Natural Plasters: The What And The Why
Updated: Oct 20, 2022
What is a Natural Plaster?
A Natural Plaster is an ecological indoor wall covering between 2mm and 2cm in thickness made from natural materials (primarily clay or lime and sand, sometimes using natural plant fibers such as straw) that can be applied to almost any wall surface and finished with various techniques to produce a wide array of desirable and unique appearances. A Natural Plaster has a substantially lower embodied energy (the total energy consumed in the production of a material) as compared to conventional wall finishes (such as cement-based plasters finished with acrylic paints), is completely non-toxic, and improves indoor air quality and comfort by maintaining a stable indoor air humidity and providing thermal and acoustic insulation. Natural Plasters provide a unique opportunity to incorporate local materials to create a story that reflects the values and aspirations of the inhabitants and the particular place where the building is located. This is especially true in the case of a Clay Plaster, which can be made using the soil on site, provided that it has an appropriate amount of clay in its composition.
Do you want to be a part of the solution? Do you want to create something beautiful, ecological and unique in your home? I’m here for that conversation. Please get in touch and let’s talk about how we can Bring the Earth Inside.
Why Use A Natural Plaster?
Indoor Air Quality
Natural Plasters “breathe.” The permeability and hydrophyllic (water-loving) nature of clay and lime allow the plaster to absorb excess humidity from the air, store it inside its matrix, and later release that moisture back into the space when the indoor air humidity drops. Often when a space feels chilly or overly hot, what we are feeling is excessive or insufficient ambient moisture, respectively. A Natural Plaster’s capacity to hold and release moisture helps to regulate and stabilize the ambient temperature of a space. This “breathability” also helps to prevent the growth of mold and mildew associated with stagnant excess moisture in living spaces. Lime Plasters are especially mold-resistant due to their highly basic nature (pH).
Natural Plasters are derived from nature and are non-toxic. They contain no acrylics or other synthetic chemical components. Human beings are spending more and more time indoors in buildings that are more tightly sealed. Modern structures are built, finished, and maintained with many synthetic products whose adverse human health effects are starting to be better understood and quantified. “Sick Building Syndrome” refers to the phenomenon of people becoming ill from stagnant, poor-quality indoor air. The effects of SBS include respiratory illness, skin irritation, and increased levels of stress.
A building finished with natural materials like clay or lime greatly diminishes our exposure to conventional building materials and their subtle or acute effects on our health.
Low Embodied Energy
The ingredients for making Clay and Lime Plasters can be sourced locally almost anywhere in the world and require limited (or in some cases zero, in the case of clay soil) mechanical processing as compared to conventional materials. This means that the production and distribution of Natural Plasters uses far less electrical and fossil fuel energy and thereby creates substantially less carbon pollution than conventional materials.
At the end of a building’s life or when a building undergoes remodeling, Clay and Lime Plasters can be removed and returned to the earth since they are derived entirely of unadulterated earth materials. In the case of clay, the material just becomes re-incorporated into the soil surrounding the building. In the case of lime, the material breaks down into aggregate particles. Conventional building materials such as cement plasters and synthetic paints become ecological liabilities at the end of their useful life. How to safely dispose of synthetic building materials over the long term is an unsolved problem.
Natural Plasters can be made in an incredible array of colors using earth pigments or the natural color of the area in the case of a clay plaster. An incredible array of textures can also be achieved by employing different ingredients (sands and fibers), application tools, and finishing techniques. The plasticity of clay encourages the shaping of artistic, organic forms. Curved corners, niches and even sculptures integrated into walls are just some of the possibilities.
Walls finished with Natural Plasters have a story to tell. They connect us with the traditions of our ancestors who created shelter out of the materials they could find at or near the building site. With Clay Plasters we can create stunning walls from the soil immediately outside our homes. We can also look to incorporate local plant fibers into our walls. In the urban environment, the most accessible plant fiber is used paper. We can incorporate used paper into our plaster, preserving the drawings of our children or our personal writings into our walls.
Hard to quantify but equally hard to ignore is the sense of well-being evoked by Natural Plasters in a living space. Unlike painted surfaces, Natural Plasters have dynamic colors and textures and their sands play off of light sources, shining and shimmering in response to light sources or the viewer’s position in relation to the wall.
There is evidence that proximity to the natural world reduces stress and heightens happiness. Natural Plasters give us a great opportunity to Bring the Earth Inside.
Mano de Barro Natural Building and Natural Plastering encourages client involvement in the design process and also can involve clients in the application process should they be interested. Additionally, Mano de Barro can host workshops on the sourcing, mixing, and application of Natural Plasters that offset building costs and strengthen community.
Mano De Barro is a natural plaster company specialising in consultation and application of unique natural, ecological finishes of lime, clay and Tadelakt. Also offering educational workshops and complete construction using Natural Building methods, Mano De Barro is based in the Marina Alta, Costa Blanca region of Valencia and Alicante and serves the local communities of Javea, Moraira, Benitachell, Teulada, Marina Baixa and across Spain and Europe.
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