IRG Documents Database and Compendium


Search and Download IRG Documents:



Between and , sort by


Displaying your search results

Your search resulted in 297 documents. Displaying 25 entries per page.


Biological Durability of Laminated Veneer Lumber from Durable and Non-Durable Wood Species
2005 - IRG/WP 05-10567
Laminated Veneer Lumber (LVL) was laboratory manufactured using veneers from decay and non decay resistant species in order to evaluate changes in the durability as a result of the LVL manufacturing process, and to test if the mixing of decay resistant species and non decay resistant species can improve durability. Laboratory soil block test and field test were conducted. The durability of solid wood was comparable to that of LVL made using the same species. For LVL made using veneer from durable and non-durable wood species, durability was improved when two faces and one core veneers were from decay resistant species.
P Nzokou, J Zyskowski, S Boury, D P Kamdem


Estimation of service life of durable timber species by accelerated decay test and fungal cellar test
2002 - IRG/WP 02-20249
Many kinds of durable wood species for outdoor uses has been imported from all over the world to Japan. However information on the natural durability of these species is not sufficient to estimate the service life of them in the climate of Japan. Highly durable species such as Jarrh, Teak, Ipe, Ekki, Selangan batu, Red wood, Western red cedar showed no significant percent mass losses by accelerated decay test according to the JIS Z2101, but some of them are degraded during fungal cellar test for 4 years . The decay rating (0:sound to 5:totally decayed) of them after 4 years exposure was 1.0, 2.0, 0.0, 1.0, 0.0, 2.3, 5.0 respectively. This results indicated that the conventional accelerated decay test could not evaluate the natural durability of these highly durable species at all. Solid wood specimens treated with boiling water at 120? for one hour are subjected to the same JIS test, and the obtained percent mass losses of these species are 1.2, 2.9, 1.9, 3.8, 4.7, 17.5, 0.0 % by a brown rot fungus, Fomitopsis palustris, and 17.5, 14.3, 3.3, 8.2, 4.2, 0.0, 18.3 % by a white rot fungus, Trametes versicolor respectively. Pre-treatment of solid wood specimens for removal of heartwood extractives before a accelerated decay test would be an effective way to evaluate the natural durability of highly durable species in a laboratory.
K Yamamoto, I Momohara


Thermal modification of non-durable wood species 1. The PLATO technology: thermal modification of wood
1998 - IRG/WP 98-40123
The PLATO technology is an innovative upgrading technology with low environmental impact, which can be applied to fast grown and non-durable wood species. This technology is based on a thermal modification of solid wood without the addition of chemicals (e.g. preservatives), consisting of a hydrothermal treatment, followed by drying and curing. The PLATO technology results in a substantial improvement of the natural durability and dimensional stability of wood with only a slight reduction in mechanical properties. Applications of thermally modified wood will include areas where a good durability and/or dimensional stability is required, e.g. garden wood and furniture, wooden sheds, canal lining, joinery, window frames, doors, claddings. In 1998/99 the PLATO technology will be commercialised in the Netherlands. In this paper features of the PLATO technology will be discussed, including selection of wood species, the PLATO process and product development, product properties and applications.
M J Boonstra, B F Tjeerdsma, H A C Groeneveld


Severe decay damages of bridges made of ekki (Lophira alata) wood known as a durable species
2000 - IRG/WP 00-10383
Bridges made of ekki (azobe, bongossi, Lophira alata Banks et Gaertn.) timbers were severely decayed only 10 years after the construction possibly caused from no maintenance for the periods. The reason of no maintenance is due to the misunderstandings on wood durability against wood-decaying fungi. Some civil-engineers and architectures understand "durable species" means "absolutely decay-durable species." They recently like to use durable wood species imported from abroad instead of domestic wood treated with preservatives because Japanese policies and civic insistences avoid to use wood preservatives to maintain natural environment and human health. This paper deals with the details of the typical decay damages of wooden bridges.
S Doi, T Sasaki, Y Iijima


Thermal modification of non-durable wood species 2. Improved wood properties of thermal treated wood
1998 - IRG/WP 98-40124
Properties of wood treated in a new heat-treatment process called the PLATO-process have been studied. Several wood species have been treated using this new thermal modification process using a range of process conditions (mainly time and temperature). In this study the characteristics of the treated wood were determined using samples from whole planks treated on pilot plant scale. The modified chemical structure of the wood after treatment results in a product with improved properties. The most important properties of wood, strength, dimensional stability and durability, were determined before and after the heat-treatment. The examined wood species showed a minor loss of strength after treatment. The correlation between the hygroscopicity of the treated wood in moist conditions and the dimensional stability has been studied. Depending on the applied process conditions the hygroscopicity of the treated wood decreased. The hygroscopicity was reduced by 40% and the dimensional stability appeared to have an improvement, ranging to 50%. The durability after heat-treatment was substantially improved.
B F Tjeerdsma, M J Boonstra, H Militz


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


The effect of woody and non woody plants extractives on microbial resistance of non-durable species
2006 - IRG/WP 06-30392
The effect of Elm (Zelkova carpinifolia), Oak (Quercus castanifolia), Mulberry (Morus alba), Ash (Fraxinus excelsior) as woody plants, Rose (Rosa damascene) and Fumitory (Fumaria sp) as non woody plants extractives on durability of Beech (Fagus orientalis), Maple (Acer insgin), Alder (Alnus subcordata), and Lime (Tilia sp) were studied. First wood species having extractives were cut to small pieces and then were chipped and milled, by using Tappi (T20403-76) standard. Acetone and Methanol solvents were used to extract soluble materials from wood durable species, and their extractives percentage were measured. Also wood specimens of perishable species such as beech measuring 0.5 x 1 x 5 cm were prepared. The fungus (Trametes versicolor) was selected and taken from the forest (Darabkola in Mazandaran state). Solvated extractives were injected into non-durable wood species by negative atmospheric pressure and then treated wood specimens oven dried at 50 o C. Then all treated and untreated wood blocks again oven dried, cooled, sterilized, and exposed to the fungus. Milled wood (with and without extractives) as control specimens were poured into Pyrex tube glasses, oven dried, cooled, weighed, sterilized and also exposed to the fungal attacks. At the end of experiment (after 6 weeks) mycelium were removed from surfaces of exposed wood samples and wood blocks oven dried, cooled, and weighed. Results showed that weight losses of all treated wood species except Lime significantly decreased. Other results indicated that Alder and Lime absorbed solvent more than Beech and Maple. However, solvated extractive of Mulberry significantly was inserted less than other wood extractives.
S M Kazemi, A Hosinzadeh, M B Rezaii


Non-pressure preservation technique of five less durable timber species – Kadam (Anthocephalus cadamba), Shimul (Bombax ceiba), Pithalu (Trewia nudiflora), Am (Mangifera indica) and Boroi (Ziziphus jujube) of Bangladesh
2006 - IRG/WP 06-40322
Wood is a versatile renewable resource, which has been extensively used as a reliable construction material as well in furniture ever since the beginning of civilization. The Major disadvantage of wood is its susceptibility to biodeterioration by fungi, insects and bacteria. In tropical countries like Bangladesh, fungi is the most significant of these biodeterioration agents. Kadam (Anthocephalus cadamba), Shimul (Bombax ceiba), Pithalu (Trewia nudiflora), Am (Magnifera indica), and Boroi (Ziziphus jujube) are five, local and available, useful but less durable timber species of Bangladesh. The heartwood of these timber species is more or less resistant to decay and insects, but sapwood faces quick deterioration while exposed to moisture and wood enemies. On the other hand, wood can be protected from attacks from these enemies with the appropriate preservative treatment, by reducing or changing the form of its food toxic to wood enemies. So, appropriate preservative treatment is required to increase the durability of these timber species. The study of chemical preservative treatment of these five timber species has been undertaken using a mixture of Chromate-copper-boron (CCB) at 2:2:1 ratio with four different concentrations of 4, 6, 8 and 10% and different treatment durations of 8, 16 and 24 hours by non-pressure dipping method. It has been observed that Pithalu showed comparatively higher preservative retention than other four species, which indicates that Pithalu is a permeable and diffuse specie for dipping method. A preservative penetration test provided the information that air dried wood samples using 10% preservative concentration with 8 hour and 24 hours duration of dipping gave the best result for copper, while 10% preservative concentration with 24 hours duration used on green wood has shown the best result for boron penetration. The major physical properties of wood viz., moisture content, density and shrinkage have also been studied. Anthocephalus cadamba showed a lower density, while Ziziphus jujube had a higher density. Bombax ceiba and Trewia nudiflora are very close to Anthocephalus cadamba and Magnifera indica is very close to Ziziphus jujube with respect to the moisture content. Bombax ceiba, Trewia nudiflora and Magnifera indica showed all moderate positions with respect to density.
G N M Ilias, A H Kabir, F Begum, M F Alam


Feasibility study on three furfurylated non-durable tropical wood species evaluated for resistance to brown, white and soft rot fungi
2008 - IRG/WP 08-40395
Furfurylation can protect non-durable wood species against biological degradation, but the method used today cannot fully protect the heartwood of Scots pine due to insufficient penetration. In order to test alternative wood substrates for furfurylation, three Malaysian grown wood species (Kelempayan, Rubberwood and Sena) were furfurylated and subjected to soil block decay testing. Their performance was compared to furfurylated Scots pine and furfurylated Beech modified using the same process. In addition, treatment characteristics were evaluated. One of the species tested, Kelempayan, seems to be a promising substrate for furfurylation. Kelempayan is easy to impregnate in both sap- and heartwood, and a 50% higher weight gain was reached using equivalent amounts of impregnation solution compared to Scots pine. Sena, Rubberwood and Beech returned weight gains 40-60% lower than Scots pine. Decay protection was largely comparable at equivalent weight percent gains for all wood species tested, although differences appeared. Generally, a weight gain of approximately 25% by furfurylation seems to offer good protection in the chosen soil block test.
T Mark Venås, A H H Wong


Field Tests of naturally Durable North American Wood Species
2008 - IRG/WP 08-10675
There has been little field test performance data published on North American naturally durable species in general, and no published data on second growth material in particular. Yellow cedar (Callitropsis nootkatensis), western red cedar (Thuja plicata), eastern white cedar (Thuja occidentalis), and three wood species reputed to be moderately durable were installed in ground-contact (stakes) and above-ground (decking) field tests at test sites in British Columbia and Ontario, Canada and Florida and Hawaii, USA between the Fall of 2004 and Spring 2005. Where possible old growth and second growth material, with and without sapwood, were obtained and used in the testing. Results from ground-contact field stakes and above-ground mini-decks after 3 years exposure are presented. The test site with the fastest ground-contact decay rate was Florida. The fastest above-ground decay rate was seen in Hawaii. In general, yellow cedar was the most decay resistant, followed by the other two cedar species, then the three other species. There was no appreciable difference in decay resistance between heartwood samples from old-growth and second-growth western red cedar, yellow cedar, and larch (Larix occidentalis).
P E Laks, P I Morris, G M Larkin, J K Ingram


Wart Morphology can Distinguish White Cypress Pine from the Less Durable Species, Black Cypress Pine
2009 - IRG/WP 09-20406
White cypress pine (Callitris glaucophylla) wood is durable enough to be used outdoors, but occasionally there are reports of its premature failure in ground contact, which may be due to its substitution by the less durable species, black cypress pine (C. endlicheri). It has been difficult to prove this, however, because the woods of both species are very similar in structure and cannot be separated using conventional anatomical features. This study examined whether differences in the size and morphology of warts on tracheid walls in the two species could be used to identify them. There were significant differences in the height, width and shape of warts in the two species, but there was considerable overlap in the distribution of these parameters between specimens. Warts in C. endlicheri were more likely to be bent-over near their tops than those in C. glaucophylla, and the angle bending of warts was greater in C. endlicheri. Quantification of these parameters produced complete separation of multiple specimens of the two species, and could potentially be used to help determine whether premature failure of C. glaucophylla heartwood in ground contact is the result of its substitution by C. endlicheri.
R Heady, R Cunningham, P Evans


Above Ground Field Evaluation and GC-MS Analysis of Naturally Durable Wood Species
2012 - IRG/WP 12-10764
Nine wood species are being evaluated in above ground field studies in Mississippi and Wisconsin. Candidate naturally durable wood (NDW) species are being rated at yearly intervals for resistance to decay, cupping, and checking. Field ratings after 12 months exposure are presented. To date, Paulownia tomentosa (PAW) and southern yellow pine (SYP) are least durable and cedars are the most durable in above ground exposure. Wood samples are being taken from the deck-boards and subjected to chemical analysis using GC-MS. Fatty acids from NDW species were extracted, derivatized, and analyzed along with commercial fatty acid methyl ester (FAME) standards. With few exceptions, results indicate that FAMEs are more abundant in NDW species. However, preliminary bioassays found no inhibition of select wood decay fungi by FAMEs at naturally occurring concentrations.
G T Kirker, A B Blodgett, S T Lebow, C A Clausen


Use of the durable species Coast Redwood as a reference system for field testing of Wood Protection systems
2012 - IRG/WP 12-20486
Data is provided and discussed for a number of field exposure tests where the naturally durable wood species Coast redwood, Sequoia sempervirens, was included along with untreated pine and standard preservative treatments. In general, there is potential for higher variability of results with this naturally durable species, but it does suggest that redwood can be a useful reference material for testing systems for above ground applications, especially where long-term decay performance may not be as critical as overall product quality. Comparative performance of products to redwood heartwood at test sites with different climate indices and with different test methods may provide additional useful data on the relative performance of systems than when compared to only untreated pine sapwood and standardized preservative systems.
A Zahora, A Preston, L Jin


Transferable Durability: Enhancing decay resistance of non-durable species with extractives from durable wood species
2013 - IRG/WP 13-10808
Extractive content and composition is a vital component of naturally durable woods; however, variability in extractives can limit their usefulness in the field. Two extractive-free, non-durable wood species were pressure treated with ethanol-toluene extractives from 8 durable wood species. Extracted Southern pine, Paulownia and unextracted Southern pine blocks were treated and challenged in soil bottle experiments with four common wood decay fungi. Weight loss from fungal degradation of the extractive-treated blocks was compared to untreated controls. Results indicated that in some cases, treatment with extracts from durable wood species decreased the percent weight loss from exposure to decay fungi. Chemical analysis of extractives from these durable and non-durable woods was performed using GC-MS and chemical components were compared. Several unique compounds were found in the more durable species compared to less durable species.
G T Kirker, A B Blodgett, S Lebow, C A Clausen


GC-MS Characterizations of Termiticidal Heartwood Extractives from Wood Species Utilized in Pakistan
2016 - IRG/WP 16-10857
Wood species that exhibit innate tolerance to wood destroying organisms such as termites are considered to be naturally durable. This durability can, in part, be due to the complex chemical compounds in the heartwood of naturally durable wood species. We examined the effects of varying concentrations of heartwood extractives on the subterranean termite, Reticulitermes flavipes from four wood species from Pakistan (Dalbergia sissoo, Cedrus deodara, Morus alba and Pinus roxburghii) as well as Teak (Tectona grandis). Termites showed increasing levels of mortality with increasing concentration of heartwood extractive when exposed to extractive treated non-durable southern yellow pine (SYP) blocks in a force feeding test compared to SYP blocks treated with water or solvent (ethanol: toluene) only. Characterizations of heartwood extractives were performed using Gas Chromatography-Mass spectrometry (GC-MS). Chemical profiles were prepared for each wood species’ extractives and are discussed relevant to their termiticidal properties. Future work will focus on further isolation of bioactive compounds or synergistic groupages of bioactive compounds from these and other wood species for use as environmentally friendly insecticides/termiticides for wood and wood based materials.
M E Mankowski, B Boyd, B Hassan, G T Kirker


Coula edulis baill an unknown wood species as an alternative to the main durable wood species used in Gabon
2019 - IRG/WP 19-10945
The Congo Basin hosts an exceptional biodiversity of trees, flora and fauna. However, the immense natural heritage of the forests in this area is increasingly threatened by many anthropogenic factors, due to selective exploitation of certain wood species. In Gabon, whose ecosystem is representative of this area, the forest represents nearly 80% of the national territory. Only a minority of wood species is exploited because of their high market value (Ageos, 2015). The direct consequences of this selective exploitation are the decrease of the disponibility and even the eventual disappearance of certain wood species associated to the fast-growing international tropical timber markets. This is the case for kevazingo, which is classified as an endangered species and therefore prohibited from exploitation. In addition to these main exploited species, several less known species are available in Gabon. This is the case of the Gabonese hazelnut tree (Coula edulis baill), whose wood is used by local populations for its longevity because of its resistance to fungi, insects and more particularly termites. It is used to make forge coal and is used in the construction of huts such as posts and lintels (Moupela C et al, 2010-2013). In this context, it seemed interesting to study more in detail this species, having for the moment been the subject of little scientific investigations. The aim of this study was to investigate the natural durability of Coula edulis and the reasons of this latter one based on wood chemical composition. For this purpose, durability tests were carried out in Petri dishes on native and extracted samples of heartwood towards brown rot (Poria placenta and Coniophora puteana) and white rot (Coriolus versicolor and Pycnoporus sanguineus) fungi showing that unextracted samples presented higher durability to fungi. Fungal growth inhibition tests carried out with different concentrations of extractives confirmed their important fungicidal effects. Percentage of the different wood polymers and chemical composition of wood extractives were evaluated to find correlation between durability and wood chemistry. Results indicated that natural durability of Coula edulis could be explained by several reasons like the high density and hydrophobicity of its wood as well as its high lignin and extractives contents. Chemical analysis performed on extractives by GC-MS indicated the presence of gallic acid, quercetin and tannins.
C S A Bopenga Bopenga, S Dumarçay, P Edou Engonga, P Gerardin


Above-Ground Termite Resistance of Naturally Durable Species in Ontario and Mississippi
2022 - IRG/WP 22-30767
A collaborative above-ground protected termite field test was initiated by FPInnovations and the USDA Forest Service at sites in Ontario and Mississippi. The aims of the experiment were to compare the rate of attack in protected, above-ground exposures by the subterranean termite species, Reticulitermes flavipes, between northern (Ontario) and southern (Mississippi) test sites and to generate performance data to understand the resistance to termites of selected naturally durable North American species. After 5-years of exposure, termite attack was greater in untreated pine sapwood controls in Mississippi than Ontario, though similar in the naturally durable species and the MCA-treated reference. All naturally durable heartwoods evaluated were more resistant to termites than untreated controls, and less resistant than the MCA-treated reference. More time is needed to define the service life expectations of naturally durable heartwood species and to determine whether there are differences in their termite resistance.
R Stirling, M Mankowski


Field performance of wood preservative systems in secondary timber species
1997 - IRG/WP 97-30152
The objective of this ongoing study is to evaluate the performance of new, potential, and standard wood preservative systems in secondary North American timber species. Eleven preservative systems were evaluated in this study - ACQ Type B, Copper Citrate 2: l, CDDC, chlorothalonil/chlorpyrifos, copper-8-quinolinolate, tebuconazole/chlorpyrifos, RH287, propiconazole/chlorpyrifos, copper naphthenate, CCA. and creosote. Field evaluations are being performed with ground contact field stakes and termite-specific testing in Hawaii, along with laboratory soil bed tests. The major wood species used with all the systems and evaluation methodologies are loblolly pine, northern red oak, tulip poplar, and cottonwood. More limited evaluations (field stakes only) are being conducted with eastern hemlock, red maple, and sweetgum. Information is presented from laboratory soil bed, field termite, and field stake evaluations. There is good correspondence between soil bed and field stake results. The more highly developed preservative systems and those in an AWPA P9 Type A oil carrier tend to perform better, and there can be a strong affect on performance from the wood species.
P E Laks, K W Gutting, R C De Groot


IRG/COIPM INTERNATIONAL MARINE TEST - to determine the effect of timber substrate on the effectiveness of water-borne salt preservatives in sea-water. 2nd Interim Report
1981 - IRG/WP 477
Three reference wood species - Alstonia scholaris, Fagus sylvatica and Pinus sylvestris, untreated and treated with 3%, 6% and 10% CCA and CCB solutions were supplied to all participants for submergence at local sites. Regular examination of samples is being carried out - 6 months, 12 months and then annually for 7 years.
R A Eaton


Coding scheme for samples for IRG world-wide co-operative field experiment
1975 - IRG/WP 360
Each sample has been given a number containing six digits (eg 16 23 05). The first 2 digits indicate the country and person supplying the timber, the second 2 digits indicate the species of timber, and the last two digits indicate the treating concentration. All samples which end with the numbers 26 to 50 are to be placed in one site in the United Kingdom, probably at the Imperial College site at Silwood. All the other samples will be returned to the persons in the following list according to the code number indicated.
R Cockcroft


The most important characteristics of some species of the genus Hypoxylon found in Serbia, Yugoslavia
1977 - IRG/WP 165
M Petrovic


IRG/COIPM INTERNATIONAL MARINE TEST - to determine the effect of timber substrate on the effectiveness of water-borne salt preservatives in sea-water. Progress Report 10 from Naos Island, Panama
1980 - IRG/WP 462
Blocks of 3 wood species, Beech (Fagus sylvatica), Scots pine (Pinus sylvestris) and Alstonia (Alstonia scholaris) were exposed at site number 12 at Naos Island, Panama on March 8, 1978 by John R. DePalma. The arrangement of the panels in the exposure site is as shown in Figure 1.
D W French


IRG/COIPM INTERNATIONAL MARINE TEST - to determine the effect of timber substrate on the effectiveness of water-borne salt preservatives in sea-water. Progress Report 8: Panama test results
1980 - IRG/WP 458
Summary of damage to ITRG test stakes by pholadidae and teredinidae at the Panama test site - 8 Mar. '78 to 11 Oct. '79
J R De Palma


Penetration analysis of two common bamboo species - borak and jawa of Bangladesh
2002 - IRG/WP 02-40247
Preservative treatment of two bamboo species, namely borak (Bambusa balcooa Roxb.) and jawa (Bambusa salarkhanii Alam) was carried out with chromated copper boron (CCB) preservative by dipping method. The variation in preservative penetration between the two different species was determined. It was found that preservative penetrates into borak quicker than into jawa and easier into air-dried bamboo than into green one.
M O Hannan, A K Lahiry, N M Islam


The susceptibility of 35 Amazon wood species to Cryptotermes brevis (Walker)
1982 - IRG/WP 1160
Laboratory tests were carried to evaluate the susceptibility of 35 Amazon hardwoods to Cryptotermes brevis (Walker). The results were analysed statistically and showed that five wood species were non resistant, nine were resistant and the other twenty-one in between those classes of resistance.
M D Canedo


Next Page