Your search resulted in 191 documents. Displaying 25 entries per page.
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
The copper-transporting ATPase pump and its potential role in copper-tolerance
2016 - IRG/WP 16-10859
Copper-tolerant brown-rot decay fungi exploit intricate mechanisms to neutralize the efficacy of copper-containing preservative formulations. The production and accumulation of oxalate is the most widely recognized theory regarding the mechanism of copper-tolerance in these fungi. The role of oxalate, however, may be only one part of a series of necessary components required for this complex mecha...
K M Ohno, C A Clausen, F Green III, G Stanosz
Susceptibility of wood substrates to Aurebasidium pullulans at different temperatures
2016 - IRG/WP 16-10863
There is an increasing awareness of how the aesthetical performance of wood exposed outdoors changes over time and especially in the first few years after installation. Mould and blue stain fungi are biological agents that contribute to the weather grey colour on a wooden façade, and the blue stain fungi Aureobasidium pullulans is commonly identified as colonizer on coated and uncoated wood expos...
L Ross Gobakken, G Alfredsen
Fabrication and characterization of MicroPCMs filled wood-plastic composites: Effects of polyethylene glycol on melamine–formaldehyde shell material
2016 - IRG/WP 16-40728
Microencapsulated phase change materials (MicroPCMs) containing dodecanol were fabricated using melamine-formaldehyde (MF) or polyethylene glycol 200 modified melamine-formaldehyde (PMF) resin as the shell materials by in situ polymerization. Wood flour/high-density polyethylene (WF/HDPE) composites with MF shell MicroPCMs (MF-MicroPCMs) or PMF shell MicroPCMs (PMF-MicroPCMs) were prepared, respec...
Xi Guo, Jinzhen Cao
The influence of log soaking temperature and thermal modification on the properties of birch veneers
2016 - IRG/WP 16-40749
In veneer manufacture the logs are routinely soaked in heated water baths in order to soften the wood prior to peeling. The temperature of the water may vary greatly between batches; however, the influence of log soaking temperature on veneer properties has had little research attention. Uncontrolled moisture is known to cause problems in wood-based materials, while thermal modification offers a m...
S Källbom, K Laine, M S Moghaddam, A Rohumaa, K Segerholm, M Wålinder
Effects of climatic factors and material properties on mould growth on untreated wooden claddings
2017 - IRG/WP 17-10884
Mould growth is an important contributor to colour change of untreated wood exposed outdoors. Predicting the development of mould growth is therefore important to ensure successful use of untreated wood as a façade material. More knowledge about the factors affecting mould growth on outdoor exposed wood is required to give better predictions. In this study, climatic factors and material propertie...
S Karlsen Lie, G I Vestøl, O Høibø, L Ross Gobakken
Untreated and copper-treated wood soaked in sodium oxalate: Effects of decay by copper-tolerant and copper-sensitive fungi
2017 - IRG/WP 17-10888
Copper is widely used as the primary component in wood protectants because it demonstrates a broad range of biocidal properties. However, a key concern with using copper in wood preservative formulations is the possibility for brown-rot basidiomycetes to resist the toxic effect. Many brown-rot basidiomycetes have evolved mechanisms, like the production and accumulation of oxalate, which helps thes...
K M Ohno, G T Kirker, A B Bishell, C A Clausen
Activity of Two Strobilurin Fungicides Against Three Species of Decay Fungi in Agar Plate Tests
2017 - IRG/WP 17-30704
The objective of this study was to examine the toxicity of strobilurin fungicides against wood decay fungi in order to assess their potential to act as a co-biocide for copper-based wood protection. Two strobilurin fungicides, Heritage (50% azoxystrobin active ingredient) and Insignia (20% pyraclostrobin active ingredients), and copper sulfate pentahydrate were tested against one white rot fungus...
J D Tang, T Ciaramitaro, M Tomaso-Peterson, S V Diehl
Influence of hygro-thermal treatment temperature and duration on dimensional stabilisation of wood modified with poly(butylene succinate)
2017 - IRG/WP 17-40813
To improve wood properties, especially dimensional stability, a treatment based on poly(butylene succinate) oligomers (OBS) was experimented. After impregnation in wood, a further hygro-thermal treatment (HTT) was carried out in a pressurized reactor at 100% relative humidity (RH) at differing temperatures for differing durations. The aim of HTT is to induce partial swelling of wood cell walls so ...
C Grosse, M Noël, L Rautkari, P Gérardin
Impact of temperature and relative humidity on spatio-temporal fungal growth dynamics of Basidiomycetes
2018 - IRG/WP 18-10905
Basidiomycetes can cause considerable damage to wood and other bio-based building materials. Knowing at which environmental conditions these decay fungi generally thrive, and how the environmental conditions affect fungal growth characteristics, is therefore of particular interest. In this paper, we use image analysis to assess the impact of the environmental conditions on the growth dynamics of C...
L De Ligne, G Vidal-Diez de Ulzurrun, J Van den Bulcke, J M Baetens, B De Baets, J Van Acker
Monitoring of the building made of CLT in Ljubljana
2019 - IRG/WP 19-40860
Wood is one of the most important construction materials and its use in building applications has further expanded in recent decades, predominately due to development of the modern composites, like cross-laminated timber. In order to enable even more extensive and reliable use of wood in outdoor applications, factors affecting wood’s service life need to be understood. It is well known that fung...
M Humar, D Krzisnik, B Lesar, N Thaler, B Dujic
Promoting Commercially Available Epoxy Resins for Non-biocidal Wood Preservation
2019 - IRG/WP 19-40877
Commercially available epoxy and polyamine resins were evaluated with the aim of developing new non-biocidal wood preservation treatments. A simple method allowing the impregnation of wood by vacuum double impregnation followed by a curing process was developed for two reference species, beech Fagus sylvatica and Scots pine Pinus sylvestris. The tested products were evaluated for their ability to ...
P Poveda, M Mubarok, S Dumarcay, M Montibus, I Le Bayon, M Kutnik, P Gerardin, F Simon
Moisture and temperature conditions in an old, highly moisture-loaded timber building in the Røros municipality, Norway
2020 - IRG/WP 20-10966
A 150 years old log building near Røros, Norway, has been in active use as a cowshed since its erection. The animals are kept inside the cowshed all winter and this causes a situation of a high moisture load on the wooden floor, wooden walls and ceiling. Logging of temperature and humidity over one year shows that there are favourable levels of moisture in the wood and air for development of moul...
M Sand Austigard, J Mattsson
Premature adhesion failure of exterior wood coatings – The influence of substrate temperature at coating application and moisture accumulation during storage
2022 - IRG/WP 22-40937
The present study aimed at extending the knowledge about premature coating failures of industrially finished wood cladding. Two potential factors were studied: the influence of substrate temperature at coating application and moisture accumulation during storage on the adhesion of waterborne coating systems. In the first experiment, 4 batches of wood specimens were submitted to 4 different tempera...
U Hundhausen
Evaluation of the effectiveness of soaking of high-temperature plywood in low-temperature oil-based wood
2023 - IRG/WP 23-40991
We conducted a preliminary investigation to determine if soaking high-temperature plywood in a low-temperature preservative solution could achieve deeper penetration of the preservative, even in plywood made with refractory wood species such as Japanese larch. Specimens cut from commercial plywood (Japanese larch) were stored at various temperatures before being soaked in the preservative solution...
T Miyauchi, S Isaji, H Shibui, N Furuta, J Miyazaki, H Matusnaga
Modelling the service life of wood in ground contact – Verification of remotely sensed soil data from the reanalysis dataset ERA5-Land using in-situ measurements at a test site of utility poles in Eastern Norway
2024 - IRG/WP 24-41003
This study compared soil moisture and temperature estimates from the 5th European reanalysis (ERA5-Land) dataset with in-situ measurements to assess the accuracy and applicability of ERA5-Land data for modelling the service life of wood in ground contact. The ERA5-Land soil temperature estimates showed a moderate correlation with the in-situ temperature measurements (Spearman’s ρ of 0.73) and a...
U Hundhausen, P B van Niekerk, B Marais