Your search resulted in 175 documents. Displaying 25 entries per page.
A case study on quality control on telephone poles as a cost saving tool in Tanzania
1987 - IRG/WP 3418
A sample of 28 CCA treated Eucalyptus poles from a lot of 2,000 poles awaiting delivery to the field, was studied to reveal the quality of treatment. Results showed a product of very poor quality. Average figures for penetration and retention were 8.4 mm and 2.2 kg/m³; these results are 66% and 91% below the required standards, respectively. Consequences of such results are estimated to amount to losses of billion of shillings.
K K Murira
The long-term performance of boron treated joinery in service - A case study
2000 - IRG/WP 00-20208
Joinery treated with borates 23 years ago and in service in residential flats was surveyed and analysed for boron content. The levels of boron still present were sufficient to prevent decay. None of the windows surveyed showed any decay despite the fact that moisture and sapwood contents were conducive to decay.
D J Dickinson, R J Murphy
The role of communication in the field of environment protection: A case study "Wood Protection"
1990 - IRG/WP 3574
Biocides - Efficacy assessment and doses for wood preservatives (product type 8). Local/geographical aspects. Termite control as case study
1999 - IRG/WP 99-20181
Currently, the efficacy of a wood preservative, as biocidal product type 8, is assessed as a ‚critical value' (CV), an efficient dose (retention in wood at a given depth of penetration). CVs are planned to be adapted for exposure to basic target organisms (5 hazard classes) and additional requirements concerning the occurrence of local target organisms in relation with climate, building design and relevant economical impact. Among them, the termite case study is illustrative. The vote of a french law, on 26 may 1999, aiming to protect consumers and to organize termite control puts termites, a "local target at the euro scale and a universal one in some euro territories", in the spotlights of actuality and helps to point out some of the remaining questions raised by the implementation of Dir 98/8 on Biocides. Based on CEN/TC/38 simulated use tests, which doses have to be used for conditions of exposure and climate, ranging from polar to tropical? Practical proposals are made to take into accound local prescription based on actual target organisms, and move on to standard biocide profiles.
Current models used by the European Health Authorities to evaluate the volatilization of active ingredients from treated wood used inside dwellings. A case study: Volatilization of azaconazole and propiconazole from treated wood
1990 - IRG/WP 3565
The use of wood preservatives inside houses may result in measurable aerial concentrations of active ingredients. These airborne contaminants may be inhaled by the inhabitants over periods lasting from a couple of days to several months. To assess the potential health hazard of preservative residues in the air, various risk-assessment models have been worked out. Three schemes, currently used by the European health authorities, are discussed in this paper. They are based on the saturated air vapour concentration, the volatilization rate measured in laboratory experiments and the aerial concentrations determined in practice. For each model various safety margins can be calculated. These are based on e.g. the subchronic inhalation toxicity, the acceptable daily intake and the acceptable aerial concentration of the insecticides and fungicides used in wood preservatives. In order to demonstrate the feasibility of these health- assessments, a case study has been carried out with the fungicides azaconazole and propiconazole, developed by Janssen Pharmaceutica - Belgium.
A R Valcke, L Van Leemput
Life cycle analysis of utility poles. A Swiss case study
1995 - IRG/WP 95-50040-05
Use of preservative-treated wood products faces increasing public and political pressure because of environmental concerns regarding the chemicals used to protect the wood. However, critics usually focus only on one single aspect of the whole life cycle of treated wood products, disregarding other environmental effects of timber utilization. To evaluate the ecological consequences of wooden utility poles (CCF/CCB impregnated roundwood and glulams) and their alternatives of reinforced concrete and steel, a life cycle assessment was conducted. Based on data from existing Swiss electricity transmission lines, a comprehensive inventory was established of all extractions from, and emissions to the environment caused by each process step. This inventory data was linked to possible environmental impacts using various aggregation methods. An evaluation was made for single poles as well as for whole transmission lines. The results show that impregnated roundwood utility poles in fact have certain environmental benefits when considered over their whole life cycle.
T Künniger, K Richter
Structural defects in CCA treated timber fence posts: A case study.
1997 - IRG/WP 97-40084
Since 1983 an environmental improvement programme has been in progress in the city of Dundee. This programme included the erection of rail and pale timber fencing throughout the city. The timbers had been pressure treated with CCA prior to painting with 2 coats of an exterior wood stain finish. However, the larger dimension timber fence posts (100 x 125 x 1500 mm3) regularly developed severe checks/shakes in service. These defects raised questions regarding the continued use of timber as a fencing material by the municipal authoritiy due to concerns relating to the long term efficacy of preservative treatment and timber durability. Statistical models generated from visual and physical measurements of aged post timbers recovered from field sites in the city indicated that a reduction in the development of structural defects was associated with lower heartwood:sapwood ratios. The sites from which posts were recovered also influenced defect development indicating inconsistent timber quality specifications and/or pronounced variation in environmental conditions at each site. This paper highlights the problem of many municipal authorities who, through lack of available information, fail to implement specifications for treated timber components tailored to their specific requirements.
S Muhsin, D C R Sinclair, A Bruce, H J Staines
Control of termite attack using a trapping method and acoustic emission (AE) monitoring a case study at an electric power plant
1997 - IRG/WP 97-10224
To prevent subterranean termites (Coptotermes formosanus Shiraki and Reticulitermes speratus Kolbe) from invading the buildings of an electric power plant and to control their attack, artificial traps were buried around the buildings. The attack of the termites in and around the traps was monitored by detecting acoustic emissions (AE) generated by the feeding behavior of the workers. The cylindrical artificial traps were 600 mm long and 300 mm in diameter, and consisted of pieces of Japanese red pine surrounded by slender polystyrene foam sticks. Termite inhabitation was observed in eight of the ten traps set, and particularly high levels were found in three traps. The traps were renewed every one or two months. The amount of termites inhabiting the traps decreased drastically after the first renewal, but varied only slightly over the following two and a half years. The amount of termites in the traps increased when the traps were not renewed. Termite activity was significantly restricted by installing artificial traps and no additional serious attacks were found in or around the buildings during the study period. AEs generated by feeding activities were monitored by piezoelectric AE sensors attached to the wooden sticks in the traps or to wooden bait stakes near the trap. The rate of AE events varied according to feeding activity which was associated with the number of termites in the trap and the temperature.
Y Fujii, Y Imamura, E Iwatsubo, S Yamamoto
Remediation of a site contaminated with creosote and CCA - a case study
1998 - IRG/WP 98-50101-12
Over sixty years of wood preservation activity conducted by ImpregNor at Ilseng, Norway, has caused serious contamination of the soil. High concentrations of creosote have been found at two separate sites, one in connection to the creosote wood preservation plant, and one further downstream were residues from the creosote preservation have been deposited. High levels of chromium, copper and arsenic (CCA) are found in a third area around the CCA wood preservation plant and the related dripping/fixation area. A site investigation of the contamination situation revealed that both creosote and CCA were spreading out of the wood preservation plant area directly through the sewer and drainage systems and with the ground water. There was no acute danger for exposure to humans, but further spreading would increase the exposure risk. A remedial actions plan to prevent further spreading of contaminants was requested by the Norwegian Pollution Control Authorities in July 97. Three drainage trenches for the collection of groundwater have been constructed downstream from the contaminated areas. The trenches were excavated down to a confining low permeable clayey silt layer. HDPE membranes on the downstream wall of the trenches prevent contaminated water from migrating across the trenches. Free phase creosote and creosote contaminated water from the trenches are pumped through an oil separator constructed to remove creosote oil. The groundwater from the CCA contaminated area is collected and pumped through a sedimentation basin and reused in the preservation plant. Control of the effluent during the first six months will show if further water treatment is required. The use of in situ bioremediation to increase the remediation rate of the creosote contaminated areas will be further investigated to limit the duration of the "pump and treat" operation.
T Rødsand, K Hellum, H Lillemaehlum
Possible durability transfer from durable to non durable wood species. The study case of teak wood
2001 - IRG/WP 01-10392
Teakwood is well known for its excellent natural durability, mostly due to its high proportion of extracts. Amongst these extracts, quinones, and more precisely some naphtoquinones (such as lapachol) and anthraquinones (such as tectoquinone) appear to play a crucial role in the resistance to wood decay organisms. At a laboratory scale, sawdust from malaysian teak heartwood has been extracted under different temperatures. These extracts, as well as solutions of commercialised lapachol and tectoquinone were used to treat pine sapwood mini blocks. Such treated and leached samples were used for accelerated fungal tests using basidiomycetes. The results have shown that protection against fungi was achieved through these treatments. Nevertheless, laboratory extracts from teakwood and commercial quinones performed differently, arousing then questions on this way of preserving non durable wood species.
M-F Thévenon, C Roussel, J-P Haluk
International standardisation: a hypothetical case study with stand-alone borate wood preservatives
1998 - IRG/WP 98-20147
The possibility of developing wood preservation standards with a global remit has a number of obvious advantages as well as far reaching ramifications, many of which are undefined as yet. The commercial implications of adopting international standards are clearly considerable, but equally, such a development is likely to focus attention on the conceptual differences in the way that different regions view standards, especially with regard to test methodology and assessment. Boron-based wood preservatives have been used world-wide for a number of decades. Coupled with the fact that they have been used in a wide range of environments, this track record makes borates an excellent vehicle for exploring how international standardisation might proceed. Particular attention is paid to the protected, above ground situation and the challenge posed by potentially inappropriate test criteria, conflicting results obtained with different tests and timber variability. The underlying reasons for countries stipulating different retentions for essentially the same level of biological hazard are considered, following review of actual toxic values obtained using a variety of standard tests. Following discussion, a proposed international requirement for borate wood preservatives is given. This 'case study' concludes that there are good reasons to be optimistic about deriving working standards for wood preservatives which can usefully be adopted on an international basis. However, it has also been recognised that the task is easier in this particular case than for other preservative systems and this is discussed.
M W Schoeman, J D Lloyd
Treatment of Green Logs infested by Exotic Pest: Case Study of the Emerald Ash Borer: Agrilus planipennis Fairmaire
2007 - IRG/WP 07-10628
Invasive alien insect species periodically infest forests in the United States causing the destruction of plant species and decimating populations, resulting in significant economic and ecological losses for areas involved. The Emerald Ash Borer (EAB) was first discovered on North American soil in the summer of 2002 near Detroit, Michigan and has since spread to several other Midwestern states and Ontario, Canada, causing the destruction of ash populations. Limitations posed on the circulation of green ash logs and lumber has seriously affected the economic value of ash logs and lumber in affected regions. This study investigated over bark chemicals and non-chemical treatments for sanitization of infested logs to allow free circulation and trade for value added products. Chemical treatments included borate with concentrations ranging from 5% to 16.5% (Boric Acid Equivalent) and Imidacloprid with concentration ranging from 0.005 to 0.02% applied as spray. Non chemical methods included treatments in conventional kiln and microwave at 50°C, 55°C, 60°C and 65°C. Results obtained showed that Imidacloprid treatments concentrations of 0.01% and above were effective at sanitizing infested logs. Borate treatments resulted in significant reduction in insect emergence in indoors rearing conditions but did not achieve full control of the insect infestation. For non-chemical treatments, kiln temperatures of 65ºC were successful for sanitization of infested logs. Microwave treatments were not as effective as conventional heat for controlling insect emergence, and we hypothesized that this was due to the uneven distribution of the heat inside the microwave used in the study. Approaches to improve the microwave treatment are proposed.
P Nzokou, S Tourtellot, D P Kamdem
Wood boring species present in the Tagus Estuary and the severity of their attack on wooden piles exposed in the area: a case study
2008 - IRG/WP 08-10664
Wood exposed in the marine environment is subject to degradation by wood boring organisms. This is probably one of the reasons why wood has been substituted by concrete and steel in maritime structures in many European coastal areas. Wooden piles obtained from a wharf exposed in the Tagus Estuary, Porto Brandão (Almada, Portugal) provided an opportunity to understand the main agents of biodeterioration of wood, as wooden structures in the area are rare. The examination of the piles revealed severe deterioration by wood boring organisms. Major destruction caused by limnoriids was observed in the outer layers of the piles. The species was identified as Limnoria quadripunctata but a field survey in wooden structures nearby the area where the piles were obtained, revealed also the presence of Limnoria tripunctata. Thus, it is possible that this last species was also responsible for the degradation observed. The piles were also attacked by teredinids but the severity of their attack was less extensive than that by limnoriids. Two terenid species were identified, Lyrodus pedicellatus and Nototeredo norvagica. N. norvagica was previously reported from test panels exposed in the Tagus in the 1980’s. However, this was the first time L. pedicellatus was reported in this area. The increase in water temperature surface due to global warming might be responsible for the increased activity in southern European waters of L. pedicellatus, a warm water species. The higher activity of limnoriids in the Tagus Estuary in later years might be related not only with warmer water temperatures but also with an increase in salinity in the area, as limnoriids appear to be restricted to waters with salinities close to that of seawater. The development of adequate methods of wood protection requires accurate identification to define the borer hazard at various sites. In this study the Tagus Estuary is used as a case study. Species identification also assisted in the documentation of the activity of particularly damagin species, which enabled biodeterioration to be related with defined organisms.
L M S Borges, L Nunes, A A Valente, P Palma
Antinomic natural self-protection mechanism in long-lasting woods: a case study with three tropical species from French Guiana
2009 - IRG/WP 09-10696
We demonstrate in this work through 3 examples that Amazonian trees may specialize long-lasting woods by means of at least to different approaches. Wallaba impregnates its wood with large amounts of weakly antifungal compounds acting in synergy, while tatajuba and louro vermelho woods are naturally impregnated with antifungal agents. Comparison of biological activities in vitro and concentrations in the woods indicate that these compounds alone may account for the natural durability of the two woods.
A Rodrigues, M Royer, N Amusant, J Beauchêne, G Herbette, V Eparvier, A Thibaut, L Salmen Espíndola, B Thibaut, D Stien
Service life prediction of wooden components - Part 3: Approaching a comprehensive test methodology
2011 - IRG/WP 11-20464
This paper is the third in a series on 'service life prediction' of wooden components and should be considered as a discussion paper. The authors tried to analyze the topic with a look from a distance and comment sometimes with a smile on the current controversial discussion about SLP issues. Nevertheless, the viewpoints of different groups, such as natural scientists, engineers, approval board members, consumers, and finally wood product manufacturers, have been described and resulting conflict points have been pointed out. Conceptual differences in modelling the performance of wooden components have been studied and related problems have been highlighted exemplarily on the base of 'hard' field test data. Problems related to the classification of wood durability are addressed as well as test methodological aspects. Finally a series of promising test methods and assessment procedures is presented. Moisture recordings in combination with subsequent dose assessments, comparative analyses of lab and field trials, and further new field test methods proved to have the potential to contribute to a comprehensive test methodology for wood based products. This is demonstrated based on preliminary results and summarized in a proposal for future test design requirements.
C Brischke, C R Welzbacher, L Meyer, T Bornemann, P Larsson Brelid, A Pilgård, E Frühwald-Hansson, M Westin, A O Rapp, S Thelandersson, J Jermer
The importance of proper taxonomic identification, a case study with Reticulitermes spp. from USA
2012 - IRG/WP 12-10774
Taxonomy has been evolving with recent advancement in molecular and internet technologies. The importance of a stable taxonomic foundation is unquestionable as this science provides crucial information about evolutionary relationships and allows questions about the life history and ecology of organisms to be asked. We hope to highlight the issues and lessons we have learned from revising the taxonomy of the native subterranean termite from the southeastern region of the United States in this paper.
Su Yee Lim, B T Forschler
A case study of investigating fungi that affect traditional Japanese shake roof with/without copper plates
2013 - IRG/WP 13-10810
A Japanese traditional shake roof is made from split logs. To keep the roof long, copper (Cu) plates are often inserted between the shakes. It has been thought that Cu elements from copper plates would flow out when a shake roof is exposed to rain and inhibit growth of wood rotting fungi. Actually there are some examples where the Cu plates seem to be effective in preventing fungal damage, but on the other hands, there are also cases that significant rot is observed even with insertion of Cu plates. It is important to look at what is going on in such wooden roofs, by describing levels of damage of rot and investigating fungal species, which are involved in the damage. In this study, we investigated a case of shake roof where Cu plate usage seemed to have inhibited wood rot. Wooden parts away from copper plates were decayed with deep cracks, and wooden parts under a copper plate have been preserved well and maintained its original form. Wooden samples, which did not have significant decay visually, were taken from the areas just under copper plates. Also wooden samples, which had severe decay, were taken from areas without copper plates. Filamentous fungi in both types of samples were identified using a cultivation method on malt extract agar (MA) medium and a non-cultural method, the next generation sequencing method. Fungal strains were isolated on MA plates from ethanol-sterilized wooden pieces and non-sterilized pieces respectively, to see fungal species rich on the surface and inside the wooden pieces. Surface sterilization resulted in a big difference from the results obtained with non-sterilized samples. But for now it is unclear whether there are difference in fungal species between the samples taken from the areas adjacent to Cu plates and samples taken from the areas without Cu plates. By using next generation sequencing technology, 12826 (Sample 1, away from copper plates) and 7086 sequences (Sample 2, just under a copper plate) were yielded. ITS DNA sequences from Sample 1 (samples taken from areas without Cu plates) were divided into 3 groups. The main group (11619 sequences) was highly-homologous to species classified as wood rot fungi. The other groups were classified as ascomycetes. On the other hand, ITS DNA sequences from Sample 2 (samples taken from the areas adjacent to Cu plates) were divided into many groups but all the sequences were classified as ascomycetes. Such difference may reflect the states of wood rot, between the Cu plus and Cu minus samples examined in this study.
T Wada, Y Fujiwara, Y Fujii, R Kigawa
Wood Natural durability study source of biomolecules: case of Dicorynia guianensis Amsh. heartwood
2016 - IRG/WP 16-10871
The chemical investigations of Dicorynia Guianensis heartwood led to the isolation of four new indole alkaloids for the first time in this plant Compound (1) identified as spiroindolone 2’,3’,4’,9’ -tetrahydrospiro [indoline-3,1’pyrido[ 3,4-b]-indol ]- 2- one, and compound (3) described as nitrone 1-methyl-4,9 -dihydro-3H-pyrido [3, 4-b] indole 2 – oxide and were isolated for the first time as natural products ABTS antioxydant activity guided their isolation and showed the potential of these compounds in industrial sectors
J-B Say Anouhe, A A Adima, F B Niamké, D Stien, B Kassi Amian, D Virieux, J-L Pirate,S Kati-Coulibaly, N Amusant
Environmentally Sustainable Method of Termite Management using a baiting system: A case study in the Philippines
2016 - IRG/WP 16-50317
Environment and sustainability are key words for achieving product and business success. Use of chemicals in human vicinity such as homes and buildings are on the increase, thanks to a growing consciousness on pests. Using chemical insecticide is the main stay to counter these pests, but its role in environment is being scrutinized.Insect baiting technology has proven its success around the world and is most considerate when environment is concerned. This paper is a case study to show how an extremely small amount of active ingredient can be used to accomplishing termite elimination in place of large volume chemical application to the soil to make the work environmentally acceptable and sustainable.
A Case Study of Long-term CCA Preservative Leaching from Treated Hardwood Poles in a Humid Tropical Condition
2016 - IRG/WP 16-50324
Chromated copper arsenate (CCA)-treated Malaysian hardwoods have long been used as utility poles, posts, construction piles and motorway fencing in soil contact exposed to the threats of decay fungi and termites. Despite global concerns citing predominantly temperate conditions of long-term leaching of CCA toxic heavy metals from wood into surrounding soils and groundwater since the 1990’s, the preservative leaching severity in the tropics has been far less appreciated due to dearth of work in this area. In 2013 (after 30 years exposure), levels of total copper, chromium and arsenic within 20 treated hardwood poles of Sarawak and in soils surrounding these poles, installed in 1980 and 1981 at a plot located in Timber Research and Technical Training Centre, Kuching, Sarawak, Malaysia, were sampled. The ground is waterlogged after heavy rainfall. It is shown that there is insignificant variations of CCA salt retention in wood between 1300 cm above ground and 0-20 cm below ground (P<0.05). Nevertheless levels of these elements are significantly (P<0.05) elevated in soils surrounding, especially up to 25 mm away from, the poles than at distant sampling points (150 – 300 mm) from poles as well as at sites well away from the poles containing very low levels (<6 – 13.4 ppm) of such heavy metals. Metal levels were also highest at the soil surface directly in contact with the poles (0 – 50 mm soil depth position) and decreased with remaining 2 soil depth positions 150 – 200 mm and 300 – 350 mm. Mean extractable arsenic levels ranged from 14.5 to 100.1 ppm, chromium levels from 23.3 to 148.3 ppm and copper from 21.8 to 104.7 ppm. Results, rather than indicating relatively higher CCA leaching, concurred with that reported temperate experience and showed that soil closest to the treated poles are most contaminated, albeit slightly, after 30 years of in-ground exposure.
A H H Wong, W S M Chin
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 determined at four points (3, 6, 9, and 12 o’clock position). The results confirm the hard treatability of Douglas fir sapwood. Remaining metal content correlates with the performance of the logs, whereby following ranking was found: Eastern crossbeam > Western ≈ Southern > Northern crossbeam Beside this, the results revealed that the highest remaining metal content was determined in discs taken close to the end-grain and -in general- in lower segments (6 o’clock position) of the discs. Furthermore it was found that the applied chromium-copper-ratio can be a useful tool for the interpretation of the remaining metal content vs. metal release. The investigation of the discs enabled the conclusion that the fungal infection started in the transition zone between sap- and heartwood due to core cracks, in combination with a longer period of internal wetness. Afterwards the infection expanded predominantly in a horizontal direction. In order to avoid an early failure of the new installed crossbeams, it was suggested to protect the upper side of the logs by means of stainless steel u-profiles against weathering. A first visual inspection of the covered beams did not show any signs of damages after three years.
E Melcher, J Müller
Durability by design – a case study of the performance of wooden decks after 9.5 years of natural weathering
2019 - IRG/WP 19-20648
The service life expected for wood decking manufactured with poorly durable wood species, left untreated and exposed to severe environmental conditions such as high humidity and active biological agents, is usually assumed to be short (less than 10 years). The current classification of wood’s natural durability is based on EN standardised tests which do not fully reflect the real end-use conditions (such as outdoor decking or cladding), that might lead to underestimate the expected performance and service life of certain wooden commodities. In addition, design is known to play an important role in the performance of wooden elements over time, especially in the case of outdoor applications. With the aim of evaluating the positive impact of water-draining designs on wood’s service life, decks were manufactured using six wood species and up to six different designs, selected for their ability to generate or to avoid water traps through different design details. The decks were rated for fungal decay after 9.5 years of natural weathering in the city of Bordeaux, France. The results of the evaluation demonstrated that (1) significant difference in the ability of the decks to withstand decay over time exists depending on the design details used, the water-draining designs performing better than most of the water-trapping ones in the case of the non-durable spruce and poplar; (2) high variability in the resistance of the spruce and poplar deck boards against fungal decay was noticed for each tested design, but unexpectedly with a quite high percentage of boards of each type performing very well after such a long exposure to weathering; (3) the heartwood of larch, maritime pine and Douglas fir was found to perform very well after 9.5 years of weathering in decking application, with only slight differences observed between the selected designs, demonstrating that these species could be valued for decking applications despite their moderate natural durability.
M Kutnik, M Montibus
Towards better integration of wood protection in the forestry wood industry chain - a case study on hybrid poplar
2019 - IRG/WP 19-50359
Wood and wood products are limited in service life as in the forest ecosystem trees at end of their life are degraded to re-enter the bio-geochemical cycle. Humans can select wood species with a level of natural durability fit for an envisaged end use. Mainly those applications that require a long service life under conditions that are similar to those at soil level in a forest ecosystem have been the early focus for wood preservation. Testing wood preservatives intended for enhanced performance of wood in soil or water contact was originally based primarily on performance benchmarked with wood species having higher natural durability. Over the last decades, wood protection has altered focus towards end uses out of ground contact even sometimes specifically for interior applications. Parallel to this evolution wood modification treatments were assessed also to improve general performance of wood species. Besides an increased potential for using low durability wood species, mainly dimensional stability related properties were envisaged. The forestry-wood chain has evolved in the second half of last century from mainly production based strategies to policies based on ecosystem services in a sustainability framework. Today forests are intended to provide services for the bio-economy, human health, biodiversity and climate control. An increased need for more renewable resources both for material and energy use has initiated extra focus on the potential to produce more lignocellulosic biomass, in short to increase wood production. Forest types identified as primary forest as well as (semi)-natural forests require conservation measures limiting the option to increase volume that can be harvested. One option is to provide in complementary production in planted forests. Both forestry and agriculture can take part in this. The cultivation of poplar hybrids in the temperate regions is a key option for the current and future bio-economy. These fast-growing trees are producing lightweight hardwood material with a low natural durability. All wood protection methods are of interest to be evaluated for this wood resource, making it suitable even for high quality applications. Poplar, for many reasons, has been nominated as hardwood with the best potential to perform similarly as softwoods for applications in wood construction. Benchmarking with wood species like spruce is relevant for several engineered wood products like plywood, LVL and even CLT. Wood treatments to increase durability have also evolved from traditional wood preservation towards modification techniques such as thermally modified timber depending on the performance required or fit for purpose in relation to a specific combination of use class and service life.
J Van Acker
Carbon footprint of a cross laminated timber building – Torvbraten school case study
2021 - IRG/WP 21-50366
Torvbråten school is a public school in Asker, Norway, that has reached many sustainability goals. The school was the second in Norway to have Nordic Swan Ecolabel and has a 60 % reduction in carbon footprint compared to the reference benchmark. The building is made of cross laminated timber (CLT) and extensive wood use in general. From a wood protection viewpoint, will this sustainability sustain? We take a second look at the building and assess in term of potential scenario in carbon footprint. Production of CLT is however only about 10 % of the material carbon footprint, while insulation has the largest contribution of about 35 %. Material efficiency in production and design is highly utilised through pre-manufacturing of the building, but the outdoor areas are more challenging in finding sustainable solutions. Wood has been used in many areas of the building and some places might need more protection. Also, potentials for improving the sustainability through protection are evaluated. Can reused materials be applied in similar buildings and can the materials be reused?
L G F Tellnes, J K Naess, M R Hanssen, P-O Flate
Danish wood preservatives approval system with special focus on assessment of the environmental risks associated with industrial wood preservatives
2001 - IRG/WP 01-50166-01
The following is a description of the procedure used by the Danish Environmental Protection Agency to assess the environmental risks associated with preservatives used in the pressure impregnation of wood. The risk assessment covers issues considered to be of significance for the environment and which are adequately documented so as to allow an assessment. Such issues are persistence and mobility in soils, bioaccumulation and the impact on aquatic and terrestrial organisms. Unless required in special circumstances, the assessment does not apply to birds and mammals as the normal use of preservative treated wood is not expected to involve any noteworthy exposure of these groups. Approval of wood preservatives will be based on a general assessment of the environmental risk associated with the normal use of wood treated with the preservative in a realistic worst case situation. The assessment may address other aspects such as disposal and total life cycle.