Fast aging of wood

Location: Ljubljana, Slovenia

Contact: Mr Boštjan Lesar and Mr Miha Humar

Tel: +386 1 3203 639


Estimated value: Other


The use of wood in the last years increase especially in segment of outdoor use (façade coverings, garden furniture, fences …). In such conditions, the wood is exposed to different weather conditions, which causes that the wood colour turn to grey. The surface of the wood is exposed to several factors that cause visual changes on the surface of the wood, this reflect as changes in colour and relief surface. The rain washed out, the decomposition products from the wood. Cellulose fibers remain on the surface, giving the wood a light grey colour. Wood begins to change colour immediately after outdoor exposure, but the process can take several years. Aging processes can vary greatly depending on exposure. Parts of wood that are not exposed to wetting, e.g. under abandonment, they are much less exposed, so aging processes are much slower. This causes very uneven colour changes in the wood, which disturbs the overall aesthetic appearance of the object or product. Our innovation in accelerated greying solves the problem of uneven colour change of wood exposed to the weather. By treating the wood with an aqueous solution of iron (II) sulphate, the wood colour turns to grey and the natural texture of the wood is preserved. So far, the solution has been used only for surface treatment of tannin-rich wood species. The reaction of iron ions from the solution with tannins darkens the surface of the wood (different dark shades of brown, black, grey and blue). We used iron ions to treat spruce and larch wood, the wood species most commonly used to make exterior wood claddings and do not contain tannins. Wood treated with an iron ion solution is greyed out immediately after treatment to prevent discoloration during the life of the object or product. Namely, wood soon after processing has a similar shade of colour as wood after several years of exposure to weather factors, thus avoiding different coloured shades of exposed wood. Which means that the use of iron ions can prevent the undesired discolorations of the wooden claddings objects. Iron ion- solution is water based, easy to use and environment friendly. The work with solution is ease and all the classical coating process (brushing, spraying and immersion) can be used. Only one application is needed. Treated wood dries quickly, which also enables rapid further processing and installation.

Benefits for investitor

Competitive solutions to the proposed innovation are surface coatings. Surface coatings offer good protection at the beginning of exposure, and after a certain period of outdoor exposure, coatings need to be restored. Poorly maintained or damaged coatings can adversely affect the service life of the wood. Sufficient treatment of the already installed façade cladding, flooring, etc. it is difficult to do as these are large and difficult to access areas. The price for re coating is also relatively high. While the proposed solution of treatment of wood with iron ion-based solution requires only a one treatment before installation, then the wood is allowed to age naturally. Surface of treated wood is not closed, so after wetting it also dries easily. This also gives a longer service life compared to poorly maintained surface coatings. 


An investment in our innovation would be beneficial because the investor would gain the know-how of manufacturing and using an innovative product with high added value. An investor could sell a treatment solution for rapid greying of the wood on the market, but it would also be possible to sell treated wood intended for external use (eg. claddings). Now increase the use of wood and the environmental awareness, so we believe that innovation has great market potential.


The advantage for the potential investor is that he / she will gain know-how of production and use of an innovative product with high added value. This is also a key opportunity for an investor to take the opportunity to be the first to market with such a product. We believe that with increasing environmental awareness of consumers, this is a great market opportunity. The production of an innovative wood-greying solution is cost-effective and has high added value. A potential investor could market the eco-friendly product on its own in consumer goods or sell it to wood 

carpenters who would treat wood for outdoor use (facades, cladings, fences, etc.) with an innovative product and sell it on the market.

Investment value

 For the final development of the solution and additional testing, we estimate that we need another € 150,000.

Desired form of investment and possible conditions

Investment in the research and development of the innovative solution, giving the investor the know-how of the final formulation of the preparation suitable for sale on the market. The condition is that the investor, in agreement with the researcher, authorizes the publication of research results in the form of scientific articles. The researcher and the investor shall agree on the amount of information disclosed on an ongoing basis.


Development strategy

This investment opportunity pursues the 3 objectives identified in the Slovenia’s 2030 Development Strategy. These are Objective 5: Economic stability, Objective 8: Low carbon and circular economy and Objective 9: Sustainable management of natural resources. The investment opportunity in the organic woodworking product is mainly supported by the 8th and 9th objectives of the strategy. The use of timber obtained in a sustainable way, however, represents a major contribution to the low carbon circular economy. Treated wood with such preparations is significantly less harmful to the environment than coating surface treated wood. Because the product allows the wood to get wet and dries also quickly when is properly installed. It can achieve long service life of such products, which further contributes to the low-carbon society. Being manufactured in Slovenia also contributes to economic stability (Objective 5).


Below, for each item, is stated how the investment opportunity meets the following objectives:

  • traceability and origin of the timber used from legitimate sources; not relevant to the specific investment opportunity
  • renewable energy source; in the production renewable energy is used
  • efficient use of resources; By treating wood with a solution for greying, you can achieve a longer service life and thus strive for efficient use of resources
  • prevention and reduction of waste generation; Minimal waste generation occurs in the production of the solution and the treatment of wood, the residues can be used as a source of energy from renewable sources.
  • estimated number of direct and indirect new green jobs due to the investment (estimate). We expect 2 to 5 jobs depending on the quantities produced and the production rate, or whether in addition to the production of the organic product, wood processing by the manufacturer is also provided.

Forest-timber chain activity

Wood working and processing.

Type of investment

Development of developmental and technical-technological solutions in the priority area of ​​application of the smart specialization “Smart Buildings and Home with a Wood Chain” (smart houses, furniture, etc.),

a solution to improve the relevant characteristics of native wood species,

development of solutions that will enable environmentally friendly and safe timber construction.