Your search resulted in 36 documents. Displaying 25 entries per page.
Nondestructive Evaluation of Oriented Strand Board Exposed to Decay Fungi
2002 - IRG/WP 02-20243
Stress wave nondestructive evaluation (NDE) technologies are being used in our laboratory to evaluate the performance properties of engineered wood. These techniques have proven useful in the inspection of timber structures to locate internal voids and decayed or deteriorated areas in large timbers. But no information exists concerning NDE and important properties of wood composites exposed to dec...
B Illman, V W Yang, R J Ross, W J Nelson
Wood-based composites exposed to fungal degradation: Laboratory results
2001 - IRG/WP 01-40215
Oriented strandboard (OSB) and laminated veneer lumber (LVL) are widely used as residential construction materials. The durability of OSB and LVL against biological degradation has not been studied comprehensively. The objective of this research was to investigate the durability of OSB and LVL when exposed to wood decay fungi. Fourteen brown-rot and eight white-rot wood decay fungi were screened f...
V W Yang, B Illman, L A Ferge, R J Ross
Natural progression of decay in unrestrained, Southern pine sapwood exposed above ground
1995 - IRG/WP 95-20060
In this study, the natural progression of decay is being monitored in 2.4-m (8-ft) lengths of dimension lumber. The 2.4-m lengths are supported without restraint in a horizontal plane approximately 0.75 m above ground in a partially shaded field plot in southern Mississippi. The lumber is 100% sapwood. Prior to installation in the field, each piece was planed to exactly 38 by 89 mm² (1.5 by 3.5 i...
R C De Groot, R J Ross, W Nelson
Durability of surface coating systems. Mycologg - an accelerated mycological test.
2004 - IRG/WP 04-20301
Field testing and natural aging/degradation of test sample, e.g. coated wooden surfaces is a slow process. Accelerated tests focus on mechanical properties, water uptake or sometimes stain fungi.
Artificially weathered coated panels are not easily compared with naturally aged panels, and show the importance of involving the biological component among the degrading facors. It is a need for acce...
L Ross Gobakken, J Mattsson, B Jacobsen, F G Evans
Nondestructive assessment of biodegradation in southern pine sapwood exposed to attack by natural populations of decay fungi and subterranean termites
1994 - IRG/WP 94-20042
Field methods for evaluating decay resistance of experimentally treated materials lack a means for quantitative measurement of residual strength. Quantitative relationships between speed of impact-induced waves travelling parallel to the grain and residual compressive strength have been demonstrated in softwood attacked by brown rot-decay fungi, but the effects of termites have not been documented...
R C De Groot, R J Ross, W Nelson
Effects of the sulfuric acid modification of CCA treating solution
1987 - IRG/WP 3415
Sulfuric acid modification of CCA treating solution is often used to control the formation of sludges and undesirable deposits on the surface of treated wood. The consequences of sulfuric acid addition are examined in this work and negative effects are shown to far outweigh any benefits. Major risks include the loss of copper due to leaching from treated wood and the accelerated corrosion of treat...
R F Fox, H J Fry, E A Pasek, A S Ross
Growth and succession of mould on commercial paint systems in two field sites
2007 - IRG/WP 07-30421
Discolouring fungi reduce the service life of coated wooden claddings in façades and increase the total cost of ownership due to shorter maintenance intervals. It is of major importance to find paint systems for wood which are durable and have a high resistance to mould growth. A total of 15 paint systems from 9 different manufacturers were exposed on two field sites, Sørkedalen and Birkenes, ...
L Ross Gobakken, K M Jenssen
In-service performance of wood depends upon the critical in-situ conditions. Case studies.
2008 - IRG/WP 08-20382
Wood is a unique building material, but is by nature designed to deteriorate. A detailed
understanding of the factors and interactions involved are important when working with service life prediction of wooden components in buildings. Wood may experience exponential fungal degradation caused by variation in the climatic factors within a small limited area and by minor imperfection in the wooden ...
L Ross Gobakken, J Mattsson, G Alfredsen
Assessment of mould growth on coated wood - methods and application
2009 - IRG/WP 09-20423
Discolouring fungi reduce the service life of coated wooden claddings in façades and increase the total cost of ownership due to shorter maintenance intervals. The project “Enhanced service life on coated wooden facades” has as its main objective to develop new methods for early prediction of durability and longer aesthetic service life of coated wooden cladding related to consumer needs and ...
L Ross Gobakken, C M Whist, O Høibø, P J Hovde, E Larnøy
Effects of global climate change on mould growth - Interactions of concern
2010 - IRG/WP 10-50270
An evident change in climate the last decades has been recorded, and combined effects of increased CO2, elevated temperature and altered precipitation regimes have been observed to represent a change to the fundamental drivers within ecosystems. Growth of moulds, both in nature and on man-made constructions and objects, will most likely increase due to changes in the climate. The survival, the rep...
L Ross Gobakken
Quantification of four dark colored mould fungi by real time PCR
2011 - IRG/WP 11-10754
Coated wooden claddings in building facades are widely used in the Scandinavian countries, and are often preferred to other materials. Wood is facing increasing competition from other materials that are less labor intensive at the construction site and materials with less demand for maintenance thru service life, and makes further development of wooden claddings essential. Growth of discoloring mo...
E Larnøy, L Ross Gobakken, A M Hietala
Aesthetic service life of coated and uncoated wooden cladding - influencing factors and modelling
2011 - IRG/WP 11-20470
Mould growth on exterior coated cladding façades is an undesirable element and will often shorten the aesthetical service life. Mould growth on painted surfaces is influenced by type and concentration of film fungicides, the paint formulation and the wood substrate itself, and wooden cladding may experience exponential fungal deterioration caused by variation in the climatic factors, often within...
L Ross Gobakken, O A Høibø
TRU-CORE Process for Treatment of Refractory Species and Engineered Wood Products
2011 - IRG/WP 11-40573
The TRU-CORE Process is a novel, chemically-based technology for rapidly delivering globally accepted wood preservatives and insecticides deep into the core of wood and wood-based composites in a waterborne carrier. Protectant materials which can be utilized with the TRU-CORE Process include a variety of carbon-based fungicides and insecticides. An important feature of the TRU-CORE Process is it...
A S Ross
Effects of microclimate, wood temperature and surface colour on fungal disfigurement on wooden claddings
2012 - IRG/WP 12-20490
Wooden claddings are common in façades in Norway, and Norway spruce (Picea abies) is the most frequently used species. The cladding is a major part of the facade, and it has visual requirements that may define the aesthetic service life. 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 of...
L Ross Gobakken, G I Vestøl
Post-Manufacture Biocide Treatment of Engineered Wood I-Joists
2012 - IRG/WP 12-40596
Engineered wood I-joists, fabricated from laminated veneer lumber (LVL) flanges and oriented strand board (OSB) webs, offer many advantages over solid sawn lumber joists in residential and light commercial construction. With the expanded use of these products has come an increasing need to be able to treat them with biocides to prevent attack from decay fungi and termites during service. Historic...
A S Ross, R W Clawson
Field-testing of Norway Spruce Claddings with Monitoring of Moisture Content, Material Temperature and Microclimate
2012 - IRG/WP 12-20502
The physical function of a cladding is to protect the interior construction. Under normal circumstances the performance requirements can be met for a very long time, meaning that the technical service life of a wooden cladding can be very long. Since the cladding is a major part of the facade, it also has visual requirements that may define the aesthetic service life, and often it is much shorter ...
G I Vestøl, L Ross Gobakken
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
System treatments of Pinus sylvestris - influence on moisture, decay and discoloration
2013 - IRG/WP 13-30612
Biological activity can cause challenges for the use of wood in outdoor exposure. Decay and discolouring fungi influence the service life of wooden constructions, and the moisture content of the wood is often an important factor. The aim of this study was to evaluate the performance of different combinations of preservative/modified wood protection treatments and surface treatments for wooden deck...
A Schabacker, G Alfredsen, L Ross Gobakken, H Militz, P O Flæte
Using hyperspectral imaging to detect and quantify mould and blue stain on coated and uncoated wood
2014 - IRG/WP 14-10822
Hyperspectral imaging has been applied on the surface of samples of coated and uncoated Norway spruce (Picea abies) as a new technique to detect and quantify growth of mould and blue stain fungi. Principal Component Analysis of the hyperspectral images resulted in a clear visualization of the fungi and the amount of mould coverage could be estimated. This indicates that NIR hyperspectral imaging c...
L Ross Gobakken, I Burud, A Flø, K Kvaal, T K Thiis
New Method for Pretreatment of Railroad Crossties
2014 - IRG/WP 14-40675
Creosote has been successfully utilized for nearly 150 years for the protection of railroad crossties (sleepers) in the USA and remains today as the most widely used wood preservative for this application. One of the few shortcomings of creosote as a preservative is its inability to penetrate many of the refractory hardwood species which make up the majority of crossties in the USA. Lack of full...
A S Ross, R W Clawson Jr
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
Bio-friendly preservative systems for enhanced wood durability - the first periodic report on DURAWOOD
2015 - IRG/WP 15-30677
The objective of the paper is the DURAWOOD scientific project carried out within Polish-Norwegian Research Programme, which lasts from September 2013 till August 2016. The aim of the project concentrates on the developing of a new, eco-friendly and biocide-free wood protective systems as an alternative to traditional, commonly used preservatives or coatings, containing biocides. Several wood prese...
B Mazela, M Broda, W Perdoch, L Ross Gobakken, I Ratajczak, G Cofta, W Grześkowiak, A Komasa, A Przybył
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
Formation of biofinishes on outdoor exposed wood; the impact of wood-oil combination and geographical location
2016 - IRG/WP 16-10864
Growth of dark moulds enables the use of a decorative and protective biofinish for wood, showing advantages compared to traditional wood-coatings in terms of sustainability and self-repair. Based on the formation of a uniform mould covering on oil treated wood during outdoor exposure, the utilisation of a biofinish is in development. Basic information is lacking on the correlation between exposure...
E J van Nieuwenhuijzen, L Ross Gobakken, M F Sailer, R A Samson, O C G Adan
Weather degradation of thin wood samples
2016 - IRG/WP 16-20578
Untreated wooden surfaces degrade when exposed to varying doses of natural weathering. In this study, thin wood samples were studied for weathering effects with the aim of modeling the degradation utilizing Near-infrared hyperspectral imaging. Several sets of samples were exposed outdoors for time intervals from 0 to 21 days, and one set of samples was exposed to UV-radiation in a laboratory chamb...
I Burud, K A Smeland, K Hovde Liland, T K Thiis, J Sandak, A Sandak, L Ross Gobakken