Mechanical and Fungicidal Properties of approximately 100 Years Old Oak, Beech and Spruce Wood Beams

The aim of this preliminary study was to investigate differences in mechanical and fungicidal properties of three different wood species (English oak (Quercus sp.), common beach (Fagus sylvatica) and Norway spruce (Picea abies)) specimens that were in indoor use for several decades, compared to control specimens of freshly cut timber. The collected material was cut to smaller specimen and conditioned in standard climate prior to further analysis. Mechanical, fungicidal, and sorption properties were determined according to the standard procedures. Our results show that mechanical properties of oak wood do not deteriorate in the investigated time frame. On the other hand, resistance of the wood against fungi decreases over time. The reason for this is yet to be confirmed, it could be due to the degradation of secondary metabolites. Similar results were observed for spruce wood as well. There were no statistically significant differences in mechanical properties of old and new spruce wood. In contrary to oak wood, there were also no significant differences in fungicidal properties, considering that spruce wood has lower durability than oak wood. Same as with oak wood, G. trabeum was found to be the most aggressive fungus. Ageing of beech wood resulted in a big drop in all of the tested mechanical properties, but showed no significant differences in fungicidal properties. Here is where the low durability of beech wood really shows. The old beech wood specimens were moderately deteriorated by insects and fungi, which was the reason for loss of bending and compressive strength.