Traditional Materials are Naturally Antiseptic

Part 4 in the series, Can Beauty Kill Germs? Well-being, Immunology, and Traditional Building Materials.

The 120-year old reds, ochers, and creams of the

town hall of Schwyz, Switzerland are still bright.

It is fairly well-established that well-being and its violations affect our immune system. With
immunity tuned by life style variables like sleep, nutrition, obesity, and exercise, but also by emotions, personality, and social status, it is fair to extrapolate that the design of the built environment can also have measurable impacts.

Parallel to growing interest in holistic traditional Eastern practices which are being utilized as measures for healthier lifestyles, Western traditions such as classical music and painting—but especially traditional architecture and urbanism—are being found to have similar holistic impacts.

Knowing what we already know about Covid-19, we understand that pedestrian-centric urbanism and traditional environments that recapture indoor–outdoor relationships may be key to overcoming it. We understand the need for good indoor air quality, and reducing contaminants such as molds and bacteria. But the materials of modern furniture, flooring, coatings, paints, adhesives, sealants, wall coverings, textiles, insulation, and cleaning products seem to not only stress our well-being. They may be putting our immune systems at risk.

As discussed in The Art of Classic Planning, the standards of traditional design are holistic. They build on the structural sustainability of traditional materials such as stone, brick, stucco, and wood, their low carbon footprints, their antiseptic and other health benefits, and the social value of the presence of the skilled labor needed to build them.

Well-building materials include granite, sandstone, limestone, and marble, but also wood, brick, stucco, and glass, with a modicum of cast iron, steel, and unreinforced concrete; copper for roofing and flashing, and bronze for non-structural exposed metal elements. Metals should not appear on more than 5 percent of necessarily exposed structures—probably less. Masonry is preferable for exterior wall construction, and stone or glazed terra-cotta for building façades. For its durability, cast iron should be reexamined as a viable construction material. [1]

Obviously, traditional well-building elements contribute to healthy building design, lowering the potential risk for people in quarantine. Well-building ensures indoor environmental benefits such as good air quality through natural ventilation, low chemical emission materials, and wall sections that minimize moisture retention and mold growth. A three-wythe thick brick wall will not pass water all the way to the building interior. Nor will it harbor mold.

The selection of low-emitting consumer products, furnishings, and appliances is a primary control measure for achieving good indoor air quality. But the longevity of well-built buildings may bring long term benefits such as enhanced health and well-being can bring, includes greater individual and societal resiliency, and lower healthcare costs.

Outstanding examples of this include the antiseptic and antibacterial properties of wood and lime, and of the health benefits of the surfaces of natural materials—even polished—over that of metal and plastic, on account of their natural porosity. The Nordic Wood Project, which compared the hygienic properties of wood, plastic, and steel, showed oak as having the highest antibacterial performance, followed by beech, ash, pine, and spruce. Bacteria survived longest on plastic followed by stainless steel.

A partial palette of sustainable building materials (a) granite (b) sandstone (c) limestone (d) marble

(e) brick (f) terra cotta (g) glazed terra-cotta (h) stucco (i) wood (j) glass (k) cast iron (l) steel

Another example is lime. The sixth most mined material in the world, lime is used in nearly every industry. For thousands of years it has been essential in construction, being used in mortars, paints, antimicrobial coatings, adhesives, plaster, and stucco.

Limewash, a.k.a. whitewash, is a durable and antimicrobial finish for both interior and exterior use on masonry and wood. On metal it can stop rust. Its antimicrobial properties to this day provide hygienic and sanitary benefits for dairy structures. Salt can be added to prevent mold.

Notably, an even more durable finish for exterior use is mineral silicate paint the lifetime of which exceeds one hundred years. Buildings such as the White House, Buckingham Palace, the Sydney Opera House, and the Bolshoi Theatre are painted with such paints.

The town hall of Schwyz, Switzerland, illustrated here, received its coat of mineral paint in 1891. Plastic is generally not a building material and should likely be avoided. Contributing to that argument is the performance of synthetic paints which may be inappropriate for extended use.

[1] The term “well-building” is a technical, Vitruvian classical design term that bears no relation to any for-profit or non-profit organizations, or certifications issued by them, that use that term or others similar to it.


Contributed by © Nir Buras, 200423 v.20