Development of a clay - buildingboard with a surface ready to paint

Development of a building board consisting of a wood fibre board, coated with clay-plaster reinforced by natural plant-fibres (BioFaserLehm) for reinforcing planking of timber-constructions and also for statical not stressed inner wall surfaces.

Content Description




Because ecological wood materials will play a growing important part in building business in future the development of a building board from wood and clay was obvious, a board which combines the components wood and clay in an ideal way.

The technology consists of a board from wood materials which are coated with BioFaserLehm (a mixture based on clay plaster reinforced with natural plant fibres like hemp). After drying a surface ready to paint comes into beeing.

Unlike all the clay building boards available on the market, which have to be reinforced in a wet process and coated with a full layer of clay finish plaster on the building site, these boards shall be in possession of a "ready" surface.

With a board from wood material as support the building board can also be used as statical effective component and therefore fulfills an economic promising double function.

Fire resistance tests with similar compound fibre-clay plasters on timber constructions let expect far better fire resistance - properties for clay building boards than for gypsum building boards.

The technical challenge is the development and testing of an optimal clay-biofibre material and a bearing wood material structure which can withstand the stress of single sided coating with the clay work material BioFaserLehm and the occuring stress when buildt in.

Pretreatment of the statical stressable supporting board for optimal adhesion of the coating is an important factor for the amount of work and therefore an important criterion for reaching the desired better competitive product-price with the gypsum building boards on the market .

Beyond it the project deals with the development of a prototype of a coating machine which shall be able to create the above mentioned ready to paint surface and which is necessary for realization of this technical demanding project.

Furthermore the research, necessary for the project aims at the testing of different drying cycle times and -temperatures.

This shall be achieved by adapting wood drying chambers as beeing on the market by applying a technic of steering and regulation adjusted to preservation of the material characteristics of clay.

Extensive practically oriented investigations at test building sites and at testing laboratories provide and complete the necessary knowledge about the characteristics of the material for introduction on market.

By development of the wood-bio fibre building board a new constructional and ecological impeccable product comes into beeing which offers modern timber construction new chances on market.

The natur&lehm company in charge of development of the fibre-clay coating on principle does not work with chemical stabilized imitations of clay building materials as they can be found in market frequently.

Because only natural clean, true clay building materials can produce the best results on indoor climate compared with all other known building materials.

The clay building board shall be certified with a full declaration of material contents according to the new european "baubiologie" certificate "nature plus" for organic architecture materials.

Between the relatively expensive (overall costs) and technical not satisfactory clay -building boards and the cheap but from the point of view of organic architecture ("baubiologie") not quite satisfactory gypsum building boards there is an opening in the market.

Because of that chances for export into the whole EU - countries can result.

Sale shall follow the existing ways of distribution for ready mix clay plaster.

With the new product also in big cities the sphere.of interior fittings and redevelopment can be served more efficient which was up to now only insufficiently served by wet clay building methods.

With the prospect of the enlargement of the EU and the resulting economic and ecologic challenge out of it, the wood-bio fibre building board would be a good possibility to contribute to the aim of CO2 reduction. Because the product is suitable for do it yourself without vast technical effort or time consuming training also in these economical disadvantaged countries ecological building is possible and first of all affordable.

Project Partners

Project manager: Ing. Erich Longin
Fa. Holzbau Willibald Longin GmbH
Project partner:

Roland Meingast
natur&lehm Lehmbaustoffe GmbH


Ing. Erich Longin,
Fa. Holzbau Willibald Longin GmbH.
Siedlungsgasse 4
A-3843 Dobersberg
Tel.: 02843/2243/13