ISABEL RUBIO ARROYO | Tungsteno
Can construction materials and paints prevent the spread of COVID-19? Beyond the simple recommendations of open spaces, social distancing and contact with nature, there are still concerns about how the virus spreads through contact with surfaces. A study in The New England Journal of Medicine found that SARS-CoV-2 can survive for two to three days on plastics and stainless steel —mostly in healthcare facilities or even offices— and remain active on cardboard for up to 24 hours. However, other materials such as copper and its alloys (bronze or brass) are antimicrobial and also render viruses such as COVID-19 inactive in less than 24 hours.
Low-porosity, non-fibrous materials can help limit the survival of the virus. In fact, antimicrobial coatings are commonly used to remove viruses from doorknobs, countertops or walls. There is a rapidly growing industry that includes everything from paints with aggregates to kill microbes to coatings that harness other chemical capabilities. This is the case with silicon-based nano-coatings (organosilanes or silanes), which are polymer compounds that form a highly abrasive surface for viruses and bacteria. Other strategies take advantage of photocalytic qualities —activation in the presence of light— to try to eliminate bacteria that survive on surfaces and cause other infections. In the case of the coronavirus, some hotel chains in the United States offer rooms painted with anti-COVID material of this type.
But further studies are needed to determine to what extent these materials can be effective against the coronavirus. For the time being, the focus has been on synthetic compounds such as acrylic stone, a non-porous material popular for its antibacterial properties, its resistance to fire or to acids and solvents. Some examples are Hi-Macs, an acrylic-stone building material for facades that is supposed to be effective against viruses and bacteria, or Activ’Air. In the latter example, these are continuous ceilings made of an aerated gypsum core laminated on both sides with a special material that supposedly can improve the quality of indoor air. This is also the aim of Airlite paint, which, according to its manufacturer, will also eliminate micro-organisms from painted surfaces.
The need to maintain safety distances and establish protection barriers has led to the use of acrylic components such as Plexiglas, effective to stop infections but difficult to recycle. Credit: Actiu.
Better ventilated buildings
Beyond construction materials, the pandemic is also going to have an impact on the way new buildings are designed, from the promotion of modular construction to the greater compartmentalisation of rooms in order to provide spaces that guarantee social distancing between people. Various studies have indicated that the risk of coronavirus infection increases in closed spaces; for example, this "pre-published" work (yet to be peer-reviewed) concludes that the risk in closed environments is up to 18 times greater than in open spaces. Achieving proper ventilation in shops, hotels, offices, restaurants and schools has also become a challenge for the construction sector, tasked with minimising the viral load that could circulate in the environment.
In fact, the Federation of European Heating, Ventilation and Air Conditioning (REHVA) recommends avoiding air recirculation and ensuring the ventilation of spaces with outside air. Large windows with the capacity to open can improve natural ventilation, although their effectiveness can vary depending on the design of the building, its orientation, whether it has obstacles around it or the size of the spaces.
Signage and fixtures
The distribution of space is one of the key elements when it comes to finding solutions to minimise infections. In addition to increasing signage to ensure that the public respects the recommendations of health authorities, some companies such as Cushman & Wakefield propose removing or reorganising furniture and fixtures to maintain social distancing and avoid crowding.
Nuria Hornos, manager of IDEA Integración de Estructuras Arquitectónicas, suggests also using protectors and partitions in customer service counters made of non-porous materials such as glass or plastics such as methacrylate or polycarbonate. This helps to reduce the risk of the transmission of the coronavirus through the droplets we launch into the air when we cough or speak.
The need to incorporate protective barriers has, in fact, led to an upsurge in the consumption of these acrylic components such as Plexiglas during the pandemic, increasing demand and doubling the sales of the main producers. But adding more protective layers has its downside too, as they degrade slowly and are difficult to recycle.
Solutions to minimise the threat of infection in common areas such as bathrooms, lunchrooms or elevators, where it can be difficult not to press buttons, open taps or turn handles, are achieved through automation. Manufacturers such as Sacyr suggest installing taps equipped with a detection system that open and close automatically or are controlled by pedals; smart urinals; and automatic doors, soap dispensers and hand dryers. They also propose using photocatalytic paints, which eliminate organic and harmful compounds in the environment, or installing disinfection equipment using ultraviolet rays emitted by LEDs. This light, which is not recommended for homes because it can be dangerous to use, can be employed to disinfect certain types of surfaces.
The automation of mechanisms to avoid contact with surfaces and the use of synthetic antibacterial compounds help keep common areas free of contagion. Credit: Ecotap.
An uncertain future
It is still too early to know with certainty what effect the global state of alert generated by COVID-19 will have on the construction sector. The Catalan Institute of Construction Technology (ITeC) indicates that a decrease in the sector above 10% in 2020 cannot be ruled out. We will have to wait and see if the predictions come true. Regardless, the sector will have to adapt to the new normal and make the necessary changes. A report by the consultancy firm McKinsey indicates that the strategies to be followed in the sector if it is to emerge stronger from this crisis include digitalisation, investing in innovation and committing to energy efficiency, in line with the principles of the circular economy.
What is clear is that this is a sector that has a fundamental role to play both in the return to normality and in the evolution of the pandemic. The experience of the COVID-19 crisis has provided us with meaningful information to predict what post-pandemic architecture and urban planning should look like. As Naglaa A. Megaheda and Ehab M. Ghoneimb stress in their article published in the National Center for Biotechnology Information (NCBI), there is a need to use healthy planning and design strategies more effectively to deal with pandemics. The goal of creating more sustainable architecture and urban planning thus takes on a new dimension.
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Tungsteno is a journalism laboratory to scan the essence of innovation. Devised by Materia Publicaciones Científicas for Sacyr’s blog.