An in-depth insight into everything there is to know about timber and bamboo flooring and how they excel in terms of sustainability.
Before delving head first into the natural beauty of wood and bamboo, perhaps one should first question the true meaning of the word ‘sustainable’. Originally put forward by the Brundtland Commission, a now-common definition of sustainability is “meeting the needs of the present without compromising the ability of future generations to meet their needs”.
However, when looking at sustainable, eco-friendly floors, a few questions arise that need to be answered:
1. Were the raw materials extracted in such a manner that they did not degrade natural habitats?
2. Did the energy used in manufacturing and transporting the product cause as little ecological damage as possible?
3. Were the scrap and waste materials recycled or re-used?
Affirmative answers here, along with the definition above, should be a good indicator of what is referred to when speaking of a sustainable flooring product – in this case, wood and bamboo. As a material, wood is inherently “green”. Besides being renewable, wood is non-toxic, energy-efficient to grow and manufacture, as well as recyclable and biodegradable. It is considered the only building material whose production yields life-sustaining oxygen and absorbs the main agent of global warming, carbon dioxide.
Wood can be a truly sustainable resource. However, to realise that potential, it has to be sourced and produced responsibly. Eco-friendly wood can come from salvaged, reclaimed and recycled sources, or it can come from ecologically well-maintained forests and plantations.
As wood and bamboo are both natural products that are derived from natural plant elements, the question arises, bamboo or wood? As bamboo grows much faster than trees, it is an excellent flooring choice for those looking for more sustainable flooring options; however, the idea that bamboo is the more environment-friendly option is considered by many to be an oversimplification.
Sustainably harvested wood does push the timber industry in a more positive direction by discouraging illegal logging and helping to create economic value for a forest ecosystem, which is why harvested wood is seen as a more proactive environmental choice. But again, these opinions hold sway both ways, with some either supporting or disagreeing with the choice of bamboo over wood and vice versa.
A quick characteristic definition of hardwoods and softwoods
These words are loosely used to encapsulate characteristics that do not necessarily apply to a specific timber so, for the sake of clarity, let’s define these two wood types more intently. Hardwoods are derived from broad leaf (deciduous) trees and most are harder than softwoods, but there are exceptions. Many people believe that the stability of a particular type of wood (the amount that it expands or contracts in response to humidity changes) relates to its hardness, assuming that harder woods are more stable. In fact, stability and hardness are not related, and some of the hardest woods are the least stable, while some of the softer woods are extremely stable.
Solid wood flooring is milled from lumber and each plank is a single piece of wood throughout its thickness and width. The wider the board the more susceptible it is to expansion and contraction. This means wide-plank floors develop gaps more quickly under dry conditions and cupping or buckling under wet conditions than wood floors with narrower planks. If one’s preference is for wide-plank flooring then the engineered option is advisable due to its greater stability.
Engineered wood flooring
Unlike solid wood flooring, engineered wood flooring comprises multiple layers and components. All types of engineered wood flooring have two basic components. The first is a wear layer or surface layer. This is the wood that is seen and walked on in the installed floor and therefore typically gives the product its name. The second component is a substrate, or the platform that supports the wear layer, which can be made up of various materials or layers.
Solid versus engineered wood
Both of these floor types have a unique place in the marketplace. Each has its appropriate application depending on project conditions and needs, and customer priorities. That being said, there are still a number of myths surrounding engineered wooden flooring. Solid wood flooring is considered by some to represent real quality in wood flooring, while engineered wood flooring is sometimes thought to be a cost-effective substitute for the real deal. While there are cheaper and low-quality engineered wood flooring products in the market, there are several flaws in this notion.
The great advantage of solid wood flooring is that solid wood planks almost always have a thicker wear surface, allowing for additional (ranging from three to five) sandings and refinishing. Most engineered wood floors allow for two to three sandings depending on the thickness of the wear layer, the hardness of the wood and the skill of the craftsmen.
Benefits of Engineered Flooring
• Cost – It is generally less expensive to install, especially when installed directly over a concrete subfloor.
• Stability – Due to its layered construction, engineered flooring expands and contracts less than solid wood flooring.
• Versatility – These floors can be floated over and glued to concrete and other non-wood subfloors as well as nailed or stapled down to wood subfloors.
• Environmentally friendly – Engineered Flooring gets a lot more ‘face’ veneers out of a tree than solid floorboards (2-6mm versus 18-25mm solid). The core of these floors is usually manufactured from renewable-resource wood species such as pine, poplar, eucalyptus or even rubberwood.
• Long lifespan –. Engineered floors have a 3mm-5mm top hardwood layer. High-quality engineered hardwood floors can be sanded and refinished five to eight times, extending their usable life to approximately 100 years. Products that use less than 2mm of hardwood typically cannot be sanded and refinished and may last approximately 10-15 years. Floating floors with a wood layer of 2mm or more can usually be sanded once or twice for a usable life of up to 25 years.
• Suitable for use under floor heating – The technology and increased stability of engineered hardwood floors make them an ideal choice for use over radiant heat (underfloor heating) systems. This allows for a more efficient heat transfer. The stabilising backing of multiple layers of plywood also helps to prevent the floors from undergoing excessive expansion and contraction caused by the heat transmission. Therefore, these floors remain flat and tight over time. Floating hardwood floors are also suitable for installation over radiant heating. These floors allow for expansion and contraction because they float. Furthermore, because they do not require a plywood subfloor, they also allow for good heat transmission.
Eco-friendly wood flooring installation
1. Nail- or staple-down method – Nailing or stapling to a plywood subfloor is relatively fast and inexpensive provided that there is already an acceptable substrate in place.
2. Floating method (engineered flooring) – The floating method is very fast and inexpensive. Flooring can be floated over all types of substrates, including wood, gyp-crete and concrete. With regular tongue-and-groove flooring, a bead of glue is applied to the grooves on the sides and ends of each piece of flooring which is then fitted to the tongue of the installed course. In situations where moisture is a concern, floating floors allow the installer to lay an impermeable moisture barrier between the subfloor and the flooring. In a floating installation, when planks expand and contract in response to humidity changes, they move together as a unit towards or away from the walls. This means that a properly installed floating floor will not develop gaps between the planks under dry conditions and is less likely to cup or buckle under moist conditions. Solid wood flooring cannot be floated as it expands and contracts much more than engineered flooring. Some engineered floors come with a click-together system.
3. Eco-friendly underlayment – These underlayments are useful for all types of subfloors and are excellent for floating installations over radiant heat systems. They often contain an antimicrobial agent that inhibits bacterial and fungal growth and the proliferation of dust and mites. They also reduce noise and floor-to-ceiling sound transmission while insulating cold floors.
4. Glue-down method – A glue-down installation involves applying wood flooring adhesive to the entire surface of the subfloor and then laying each piece of flooring directly into it. The resulting installation is quiet and feels more solid underfoot than a floating installation. It is important that only elasticised glues are used that expand and contract with the flooring.
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Care and Maintenance of Wood Floors
There is no such thing as a scratch-proof wood floor, but following these basic procedures will reduce the likelihood and frequency of scratches:
• Don’t allow people to wear spiked heels on the floor as these will damage even the hardest wood floors and finishes.
• Pet claws should be trimmed at all times.
• It is important to remove grit. Care should be taken to prevent dirt, sand and grit from accumulating on the surface of the floor as they will act as sandpaper and abrade the finish. Walk-off mats should be placed inside and at all exterior exits, and the floor should be dust-mopped with a micro-fibre mop and vacuumed frequently. Rugs should also be cleaned and replaced frequently.
• Always use proper cleaning products. To clean a floor with a factory-applied urethane finish, simple water with a damp mop is efficient in removing scuffs, dried spills and dust film, but for a more thorough cleaning look for a non-toxic cleaner specifically formulated for hardwood floors.
• Take care to avoid standing moisture. Water and wood floors do not mix. Never wet-mop a wood floor, and always clean up spills as soon as possible, never allowing them to stand. A damp mop is fine but only if the moisture will evaporate almost immediately. Do not allow soiled mats to stay on the floor as they can trap moisture on the surface.
Three eco-friendly wood pitfalls to avoid
1. Many wood flooring complaints and claims are as a result of conditions beyond the control of the manufacturer or seller of the product. It is important to educate oneself on the pitfalls to avoid. It is critical to avoid wet concrete slabs at the time of installation. Inadequately cured concrete slabs continue to release moisture after flooring is installed, causing movement and other problems for wood flooring. On- and below-ground-level concrete slabs can become wet if groundwater rises. Adequate curing times and proper moisture barriers are essential.
2. Improper heating and ventilation can cause problems. Most wood flooring is manufactured to perform best within relative humidity ranges of 35% to 60%. It is important to run heating and humidity control systems ahead of installing wood floors so that the site conditions at the time of installation are similar to those that will prevail when the space is occupied.
3. Conditions that are too dry can have the same effect as conditions that are too wet. Dry climates can present environmental conditions that are very hard on wood flooring. This is not just an issue with eco-flooring, it is an issue with any wood flooring from any source. Wood floors are products of nature, and as such are subject to natural forces. Engineered wooden flooring would, however, move less than solid wood flooring during these climatic changes.
Refinishing a wooden floor by means of screening and top coating
Screening and top coating is a method of renewing the finish on a wood floor without actually removing the old finish and sanding down the wood. It will remove most signs of wear and create a uniform, sealed surface on the floor. It is relatively quick and inexpensive and can be repeated indefinitely. With screening and top coating, even the thinnest wood veneer wear layer can last forever as people walk on the finish, not on the wood.
There are both mechanical and chemical systems for screening, i.e. roughing up the surface of the old finish so that the new top coats can adhere to it. The mechanical method usually involves putting a scotchbrite pad or 120/150 grit sandpaper on a standard drum flooring sander and operating the sander in the normal fashion.
Firstly, it should be noted that not all bamboo flooring is the same. Bamboo is a durable and attractive choice. It is rapidly renewable, growing to maturity in 5-7 years. It is sturdy and extremely hard. In addition, it is attractive and available in solid vertical, woven and engineered versions. It offers a variety of colours and grains and is cost-effective, often being less expensive than hardwood and just as easy to install.
The rise in popularity of bamboo as an eco-friendly flooring material has created a simultaneous surge in manufacturing capacity. There are a number of manufacturing variables that determine the ultimate quality of the bamboo flooring. These include processing time, moisture content, density level, the adhesives that are used to manufacture the end product and the quality of the surface coating.
Processing time is a critical factor and bamboo should be processed quickly after cutting otherwise it can develop surface mould that is often visible in the finished product. Top-quality manufacturers process their cut stalks immediately to eliminate this possibility.
Moisture content is also important and it is imperative that the drying process should be as long as possible at the time of manufacture. Moisture content can vary widely, from 7% to 14%, and many bamboo mills ship material that has only been dried to 9-12%, which is not adequate in many climatic regions. With woven bamboo, in particular, the drying process is essential. If woven bamboo is manufactured to 9-12% moisture content and then installed in a dry climatic area, it has a tendency to crack or develop ripples on the plank face. For installations in areas where relative humidity drops below 35%, material that has been well dried at the factory is essential.
As noted, the three most common styles in the marketplace are solid vertical, strand-woven and engineered bamboo flooring.
Solid vertical bamboo flooring
The construction of vertical bamboo gives a floor a very fine grained linear look. In this vertical style, the strips are turned on their sides and laminated together in long, slender rows, creating a vertical appearance. Vertical bamboo flooring often appeals to people looking for a typical bamboo look for their floors, something different to the traditional timber look that is typically found in the strand-woven varieties. In terms of hardness, although not as hard as strand-woven, solid vertical bamboo is still a very hardwearing and durable flooring material, comparable with hardwoods such as red oak.
Strand-Woven bamboo flooring
The strand-woven bamboo manufacturing process produces flooring that is twice as hard as traditional bamboo flooring, which is already a very hard wood floor. It is made with a non-toxic, water-resistant resin. While this method allows for use in kitchens and bathrooms, it needs to be noted that, like all hardwoods, it does need to be properly maintained, considering the fact that bamboo is not waterproof but water-resistant.
Engineered bamboo flooring
Due to the fact that it is laminated to a cross-ply backing, the top layer of an engineered bamboo floor doesn’t have the ability to shrink when the floor is exposed to dry air, which causes stresses to develop within the plank. Bamboo fibres are very strong, but the bonding material between them is weak, making engineered bamboo floors much more susceptible to surface checking (cracking) than most engineered hardwoods.
Reflecting on both timber and bamboo flooring in an in-depth manner enables one to make an informed decision on the type of flooring to select for unique specifications. This will ensure that the installation exceeds all expectations and lasts for the duration it is intended for.
Acknowledgement and thanks are given to https://system.netsuite.com (Eco friendly Flooring Guide and www); Bamboo Warehouse; FloorworX; Forest Flooring; and Wood Floors SA for the information contained in this article.