Your search resulted in 246 documents. Displaying 25 entries per page.
Surface moulds and staining fungi on acetylated wood – effect of increasing acetyl content
2013 - IRG/WP 13-10797
Wood used in outside applications is susceptible to weathering and photo degradation, which often leads to surface discoloration, loss of brightness and surface deterioration. Research has shown that acetylated wood is more resistant against brown rot, white rot and soft rot, and more dimensionally stable than untreated wood. However, acetylated wood seems still to be disfigured by surface moulds ...
L Ross Gobakken, S Bardage, C J Long II
The influence of microclimate on the moisture conditions in a Norway spruce (Picea abies (L.) Karst.) joint exposed to artificial rain
2013 - IRG/WP 13-20505
Wood structures outdoors are susceptible to decay if they are exposed to high moisture contents during long periods of time. Structures with joints that act as water traps are especially exposed since high moisture contents are reached in such positions. This paper presents a part of a laboratory study that concerns the relationship between the microclimate and the material climate, i.e. the moist...
M Fredriksson, L Wadsö, P Johansson
Characterization of test fields
2013 - IRG/WP 13-20508
Test field characteristics and impact of test fields on wood degradation is important when testing wood protection. The current EN 252 standard has no requirement for knowledge of decay hazards, but most commonly a test field is known as a “brown”,- “white”,- or “soft rot” field. To understand which decay hazard wood preservatives are tested against, each test field should be character...
U Råberg, N Terziev, G Daniel
The assessment by visual grading, change of color and ergosterol content ratings, the resistance to mould fungi of treated with wood preservative Scots pine sapwood
2013 - IRG/WP 13-20514
The filamentous (mould) fungi belonging to Ascomycetes, Deuteromycetes group are an cosmopolitan organisms which attacks wooden elements disfiguring them, dropping their value and causing environmental and health hazard. The fungi in a short time cause mainly disfigurement of wood does not effect on strength properties of wood, but with strong prolongation of duration of conditions favourable for ...
A Fojutowski, A Koziróg, A Kropacz
Extraction and analysis of DNA from green and seasoned timber as basic methods for determination of wood species and origin
2013 - IRG/WP 13-20523
Against the background of the European timber trade regulation EUTR, commenced to law by March 2013, the determination of wood species and tracing of its origin is getting a great importance. A promising approach for establishing fast and reliable tracking systems for wood products is DNA analysis. A critical point is the extraction of analysable DNA from the wood and its lignified cell walls. Thu...
K Jacobs, H Mende, W Scheiding
Moisture distribution in glulam beams with natural cracks observed with CT Scanning before and after rain
2013 - IRG/WP 13-20534
The way cracks in outdoor wooden constructions affect durability is an interesting topic, since a certain amount of cracks can always be found naturally in wood and glued laminated wood. The question in this was, can cracks lead water into the wood and thereby increase the risk for decay and reduce strength and service life. Moisture balance, i.e., water absorption and water distribution were stud...
K Sandberg
Quantification of copper and chromium in field stakes after different exposure times: Remaining metal content and distribution
2013 - IRG/WP 13-50291
In order to determine the distribution of copper and chromium as well as their remaining concentration EN 252 specimens and thicker pine sapwood stakes (non standard format) were treated with a commercial CC salt in a vacuum pressure process. The stakes were installed in the test field of the Institute of Wood Research, Hamburg, in August 2010. In all cases three stakes were removed after 4, 8, 12...
T Liese, M Bahmani, E Melcher
Molecular characterization and biodiversity of wood-decaying fungi in French Guiana
2014 - IRG/WP 14-10825
Fungi from tropical regions are currently under-represented in the classification system. Indeed, difficult access to tropical forests and irregular occurrence carpophores make it complicated to study fungus species in such environments, unlike in European zones where fungal diversity and taxonomy are better known. The purpose of this work was to enhance classification by integrating new data that...
A Zaremski, L Gastonguay, C Zaremski, J Beauchene
Microbial Community Analysis of Naturally Durable Wood in an Above Ground Field Test
2014 - IRG/WP 14-10826
This paper presents preliminary results of an above ground field test wherein eight naturally durable wood species were exposed concurrently at two sites in North America. Surface samples were taken at regular intervals from non-durable controls and compared to their more durable counterparts. Terminal Restriction Fragment Length Polymorphism was performed to characterize the microbial (bacteria, ...
G T Kirker, S V Diehl, P K Lebow
Assessment of Scots pine sapwood susceptibility to moulds by determination of fungi growth and ergosterol content in infested wood
2014 - IRG/WP 14-20540
The susceptibility of wood to filamentous fungi (mould) attack is determine mainly by laboratory methods with descriptive grading of fungal growth on the surface of the wood specimens. It is a lot of different grading scale of fungi growth, but determination of the size of fungi growth is many times not easy, not clear and often difficult. Although the filamentous fungi are not included to microor...
A Fojutowski, A Koziróg, A Kropacz
Communities of mold fungi in moisture damaged building materials
2014 - IRG/WP 14-20542
The critical conditions needed for the development of mould and decay fungi have been modelled for different building materials. However, current knowledge of indoor microbes growing on building materials relies on culture-based methods and more advanced molecular biological techniques should be employed to study the complex microbial communities in building materials. In this paper molecular biol...
E Sohlberg, H Viitanen
Modern Instrumental Methods to Investigate the Mechanism of Biological Decay in Wood Plastic Composites
2014 - IRG/WP 14-40674
Various instrumental techniques were used to study the fungal decay process in wood plastic composite (WPC) boards. Commercial boards exposed near Hilo, Hawaii (HI) for eight years in both sun and shadow locations were inspected and tested periodically. After eight years of exposure, both boards were evaluated using magnetic resonance imaging (MRI), while a selected area of the board exposed in sh...
G Sun, R Ibach, M Gnatowski, J Glaeser, M Leung, J Haight
Experiences with an industrial system for controlled thermal wood modification in pressurized unsaturated steam
2014 - IRG/WP 14-40678
Thermal wood modification in pressurized reactors has a long history, but these processes are to date industrially scarcely used, because of the relatively complicated process equipment, compared to the more common high-temperature processes in kilns at atmospheric pressure. However, based on our practical experience with the FirmoLin® process, supported by recent scientific findings, it is foun...
W Willems
Interpretation of moisture monitoring data - Relevance of moisture content thresholds for fungal decay
2015 - IRG/WP 15-10839
It is widely accepted that besides temperature wood moisture content (MC) is the key factor when it comes to durability of wooden structures exposed to weathering. Many approaches to predict the service life of wooden structures have therefore been based on using wood MC as one major input-variable to develop dose-response relationships between material climate and decay response. However, to impr...
L Meyer, C Brischke
Introduction of the COST FP 1303 Cooperative Performance Test
2015 - IRG/WP 15-20567
COST Action FP 1303 “Performance of bio-based building materials” successfully started in October 2013 and an ambitious program was set up for the four year programme. COST Actions provide an excellent opportunity for collaborative research, e.g. in the frame of Round Robin tests. The idea of this respective test was to distribute a fairly simple test set up to as many places in Europe as poss...
M Humar, C Brischke, L Meyer, B Lesar, N Thaler, D Jones, S Bardage, C Belloncle, J Van den Bulcke, J M Abascal, G Alfredsen, D Baisch, B Brunnhuber, G Cofta, E Grodås, E Frühwald Hansson, M Irle, H Kallakas, J Kers, M Klamer, P Larsson Brelid, A B Maider, K C Mahnert, E Melcher, R Möller, M Noël, L Nunes, G A Ormondroyd, S Palanti, N Pfabigan, A Pilgård, A O Rapp, P Schumacher, E Suttie, T Teppand, M Touza, J Van Acker
Mould growth on spruce claddings and the effect of selected influencing factors after 4 years of outdoor testing
2015 - IRG/WP 15-30671
Norway spruce (Picea abies) is the most frequently chosen wood species as claddings in façades in Norway, and is used both coated and uncoated. The visual changes that occur during weathering can be colour changes, abrasion or wear, blistering, flaking, and even cracks in the wood or coating, but more often growth of mould and blue stain fungi is the main challenge. A field test with synchronous monitoring of relative humidity, air temperature, material temperature and wood moisture content in Norway spruce claddings has been performed in southern Norway as part of the ClimateLife project. Visual evaluation of blue stain and mould growth according to EN 927-3 was performed, and evaluation data after 46 months exposure is presented. The objectives were to study the effect of 1) environment, 2) cardinal direction and 3) colour of the coated surface on growth of blue stain and mould fungi and to study the variation in relative humidity, air temperature, wood moisture content and material temperature. After 46 months exposure, the red coating system had generally the lowest mould ratings and the uncoated claddings had the highest. Of the white coloured claddings the ones facing south had lower mould ratings than those facing north, but the opposite were found for red coloured claddings. The relative humidity was higher in front of claddings exposed northwards and in a shaded environment compared to an open environment against south. In an open environment red coloured claddings had the lowest wood moisture content and highest material temperature, and red coloured claddings against south had the highest maximum material temperature.
L Ross Gobakken, G I Vestøl
Fungal decay of archaeological waterlogged oak timber: role of the mineral content
2016 - IRG/WP 16-10873
In service, wood foundation poles are subjected to water level fluctuation in soil. While wood is saturated by water only bacterial decay occurs. When oxygen content increases and moisture content decreases, severe fungal attack may occur. To evaluate the long term fungal durability of wood foundation pole in the context of service, 300 years waterlogged archaeological wood poles were used. The oa...
A Besserer, M Letellier, E Fredon, Q Kleindienst, M-L Antoine, C Perrin, J Lallemand, C Rose, M-C Trouy
Variation in moisture content in field trials according to use class 3.2 conditions
2016 - IRG/WP 16-20580
Different test methods to determine the durability of wood in use class 3 (EN 335:2013) are available. Fungal degradation of wood requires liquid water. Different Standards (EN 335-1:2006; DIN 68 800:2011) specify the risk for decay with moisture content (mc) of above 20%. EN 335 (2013) does not specify moisture content but rather defined limited wetting conditions (use class 3.1) or prolonged wet...
S Bollmus, A Gellerich, H Militz
Superhydrophobic treatment of Norway spruce wood for improvement of its resistance against brown rot and moulds
2016 - IRG/WP 16-40734
Water repellence of wood can be increased and its some other properties influenced by introduction of hydrophobic chemicals into and on cell walls without affecting the wood’s bulk density due to lumen filling. Herein, a simple dipping method to insert octadecyltrichlorosilane (OTS) into cell walls and to deposit the self-assembled hydrophobic monolayers (SAMs) of OTS is reported. It was found o...
A Kumar, P Ryparová, P Hajek, B Kričej, M Pavlič, A S Škapin, M Šernek, J Tywoniak, J Žigon, M Petrič
Role of cell wall specific moisture content on the brown-rot fungal attack on wood
2016 - IRG/WP 16-40736
Wood is a hydroscopic resource because the cell wall polymers contain hydroxyl and other oxygen-containing groups that attract moisture through hydrogen bonding. Moisture content varies with changing moisture content in its environment. The moisture content in wood is responsible for many of the performance properties we observe. The strength properties of wood are dependent on the moisture con...
R M Rowell
Estimation of wood degradation determined by visual inspection, mechanical testing and DNA characterisation – report after 3 years of exposure
2016 - IRG/WP 16-30700
The influence of two separate treatments, thermal modification and alkaline copper quaternary (ACQ, Silvanolin©) treatment, on fungal decay, visual disfigurement, deterioration in mechanical properties and fungal community structure was assessed on Norway spruce (Picea abies) and compared with the performance of two naturally more resistant tree species native to North America: Douglas fir (Pseud...
N Thaler, T Martinović, M Bajc, D Finžgar, H Kraigher, A Sinha, J J Morrell, M Humar
Genetic characterisation of the deathwatch beetle – Call for support
2017 - IRG/WP 17-10890
The deathwatch beetle (Xestobium rufovillosum) is one of the most important pests of historical wood constructions. Further analysis of the exact nature of the feeding habits regarding diet and wood characteristics might deliver answers for controlling this pest. Also there is little known about genetic variability and population structure within the species. For analysis of infested wood and also...
M Höpken, E Melcher, J Trautner
Case study: “Riesenbühlturm”
2017 - IRG/WP 17-20599
In this case study four 7 m long Douglas fir crossbeams were investigated regarding the remaining metal and moisture content. The crossbeams were replaced from a timber tower after 10 years of service in the Black Forest region (South Germany) due to fungal decay. From each of the crossbeams five stem discs were taken and relevant parameters (density, moisture and remaining metal content) were de...
E Melcher, J Müller
The sorption behaviour of wood
2017 - IRG/WP 17-20605
The use of dynamic vapour sorption to determine the sorption properties of wood has become an increasingly popular technique. The method has many advantages when compared with many other gravimetric methods. However, it is necessary to set an equilibrium condition in order to obtain data for an isotherm in a reasonable amount of time. An important recent finding has been that multiple sorption cyc...
C Hill
Modelling of moisture content in timber bridge details
2017 - IRG/WP 17-20613
The design of details is an important aspect in durability design of timber bridges. Details are often considered the weakest points in bridges due to their tendency to trap and accumulate moisture and thus facilitate decay. When designing maintenance plans and inspection intervals, it is important to know how design choices will come to influence the service life. Moreover, service life and wood ...
J Niklewski, C Brischke, E Frühwald Hansson, L Meyer-Veltrup