A fine finish
Floor and wall finishes rival ceilings and partitions for the greatest use of a single material (by area) within an interior fit-out. Some of the most significant environmental gains can be won through careful consideration of the floor and wall surface treatments.
The launch of the Green Star SA Interiors rating tool sees products and applications that previously fell below the radar of new build certification systems, suddenly getting more attention. According to David Baggs, CEO of Global GreenTag, the greatest environmental shift in the market place has come from “the realisation by building owners and product manufacturers that they need to use robust third party certification systems to communicate their sustainability credentials to the marketplace”.
A certified product is able to present verified data on its environmental status – what many sustainability practitioners have come to think of as the product or building’s ‘nutritional information’. Beyond the assessment of alternatives for performance and aesthetic preferences, could installation, detailing or institutional practices have a significant or positive impact for the environment?
Reclaiming materials and design for disassembly
The intended lifespan of the fit-out is crucial to determining sustainability of a finish. “Commercial office spaces can have relatively short life-spans and churn regularly so the end-of-life issues are paramount,” explains Michelle Ludwig, senior green building consultant.
The type of building and fit-out will determine the expected lifespan of a floor or wall finish. On the shorter end of the scale – and the more common scenario – the typical fit-out lifespan is one to seven years for corporate and retail tenancies. Retail fit-outs have the shortest fit-out life-expectancy in what Andy Horn, principal architect at Eco Design Architects, dubs “a kind of set-building exercise”.
If disassembly is ignored, the impending waste generated will likely be sent straight to landfill. Evidence suggests designing for disassembly in this context makes sense, and indeed, there are increasing examples of knock-down furniture and demountable partitions. But what about floor and wall coverings?
Regarding indoor pollutants and impermanence, carpets can be installed using a sticky tab system such as TacTile by Interface. The benefits include negligible off-gassing of pollutants associated with adhesives, and individual carpet tiles can be replaced in areas affected by high-traffic incidences. Carpets can be cleanly removed, ready for re-use or recycling at the end of their lifespan.
It is also possible to install engineered-wood floorboards as a floating installation, but this may present other problems and is only suitable for smaller areas. “The floating method is perfectly fine for many retail settings, especially if there is only a five-year life-usage,” says Joseph Brom, specialist flooring installer of Village Timber Contractors.
To architect Wolf of Wolf & Wolf Architects, timber is a highly reclaimable material, because, being close to its natural state, it can be manipulated or remanufactured if it has been damaged. “Even relatively badly reclaimed or worn timber can be machined into a narrower plank,” he says. But to Brom, the limitation in specifying recycled timber is the availability of stock, as the loss of material in the machining process means reworked material can only go to applications requiring smaller areas of coverage.
On the other end of the life expectancy scale, public buildings, institutions and national monuments have an expected life of up to 100 years or more and a desired performance specification of “vandalproof” and “low-maintenance” finishes.
Stone, commercial-grade tiles, solid-wood and specialised screeds such as terrazzo or corkoleum are commonly used and meet the requirements for longevity. However, maintenance practices become paramount, as correct care could add years of use to the floor’s life.
A material with middling life-expectancy is linoleum, which can be put to service for 20-40 years. Many green building consultants favour it because it is anti-microbial and made from natural materials, including linseed oil and wood-dust. The latter can be reclaimed as a bi-product of other timber-manufacturing processes. But like all natural materials, including stone, wood, clay-tiles and even some screeds, it requires a sealant, and benefits from regular reapplication.
Modern sealant choices tend to be either polyurethane or natural oil-based. Floor sealant manufacturers, such as Bona, WOCA and Pronature, who offer natural oil alternatives, stress the importance of using appropriate floor cleaning products for routine maintenance to ensure the topcoat is not unnecessarily compromised.
Beyond daily cleaning, natural oil finishes need to be polished and replenished every one to three years and polyurethane sealants can similarly benefit from a deep clean and overcoat. Both practices reduce the requirement for complete refinishing, which in the case of a wood floor would involve sanding and would shorten the expected lifespan of the floor. It is possible to strip or scrub an oiled floor and never have to sand it down.
“The thing about floors is they get cleaned a lot, in fact the cleaning and maintenance of floors can often be the single largest life cycle impact, even outweighing the manufacturing stage sometimes,” says Baggs. He says that should floor technologies (such as ceramic tiles or sealers on vinyls and linoleums) develop to reduce cleaning, and especially stripping and resealing processes, this could create a massive reduction in life cycle impacts.
Where floors and wall-coverings are concerned, the Volatile Organic Compounds (VOCs) used as solvents to help paints, adhesives and sealants cure properly are an indoor pollutant and respiratory irritant of real concern to occupant health and wellbeing, emphasises Horn.
Horn says there are materials that can be used that don’t just reduce the negative impact on the internal environment, but can also provide a positive outcome both for the environment at large and for the internal environment. He cites linoleum as an example, which is anti-microbial and is a carbon sequester due its constituents of wood flour and cork dust.
To Horn, the most interesting material in this regard is clay plaster. “The main benefit is the ability of the plaster to buffer, or regulate, humidity and in this way the plaster can become a natural air-conditioner. Clay is the most permeable or hydroscopic,” says Horn, comparing it to lime. “Lime has antiseptic properties, and although it breathes and exchanges moisture, this is not as much as clay. Clay will typically maintain a humidity of 40%, which is best for respiratory health.”
Another innovative solution to green finishes, which has all the iconic credibility of being visibly green and bringing nature into the space, is the use of green walls. Paragon Interiors designed two living walls at TotalSA and Group M. Living walls typically have a higher moisture content than clay, but have the additional benefits of releasing oxygen and providing psychological benefits derived from a sense of connection to nature – even if in a limited form.
The art of using less
Herbert Groenewald of Lafarge notes that internationally, polished concrete or self-levelling screeds are ranked as the fifth most popular sustainable flooring product globally. This being said, it was mentioned by experts interviewed as “the most sustainable option” on the grounds that to use nothing, or omit the use of a resource, does less harm. “In my opinion it should rank first, as the top four flooring options are all installed on top of a concrete floor in any case,” Groenewald says.
Meanwhile, Baggs highlights the role that exposed thermal mass can play in passive building systems. “Floors can be a building’s connection to the thermal cooling and heating provided by slabs on ground or even elevated concrete slabs,” he says. “The inherent thermal mass of concrete – and especially concrete slabs – can provide tremendous passive thermal comfort and this can be negated or reduced if inappropriate insulating floor coverings are used.”
After exposed concrete, Horn, Ludwig and Wolf rank recycled or reclaimed materials as the next most sustainable flooring option. Within a market where quality reclaimed materials are in short supply, the next step on the rung is to install new materials that can be removed when the tenant has finished using them. This raises the question of what happens to the materials after they are reclaimed and how they reach the market.
To Ludwig there is an opportunity to rethink the ownership of the fit-out or its components, where a floor may be sold. This can take the form of a lease-agreement with a buy-back scheme when the tenant is finished with it. “I think there is much potential in lease-agreement structures for interior finishes, as has been implemented in other countries,” she says. “Essentially the occupants are renting the use of the carpet, for example, and benefits include moving the capital expense to the operating budget. It ends up costing about the same for the life-span, includes a maintenance contract, and the manufacturer is responsible for reclaiming and reprocessing the product at the end.
This does assume that the product has been initially designed to return and that the manufacturer has a recycling initiative in place.” This presents an interesting challenge to producers, contractors and the construction business to offer products that can be installed in ways that encourage material reclaim and to facilitate a takeback programme that sees the product recycled, or re-machined for use in secondary applications, and distributed to market.
By Peta Brom
The full article appears in the August-September 2015 earthworks magazine.