Your search resulted in 89 documents. Displaying 25 entries per page.
A critical review of the AWPA standard method (M12-72) for laboratory evaluation to determine resistance to subterranean termites
1986 - IRG/WP 1298
The American Wood Preservers' Association standard (M12-72) for evaluation of candidate wood preservatives against subterranean termites is reviewed and suggestions for revision are made. The most serious flaws in the current test procedure involve a failure to recognize inter- and intraspecific variation and a lack of quantification of test results.
J P La Fage, M Jones
Soil blocks versus field test for evaluating and standardizing wood preservatives: A commercial view
1994 - IRG/WP 94-20024
On the basis of technical considerations, experience, costs and applicability, the author concludes that the soil block test and other laboratory tests have little meaning in a wood preservative standardization process and almost no merit in the commercialization of a wood preservative system. Field tests at sites known to be aggressive to preservative treated wood are strongly recommended.
W S McNamara
Protection of wood blocks treated with Trichoderma isolates selected on the basis of preliminary agar screening studies
1996 - IRG/WP 96-10154
Previously reported results of agar interaction screening studies for biocontrol agents of wood decay basidiomycetes showed two Trichoderma viride isolates, killed 16 of 19 target fungi (Tucker and Bruce, 1995). Testing of these isolates in wood was required to assess their performance at preventing decay of wood blocks. Standard testing of chemical wood preservatives is used to determine the toxic concentrations of preservative required to protect the wood against decay by basidiomycetes. As no ratified standards for testing biocontrol agents exist, two amended wood block testing standards were used to assess the two most effective Trichoderma isolates selected on the basis of preliminary agar screening studies. An agar based system similar to European Standard EN 113 (1980) and a soil block test based on the AWPA Standard 1413 (1977) were used with Scots pine and Sitka spruce pre treated with Trichoderma. Results indicated that wood blocks treated with Trichoderma isolates (T60) and (T110) were completely protected against decay by all the basidiomycetes tested irrespective of form of inoculum used (spores or mycelium) or timber species. Implications of the results for the use of agar plate interaction studies for screening biocontrol agents for subsequent use in wood block testing are discussed.
E J B Tucker, A Bruce, H J Staines
Post-layup protection of mass timber elements in above ground protected exposures: 2-year results
2022 - IRG/WP 22-30766
Mass timber has seen increased use as a building material for low and mid-rise construction in recent decades. The durability of mass timber elements has not been fully examined and the effects of wood destroying organisms on this these materials merits attention. The effectiveness of currently labeled soil termiticides and passively applied biocides at post-construction or as remedial agents needs to be evaluated for mass timber used in structures, particularly in areas with elevated risk of termite attack. The ability of soil insecticidal drenches or spray-on insecticide/fungicide treatments for protecting mass timber in service was assessed with a modified AWPA Standard E21 above-ground test using three ply Douglas-fir or southern pine cross-laminated timber as well as Douglas-fir mass plywood panels. Samples of each material (305 x 102 x 102 mm) were installed in an above ground protected test at the Harrison Experimental Forest (HEF) (Saucier, Mississippi) in September, 2019. Six replicates of five treatments including soil termiticide, no treatment, spray-on borate at initiation, borate rods and remedial treatment, using spray on borate of attacked material after two years, were tested. Samples were left undisturbed for two years and then examined and rated. Near surface moisture content increased to levels approaching the fiber saturation point over the two-year non-disturbance period. Untreated control samples were attacked by both decay fungi and termites. Samples treated with borates at test initiation showed limited decay or termite attack. Soil termiticide treated plots showed no sign of termite attack, but some samples had heavy decay compared to non-soil termiticide treated plots.
M E Mankowski, T G Shelton, G T Kirker, J J Morrell
Proposed method for out-of-ground contact trials of exterior joinery protection systems
1981 - IRG/WP 2157
Methods for testing the efficacy of preservative treatments for exterior joinery are described using the format of a European Standard. Commercially used treatments applied to jointed test units (L-joints) which are then protected by conventional finishes are exposed to normal outdoor hazards out of ground contact. Assessment is made a) by determining eventual failure through decay and b) by destructive examination of replicate treated and untreated units, after increasing time intervals, rating comparative performance in terms of wood permeability increase and the progress of microbial colonisation.
J K Carey, D F Purslow, J G Savory
JWPA method for testing effectiveness of surface coatings with preservatives against decay fungi
1981 - IRG/WP 2164
In 1979 JWPA established a new method for testing effectiveness of surface coatings in accordance with practical use of preservative-treated lumber. Comparing the new testing method with JIS A 9302, a few new trials - size of wood specimen, weathering procedure, and decay-test procedure - are incorporated.
A proposal for an international wood preservation standard
1994 - IRG/WP 94-20031
Two factors are driving the need for an international wood preservation standard. First, the global need to use our natural resources more wisely and second, the movement towards free trade exemplified by the General Agreement on Tariffs and Trade. The International Research Group on Wood Preservation is the ideal organisation to undertake the task of developing such a standard. This paper is intended to start this process. It attempts to bring together the best points of a number of national and international standards into a uniform format. Preservative penetrations and retentions for each commodity would be based on the hazard class/use category, the climate zone, the biological area, the natural durability of the heartwood of the species used, the service life required and the consequences of failure. The outline standard presented borrows heavily from the new European Standard and is presented as a possible starting point for the development of an international standard.
P I Morris
CEN Draft (38 N 460E) Standard: Test method for determining the protective effectiveness of a preservative in the marine environment
1986 - IRG/WP 4132
This European Standard describes a marine test method which provides a basis for asseasing the effectiveness of a wood preservative used to prevent attack of timber in sea-water by marine borers. The method is only suitable for testing preservatives which are intended to prevent attack by marine wood boring organisms of treated timber for use in more or less permanent contact with sea-water. It is not suitable for assessing the effectiveness of preservatives against micro-organisms. The main objective of the method described is to evaluate the relative effectiveness of a wood preservative applied by vacuum/pressure impregnation. For this reason permeable timbers are used throughout so that the protective efficacy of various retentions of the preservative can be determined. However, it is recognized that modifications of the method may be used for other purposes, e.g. to determine the relative efficacy of a preservative treatment or to determine the natural durability of the heartwood and sapwood of a selected timber species. The method is primarily intended for testing in temperate waters where Teredine and Limnoria borers dominate. However, it is also capable of being used in tropics where attack by Pholads and specific Crustacean borers may be very destructive. It has to be considered that the test has to be run for a minimum period (usually for 5 years or until the point of failure) before any interpretation of the results can be made. Variations in the test conditions can be expected from one test site to another depending on temperature, salinity, population density of the various borer species etc. This will inevitably influence the general rate of attack. However, by comparing the results obtained for samples treated with the test product with those obtained with a reference preservative and those obtained with untreated control samples, the relative protective effectiveness of the product tested can be evaluated.
Wood preservation in France. "Bois plus" chain of quality. Description of the scheme early 1989
1989 - IRG/WP 3519
1989 - description of the French "CTB-BOIS PLUS" homologation scheme...
Mycological testing of plywood and board materials. Part 1: Review of information supplied by IRG members
1978 - IRG/WP 284
In December 1975 IRG members were asked for published information, information of current work in progress and views on mycological test methods for board materials. The object was to stimulate discussion and possibly establish a joint research effort within IRG in order to establish a meaningful test with reproducible results.
C R Coggins
Proposed standard laboratory method for testing fungicides for controlling sapstain and mould on unseasoned lumber
1977 - IRG/WP 292
This laboratory method is for determining the effective concentration, or concentration for zero growth (CGo), for fungicides or preparations of fungicides which are potentially useful in protecting packaged or unseasoned lumber in storage and shipment from biodeterioration by sapstain fungi and moulds. The test is rapid and may be completed in three weeks and gives a good indication of the toxicity of a chemical against sapstain fungi and moulds.
A J Cserjesi
Wood preservation in the USA
1982 - IRG/WP 3215
This report is a comprehensive survey of the status of the wood preservation field in the U.S.A. at the start of the 1980s. The importance of wood preservation is discussed and its industry described. Various statistics and analyses regarding the use of treated wood have been compiled. Both pressure and non-pressure applications have been covered, as well as remedial treatments and pest control operations. A list of American organizations concerned with wood preservation have been included, together with the various research laboratories which are studying the biodeterioration of wood and its protection. Information is given on the standards and specifications which are in current use. The report, which is fully referenced, ends by suggesting possible future trends for wood preservation in the U.S.A.
D D Nicholas, R Cockcroft
The effectiveness test of chemicals against Serpula lacrymans
1984 - IRG/WP 2222
The effectiveness tests of wood preservatives against Serpula lacrymans were conducted in accordance with Japan Industrial Standard A 9302 and Japanese Wood Preserving Association Standard No. 1. Also, the soil treatment test against this fungus was carried out with two chemicals. The preservatives tested without Creosote oil (out of JIS) had sufficient preservative effect against Serpula lacrymans. Flutolanil for soil treatment had full effect for suppression of the hyphal growth of Serpula lacrymans onto the soil surface.
Climate indices at work: Above ground decay L-joint tests (EN 330 and AWPA E9) at two sites 12000 km apart and with Scheffer climate indices of 60-65 and 300-330
1996 - IRG/WP 96-20095
Matched sets of Scots pine sapwood (Pinus sylvestris) L-joints were exposed above ground at two field sites for approximately five years. One site, at Garston, Watford, UK has a climate index between 60 and 65 while the other, close to Hilo, HI, USA has an index between 300 and 330. The joints were treated with a range of organic solvent treatments applied either by three minute dip immersion or by double vacuum. Untreated joints were installed at each site as control material. All samples were assessed at approximately annual intervals at both sites. After five years, decay at the Hilo site is well advanced with failure apparent in many joints, both untreated and treated. As would be expected given the climatic differences, decay at the Garston site has progressed more slowly than in Hilo. Differentiation in treatment performance was apparent after one year's exposure in Hilo with similar differentiation becoming apparent after five years' exposure in Garston. This acceleration correlates well with the difference in Climate Index for the two sites as calculated using the Scheffer method. Encouragingly, the performance ranking of the different treatments at the two sites was very similar. The results of this test suggest that the concept of using high decay hazard sites for field testing of treated wood products for use in above ground situations can provide meaningful results in a short period, and may offer a timely and realistic alternative to relative preservative testing to that achieved in laboratory test regimes. The results also show that above ground field testing at both of the sites included provide valuable information on preservative performance, and this information is likely to provide a greater degree of realism than is possible using pure culture laboratory test procedures.
A F Preston, K J Archer, D M Roberts, J K Carey, A F Bravery
Evaluation and approval of wood preservatives in the Nordic countries
1988 - IRG/WP 2311
This paper reviews the system for evaluating and approving the efficacy of wood preservatives for industrial use currently in force in the Nordic countries Denmark, Finland, Iceland, Norway and Sweden.
B Henningsson, J Jermer
Report of activity of CEN/TC 38: Test Methods for Wood Preservatives
1987 - IRG/WP 2287
Rapport sur l'activité du CEN/TC 38 "Méthodes d'essais des produits de préservation du bois"
1982 - IRG/WP 2188
Leaching of CCA from Pinus patula during marine trials in the southern hemisphere
1991 - IRG/WP 4167
Pinus patula stakes were treated with CCA to retentions of 31 kg/m³ salts, and were sited in the sea of Port Alfred, South Africa, for two years. Samples were then removed to the laboratory and analysed as before for copper and arsenic. Prelimiary data showing CAA losses from these stakes in the marine environment showed that CCA was longitudinally leached from them, and was also transversly redistributed in them.
G D Shelver, C D McQuaid, A W W Baecker
How to determine what is a realistic emission from treated wood - basic reflections
1998 - IRG/WP 98-50105
Emissions from treated wood occur by evaporation and by leaching. Up to date by far more experience exists on leaching tests than on evaporation test. The methods applied will be of interest to give answers to the questions about the quantity of possible emissions. Standardisation on leaching started very early. One of the first attempts to quantify the effect of leaching on the remaining efficacy was the German DIN 52176-2 (1941) which was the basis for EN 84 first published by CEN in 1978. A specific German standard for the determination of leachates was published in 1972 (DIN 52172-2), however, the viewpoint was still the efficacy of wood preservatives. With respect to pollution of the environment EN 1250-2 (1995) has to be mentioned, however, this is more or less only a modification of EN 84 and as such not very satisfactory. Evaporation tests started as late as in the 50th mainly in connection with fluorides and later with PCP. Examples for a standard to determine the remaining efficacy are the German Pre-Standard DIN 52172-3 (1971) and EN 73, based on the German standard and first published in 1978. A specific standard for emissions is EN 1250-1 (1995). The reflections presented in the paper consider evaporation as well as leaching tests where the general requirements and the statements to the kind of specimens and to the treatment apply to both types of emissions at the same time. For the test procedure itself, however, different methods are needed.
H Willeitner, R-D Peek
Evaluation and approval of wood preservatives in Japan
1988 - IRG/WP 2303
Japanese standardized decay test methods, performance requirements and approving system are briefly described. JIS (Japanese Industrial Standard) A 9302, which is related to a testing method for evaluating effectiveness of wood preservatives when applied to pressure treatment, is fundamentally a sand-block laboratory test method. According to performance requirements in JIS A 9201, mean percentage weight of treated wood specimens should be less than 10% and 20% of that of untreated specimens against Tyromyces palustris and Coriolus versicolor respectively. JWPA (Japan Wood Preserving Association) Standard 1 covers a testing method for assessing efficacy of wood preservatives for superficial treatment. Test procedure is basically the same as JIS A 9302, although some major modifications are adopted with regard to shape and size of wood specimens, weathering cycles and the length of forced decay. Qualitative standards require that a candidate chemical should inhibit decay keeping mean percentage weight loss of treated wood specimens less than 20% of that of untreated ones in any case as prescribed in JWPA Standard 7. Results obtained by the above methods are well discussed together with other information by Japanese Examining Board of Wood Preservatives to approve a candidate chemical as a wood preservative when an application form is submitted to the board. And then the final decision will be made by JWPA [or JTCA (Japan Termite Control Association)] if the applied chemical is acceptable for approval or not.
Practical consideration in developing an international hazard class standard: The hazards and risks
1996 - IRG/WP 96-20091
This paper discusses the concept of hazards and risks in relation to the way in which the hazard class philosophy may be used for international standardization. The difference between hazard and risk is considered as a basis for a simple classification of biological hazards for timber in use based upon its service environment. The paper proposes that the moderating influences within a service environment may be regarded as risks and used to classify the severity of hazard. These risks depend principally upon geographical location (climate) and design features controlled by the specifier. It is concluded that a pragmatic and simple approach could provide the best opportunity for an international agreement.
R J Orsler
Transmission poles with sub-standard retentions protected by Field Liners outperform standard poles in service
1997 - IRG/WP 97-40095
Eucalyptus cloeziana 12m transmission poles were treated with sub-standard creosote retentions of 80kg/m3 and Field Liners were fitted to the poles before they were placed in service at Umbumbulu, Kwazulu Natal. Poles treated with standard creosote retentions of 130kg/m3 but without Field Liners were also placed in service in the same area. Core samples were taken from both groups of poles after 12 month's service and these were analysed for creosote content. It was found that the creosote retentions in the outer 10 mm of the sub-standard poles fitted with Field Liners had increased to mean values of 212.76kg/m3 and 219.24kg/m3 at depths of 100mm and 500mm respectively below the groundline. In contrast, the creosote contents of the standard poles without Field Liners had decreased to mean values of 49.20 kg/m3 and 52.64 kg/m3 at depths of 100mm and 500mm respectively below the groundline. It was also seen that the creosote had migrated under gravity from the tops to the groundlines of the poles. The difference in creosote retentions below the groundlines arose because the mobile creosote migrated out of the poles without Field Liners by leaching into the surrounding soil, whereas such mobility was physically arrested when creosote was confined to the wood in the subsoil sections of poles fitted with Field Liners.
M R Behr, G D Shelver, A A W Baecker
Incorporating insect behaviour in standard tests of wood preservatives - A possible way to reduce pesticide loadings
2000 - IRG/WP 00-20190
The application of wood preservatives to protect timber against insect infestation is common practice world wide. The effectiveness of wood protecting insecticides is usually determined in various standard tests. Depending on the target pest species and the test method, larvae of different developmental stages and sizes or adult insects are exposed artificially to the insecticide-treated commodity by placing them into or on to the material. The achieved mortality usually rates the effectiveness of the tested insecticide. Detailed observations have shown, that a lot of insecticides already show repellent effects to ovipositing females, or have ovicidal effects at much lower quantities necessary for larval kill. Furthermore, if the natural chain of behavioral steps in the insect, which lead to an infestation, are correctly analyzed, an interference and manipulation of the behavior should prevent or at least minimize the risk of an infestation and thus the needs for wood preservatives. Examples for successful manipulation of mating and host finding behavior are presented in this paper, using the old house borer Hylotrupes bajulus L., as a model: In the general biology of the old house borer, males emerge slightly before females and attract the later with a sex pheromone from the future breeding site. Experiments in the laboratory and semi field situations have shown, that pine wood, offered in no-choice bioassays, was most attractive to males, more than any other given alternative. Virgin females neither accepted pine nor the alternatives. Only the presence of males on pine wood increased its attractiveness to virgin females. Females of H. bajulus, when mated, readily deposit their eggs on any material (natural or artificial) if a suitable crack is presented. However, they hesitate to deposit eggs on timber treated with certain preservatives even in no choice situations. Additionally, it was found, that certain modern insecticides show ovicidal effects, preventing the larvae from hatching, rather than larvicidal effects. The observed host selection and mating behavior, together with general considerations of energy budgeting in insects suggests, that males rather than females of the old house borer most likely select new breeding sites. Interfering with host selection biology might therefore enable alternative control strategies against this destructive pest of structural timber. These strategies include: reducing the attractiveness of breeding sites for males, repelling host seeking males, trapping mate seeking virgin females, etc. Furthermore, ovicidal effects of wood preservatives are not yet considered in standard test. More detailed knowledge of the general behavior of wood boring insects will permit new ways to preserve timber without or with reduced amounts of pesticides. The effectiveness of behavior modifying chemicals can not be evaluated in existing standard test methods. An alternative test set up is presented in this paper.
H Hertel, R Plarre
Dimensional stability, biological resistance, and mechanical properties of phenol-resin-treated particleboard
1990 - IRG/WP 3622
Particleboards were treated with a low molecular-weight phenol-formaldehyde (PF) resin and their enhanced properties were evaluated. Besides dipping of particles in aqeous solutions of resin, and spraying of resin solutions before spray of the conventional phenol-formaldehyde resin for adhesive binder, one step treatment by spraying of the mixture of the low molecular-weight resin and the adhesive resin was also employed. After 2-hour boiling, the boards treated at 10% incorporated resin loading (IRL) retained 80% of their strength values in a dry condition. The internal bond strength increased with increasing IRLs, and the boards of 20% IRL showed twice of the value of untreated controls in the same level of board density. Treated particleboards resulted in a more dramatic reduction in the rate of swelling even at low resin loadings. Results obtained from accelerated laboratory tests on biodegradation suggested that incorporated resin-solids worked well to enhance decay and termite resistance of particleboards.
Y Imamura, H Kajita