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Updating Clay

Denne idé er en del af The Circular Construction Challenge – Rethink Waste

Lasse Nielsen
7. oktober 2018

Egen Vinding og Datter (EVD) has worked with clay as a construction material through the last 15 years. Through these years EVD has run Lerstensfabrikken (The CEB-factory) where we produce unburnt, compressed earth blocks. In EVDs construction company we work with the bricks, make clay plaster, clay floors, light-clay insulation etc.

Generally clay as a construction material holds a very large potential for sustainable construction and circular economy, among other things as an alternative to very Co2-emitting materials as cement and hydraulic lime mortar. As clay materials are produced without burning the energy consumption in production is less than 1/20 of what goes to production of cement. The raw material is almost inexhaustible. In DK boulder clay is the most common surface near soil type. Clay has extremely good properties for indoor climate as it is a hygroscopic material, helping to balance the moisture content in the air, and it also helps ensuring a good ion-balance in the air. Clay also has unique properties regarding circular economy as the material can be directly reused without going through a new industrial process, or it can be given directly back to the soil. The material is also far better than lime and cement for the work environment as it is more gentle for skin and inhalation.

We want to develop the basis for three product lines. We think this is realistic in the time frame as there are big overlaps in their production form and as to how the development work, the documentation and tests will happen. Also, we are set for an intensive project period.

The products are based on Danish boulder clay and hill gravel. EVD already receives boulder clay from excavations by new building projects (from where it would be driven away anyway). The material is usually received from excavations so close, that it means a lowered consumption of transport. 

In this sense the boulder clay can be described as a waste product being upcycled to nobler materials, used inside buildings, with good indoor climate effects.

Clay Plaster Mortar is to be seen in comparison with cement or lime based plasters, but also with painted surfaces, as clay plaster has the advantage that it can be applied on many surfaces where you can't use a cement or lime based mortar, for instance on plaster boards or on painted surfaces. In comparison with other plaster materials, clay is superior in terms of Co2, resources, circularity, indoor climate and work environment. The material is after hardening somewhat softer than other plaster materials. For this reason it's important to make an optimised material with as great strength as possible.

Light Clay Blocks should be seen in comparison with gas concrete, wood fiber boards, cork, and other materials that can be put up indoor without a skeleton and be finished with plaster. The clay blocks will perform well in terms of Co2 and resources, but compared with wood fiber and cork boards they won't necessarily have better properties in terms of indoor climate and work environment, but also not worse. The blocks will be good for additional insulation of masoned buildings indoors, and particularly good for timberframe houses.

Clay Floors should mostly be seen in comparison with concrete floors, as they give opportunity to make a solid floor build-up with a great thermal capacity. But the clay floor is superior to the concrete floor on all environmental parameters og particularly concerning energy consumption/Co2-emission in production and in terms of recycling, the difference is very big.

The goal of this project is to remove barriers so the materials will be easier to use, especially in professional construction where the greatest potential lies, but also for DIY-people.

The Finish Layer for Clay Floors is probably the most revolutionary, as it is now quite complicated to make the material on site, and because we assume that we will be able to offer a far wider color spectrum, than what has been possible till now. So this product we will be able to develop into a whole color series. We see a very big business potential in this, as there is a hastily rising number of people who wish to live with clay floors. This material also has a greater international potential than the two other main products, as we can only find one example of a similar product, and that one isn't optimal. Here we have a possibility of playing into the German market, where we have a good partner. 

We already sell quite some clay for customers' own mixing of Clay Plaster Mortar. It happens that the customers have a bad experience of not managing to make the right mix. We think it can do a lot of good if we can make a material that is readymade and easy to use and delivered in both big-bags and 25 kg bags or buckets of a nice design. Hopefully this will make it easier to get it onto the shelves of paint shops and construction markets.

Regarding the Light Clay Blocks there is a big market for materials for indoor additional insulation. The key to their market potential will be that they are easy to use and cheap.

From EVDs side the steering group consist of Lasse Koefoed Nielsen, Per Sørensen og Lars Koefoed Jørgensen. Lasse Koefoed Nielsen is project manager, Per Sørensen focuses on the product development. Lars Koefoed Jørgensen ensures the connection to the entire strategy of EVD. We are well covered on the technical side of the project. But we could benefit from external competences in order to unfold the business potentials of the products.