YOU NEED TO MAKE AN INFORMED DECISION BEFORE GOING OUT AND BUYING RECYCLED TIMBER!!!