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Accelerated ageing of preservatives in treated wood
1988 - IRG/WP 3476
New preservatives are tested in the laboratory and often in field tests before they are used commercially. Some preservatives, however, tested in the laboratory do not show the expected stability when used in service. The differences between laboratory tests and practical use can never be completely eliminated but must be minimized as far as possible by relevant testing methods. Studies of the effect of different accelerated ageing procedures on the chemical degradation and the wood preserving capacity of six different fungicides or combinations thereof have been carried out. Chemicals tested were tributyltinoxide (TBTO), tributyltin naphthenate (TBTN), furmecyclox, benzalkoniumchloride (AAC) + guazatin and pentachlorophenol. The ageing procedures included exposure of test specimens in a wind tunnel (according to EN 73), in an oven at 40°C, 60°C and 70°C, leaching (according to EN 84) and combinations of these procedures. The influence of the different accelerated ageing procedures on the chemical degradation and toxic effect of different fungicides was obvious and, for some procedures and chemicals, comparable with experiences from practice.
M-L Edlund, B Henningsson, B Jensen, C-E Sundman


Accelerated wood decay in a soil bed test under greenhouse conditions compared with a stake test under field condition
1991 - IRG/WP 2384
The rate of decay of oak, beech, Douglas fir, pine and spruce stakes in an outside test field were compared with the decay rate of the same species in a greenhouse soil-bed test. Strength loss after four and six months respectively was measured by determining the compression strength parallel to the grain. The results show that all species, strength loss in the greenhouse was 2 to 4 times higher than under field conditions. The rate of strength loss correlates with the rate of weight loss.
J E Polman, S G Michon, H Militz


Questionnaire: Facility for accelerated stake tests in unsterile soil
1981 - IRG/WP 2166
An acceptable name for this type of test facility has not yet been devised, but it has previously been referred to as a FUNGUS CELLAR or as a TROPICAL DECAY HOUSE. The attached pamphlet (What's New in Forest Research No.65) describes in broad terms the facility used for this purpose at FRI in New Zealand. Over the last two or three years several laboratories and commercial firms have installed so-called fungus cellars. At the 1981 I.R.G. Meeting in Sarajevo it was proposed that a survey be undertaken to obtain basic information on the various developments in this new area of biological testing. To this end, I shall be pleased if you complete the enclosed questionnaire and return it to: Dr J.A. Butcher, Forest Research Institute, Private Bag, Rotorua, NEW ZEALAND. A full report on this survey will be presented at the next I.R.G. meeting scheduled for Turkey in May 1982.
J A Butcher


Ground contact performance of wood treated by the MSU process
1990 - IRG/WP 3609
Environmental concerns have prompted a renewed interest in accelerated fixation schemes for CCA-treated wood. Results from stake tests of southern pine (Pinus sp.) treated using a conventional Bethell cycle are compared with matched stakes treated using the MSU Process. The effects of adding boric acid to the preservative formulation are also discussed. Differences among test plots are discussed.
H M Barnes, T L Amburgey, R W Landers


Natural durability of wood in ground contact - A correlation between field and laboratory tests
1985 - IRG/WP 2182
A field test is being carried out to evaluate the natural durability of 20 hardwoods. The resistance to decay and termite attack was evaluated in accelerated laboratory tests. The results of the field test after 6 years and 8 months indicate that there is not necessarily agreement between results from laboratory and field tests. It is pointed out that apart from the artificiality of the laboratory tests, a possible cause of the discrepancies can be the different performance of the same wood species in different test sites.
M S Cavalcante, G A C Lopez, R G Montagna, M E S Fosco Mucci


Relative performances of DNBP and CCA wood preservatives in accelerated decay tests
1988 - IRG/WP 3496
The effectiveness of 2-sec-butyl-4,6-dinitrophenol (DNBP) was compared with that of CCA. Test blocks of Pinus patula and Eucalyptus grandis were impregnated to precisely known retentions of approximately 3, 6, and 10 kg/m³ CCA and solvent-borne DNBP respectively. They were then challenged in decay tests comprising soil burial and exposure to monocultures of Chaetomium globosum, Coriolus versicolor and Coniophora puteana. Decay was monitored by determining weight losses produced in the blocks over 15 weeks. Overall, DNBP performed more successfully than CCA. Specifically, a toxic threshold of 7.4 kg/m³ DNBP was shown in soil-buried Eucalypt, whereas this wood failed in soil even when treated to 10.43 kg/m³ CCA. A mycocidal effect of DNBP on Coniophora puteana was detected. Comparing costs, effective wood preservation using DNBP was cheaper than using CCA, and such costs would be significantly lowered with the advent of less toxic water-borne DNBP.
W H Schnippenkoetter, L D Abraham, A A W Baecker


Comparison between agar-block and soil-block methods for wood-destroying Basidiomycetes
1992 - IRG/WP 92-2401
The object of this work is to compare these methods in order to provide some information to help in the choice between them. The comparison was made by a statistical analysis (factorial completely randomized design) and by a discussion about other aspects of each method. An evaluation of some fungi on attacking wood and a comparison between Picnoporus sanguineus isolated from carpophore and decayed wood were made. The results indicated that the loss of mass was greater in soil-block. Besides, the activity of the fungi in this method was more homogeneous than in agar-block. However the soil-block method presents some difficulties not found in the agar-block method. As related to the performance of Picnoporus sanguineus strains, the greater loss of mass occured when it was isolated from carpophore, no matter what method was used. These results give important indications about the biological characteristics and the source of the strains.
M B B Monteiro, S Brazolin, G Catanozi


Accelerated decay tests to investigate postulated effects of tannins on CCA efficacy in wood
1988 - IRG/WP 3497
Five groups of blocks (10 x 10 x 5 mm³) viz., Pinus patula, Pinus patula impregnated to 4% (w/w) tannin; Eucalyptus grandis, Eucalyptus grandis with natural tannins extracted; and extracted Eucalyptus grandis with tannins returned as above; were prepared. Blocks from each group were then treated to 0, 5, 10 and 15 kg/m³ CCA and challenged in four 15-week decay tests, viz., soil burial, and exposure to monocultures of Chaetomium globosum, Coriolus versicolor and Coniophora puteana. The effect of tannin on CCA efficacy was evaluated by weight losses produced. The antimicrobial effect of tannin in wood not treated with CCA was demonstrated. However, the presence of tannin did not effect CCA efficacy in wood at the preservative retentions tested, since weight losses in CCA treated Pine and Eucalypt, both with and without tannins, were similar throughout all tests.
U L Scherer, A A W Baecker


Accelerated decay tests on DNBP-treated Pinus patula and Eucalyptus grandis
1987 - IRG/WP 3441
Blocks (10 x 10 x 5 mm³) of Pinus patula and Eucalyptus grandis were impregnated to 0, 1.5, 3.0 and 4.5 kg/m³ 2-sec-butyl, 4, 6 dinitrophenol (DNBP). They were monitored microscopically and for weight losses over 16 weeks against monocultures of Coriolus versicolor and Coniophora puteana. Treated ministakes (10 x 10 x 100 mm³) and blocks in soil contact were similarly monitored to determine weight losses and microbial succession. Weight losses increased progressively. Final losses after soil burial were 10% in Eucalypt and 4% in Pine treated to 4.5 kg/m³ DNBP. Comparable figures after Coriolus exposure were 30% in Eucalypt and 7% in Pine. Both timbers were protected against Coniophora by 3.0 kg/m³ DNPB when weight losses never exceeded 3%. Pine was less colonised than Eucalypt and least isolates were obtained from samples containing most DNBP. Succession was always initiated by bacteria and molds after 2 weeks. Basidiomycetes colonised Eucalypt after 6 weeks but were not observed in Pine. Bacteria attached to wood by glycocalyces were observed to produce lysis troughs in S3 layers of cell walls of DNBP-treated samples of both woods.
L D Abraham, A A W Baecker


Window test. Direct testing of wood resistance to decay: A study of its fitness, its reliability and its accelerating factor
1984 - IRG/WP 2219
This is the results of an experiment using the window-test specimens, exposing the specimens to three different types of testing procedure: 1. Natural infestation in the open air; 2. Artificial infestation and exposure in the open air; 3. Artificial infestation in a green-house. The results show good similiraties of the three parallel tests in term of decay, and assess the reliability of the window-test, its fitness and particularly its accelerating factor.
G R Y Déon, L N Trong


In-house accelerated method for testing decay resistance of treated wood
2004 - IRG/WP 04-20286
Fungicidal compounds often change their effectiveness when they are incorporated into candidate formulations. For this reason fungistatic effectiveness needs to be re-evaluated as many times as the formula has been modified for better performance. To avoid multiple expenses, in-house fungistatic tests are essential. Our goal was to develop in-house usable, simple but reliable and reproductive procedure for testing decay resistance of the Sansin priming formulae without a need for special testing equipment. Our preliminary trials have proved that commercially available, heat processed wood pellet fuel can be used as an excellent substrate for growing certain wood rotting fungi. In contact with water wood pellets quickly disintegrate and convert into sawdust, gaining up to three times increase in volume. When wood pellets are wetted with water containing hydrogen peroxide, the vapors of this antiseptic kill non-desirable air-borne contaminants and protect the substrate from further contamination for as long period as peroxide remains in the substrate at sufficient concentration. When peroxide protected substrate is spawned with well-organized fungal organisms (for example true decay/test fungi), they will rapidly colonize the substrate and develop a powerful mycelial network capable of decomposing most of the natural fiber based materials. Treated and non-treated wood specimens were buried in spawned, hydrogen peroxide protected wood pellet fuel-based substrate and placed in transparent, perforated plastic containers to determine the effect of this procedure on rapid colonization and accelerated wood degradation. Parallel test was set up with specimens inserted in 150mm diameter dishes containing fungal cultures developed on the beer based agar medium. The results after 45 and 90 days of exposure to the brown rot causing fungus Gloeophyllum trabeum indicate that the weight loss in control blocks in containers was higher than in the dishes for 7 and 11 percent respectively.
N Vidovic


Co-operative studies on determining toxic values against wood-destroying basidiomycetes: Progress report to April 1990
1990 - IRG/WP 2357
This document reports progress on the co-operative study between nine laboratories, set up following the proposals contained in Document IPG/WP/2316 (1988). Results have been received from eight laboratories. Toxic values data have been established successfully for the test fungus Coniophora puteana with soil, malt agar and vermiculite methods and with the test fungi Gloeophyllum trabeum and Poria placenta in the soil method. With Coniophora puteana, there was less variation between the different methods carried out at the same laboratory than with the same method in different laboratories. Various options for further work are put forward for discussion.
J K Carey, A F Bravery


The movement of iron into field test stakes
1987 - IRG/WP 2284
Failed and sacrificial stakes recovered from the Westham Island field test site were examined for their iron content. Varying amounts were recorded, which were greatest in the failed stakes. The possible role of the iron taken up by the below ground portion of the stakes, in accelerating the decay process and/or the preservative leaching is under investigation. The reaction of the iron with the chrome azurol S reagent normally used to assess copper penetration, has important implications when measuring the penetration of chromated-copper and ammoniacal copper preservatives in field test material.
J N R Ruddick, P I Morris


Studies in an accelerated soil bed facility on the decay susceptibility of U.K. grown spruce and pine poles treated with copper/chrome/arsenic (CCA) by pressurised sap-displacement. Part 1: Setting up of soil beds and initial soft rot results
1990 - IRG/WP 2344
The paper describes the methodology used in the construction and early operation of an accelerated soil bed facility used to examine the decay susceptibility of U.K. grown Scots and Corsican pine and Sitka and Norway spruce treated with C.C.A. by high pressure sap-displacememt. The design and control of the facility as well as the preparation, soil exposure and soft rot decay analysis of quarter pole sections removed from full length poles is described in detail. The extent of soft rot in treated sections and controls was measured mechanically using a Pilodyn and also microscopically. In untreated control sections the Corsican pine was found to be the most susceptible timber to decay with the spruce species comparing favourably with Scots pine. All four treated wood species showed varying levels of C.C.A. penetration and subsequent resistances to decay. Thus while no soft rot decay was found in the treated regions of any of the wood species, internal soft rot was found beyond the penetration of the C.C.A. presentative. The implications of the findings for the testing of U.K. grown timber species for use as distribution poles after sap-displacement treatment with C.C.A. are discussed.
A Bruce, S D Hainey, G M Smith, B King, P D Evans


Proposal for further work on accelerated ageing
1988 - IRG/WP 2314
M-L Edlund


Field trial with poles of Scots pine treated with six different creosotes
1996 - IRG/WP 96-30115
In the middle of the 50's field trials with creosote-treated poles were started in France, Germany and Sweden. The trials were initiated by WEI (Western-European Institute for Wood Preservation). Six different creosotes were used and 40 poles per creosote were installed at each test field. Results after 39 years of exposure in Simlangsdalen, Sweden are reported. Poles treated with a heavy creosote were less decayed than poles treated with medium-heavy creosotes. Poles treated with a light creosote were most decayed.
Ö Bergman


Moisture content levels and decay of hemlock
1986 - IRG/WP 1287
As a model of decay conditions of wooden members in wooden houses, a decay test was set up in which samples of western hemlock (Tsuga heterophylla) under 4 moisture levels were examined. Each week the samples were weighed and if the weights indicated that their moisture contents were lower than the expected levels, distilled water was added. Every 8 weeks 3 samples from each condition were oven dried at 60°C for 48 hours, up to 48 weeks. After 48 weeks, 3 samples from each condition were oven dried every 16 weeks. The results obtained were as follows: After examining the samples for 96 weeks at 27°C, the mean weight loss of the hemlock samples kept at about 50-100% moisture content level was larger than those of the other levels. If the samples were dried every 8 weeks, the amount of decay in them was not significant. Decay was also not significant in the samples kept at approximately 20-30% moisture content level.
K Suzuki


Co-operative studies on determining toxic values against wood-destroying Basidiomycetes: Progress report to May 1989
1989 - IRG/WP 2339
This document reports progress on the co-operative study between nine laboratories set up following the proposals contained in Document IRG/WP/2316. Results have been received from two laboratories. Toxic values data have been established successfully using the test fungus Coniophora puteana but problems have been encountered with the other test fungi.
A F Bravery, J K Carey


How to Document the Performance of Super-Critical Treated Wood in above Ground Situations?
2005 - IRG/WP 05-20316
The paper presents practical experiences from the preparation of a new preservative treated wood product for introduction to the market. The product in question is Superwood™, which is treated with organic biocides using CO2 in a supercritical state as a solvent. The question is how to evaluate the performance of a new product such as Superwood™ in order to get an acceptance on the market and fulfil the formal requirements. In the European Union countries, the EN 599-1 is the standard that needs to be complied when approving a new product for the market, but it only focuses on the toxic limit against representative decay fungi according to EN 113. However, decay test, above ground and other forms of field tests are optional, this is not in line with the traditional test philosophy in the Scandinavian countries. The open question is to which extent treatment to the level of the toxic threshold value also ensures a long service life and expected performance of the treated commodity. Superwood™ is evaluated using a strategy, in which basic laboratory tests are done to get the toxic value (according to EN 599-1) and in addition a number of field tests are done including accelerated testing in the tropics. These tests are focussed on the evaluation of the performance criteria such as durability and service life and maintenance requirements. These questions must be answered by the producer without having a full record of performance test for their new products. A short status on the test performed on super-critical treated wood (Superwood™) is presented. Based on a comparison between field test in Scandinavia and in the tropical Malaysia a service life of more than 25 years for a specific supercritical treated product is estimated. It is stated that the existing European standardisation system is insufficient when it comes to service life prediction. A number of important questions need to be addressed by the European standardisation system as soon as possible because the market and the public opinion change quickly due to environmental concern.
N Morsing, A H H Wong, F Imsgard, O Henriksen


Japan's comments on ISO/DIS 12583-1/2
1996 - IRG/WP 96-20100
The paper describes an accelerated field test for the evaluation of timber preservative formulations against subterranean termites. The method has been adopted by the South African wood preservation industry as a screening method for the approval of wood preservatives for use under SA conditions. The method which is based upon the fungal cellar test offers a rapid means of evaluating the comparative performance of new wood preservative formulations in an environment that accurately reflects field conditions.
P Turner, D Conradie


On Donkioporia expansa (Desm.) Kotl. & Pouzar
1986 - IRG/WP 1285
Donkioporia expansa is found more often in houses than realised until now. Virulence tests according to EN 113 show not only an attack of oak, but also of other hardwoods and even soft-woods.
G Buchwald


Laboratory decay test of Burmese in and kanyin treated with three wood preservatives
1982 - IRG/WP 3210
Laboratory decay tests were performed on samples of In (Dipterocarpus tuberculatus Roxb.) and Kanyin (Dipterocarpus alatus Roxb. and Dipterocarpus turbinatus Gaertn f.) pressure treated with three wood preservatives - copper arsenic additive (CAA - a variation of ammoniacal copper arsenate), Arquad C-33 (a waterborne quaternary ammonium formulation), and tributyltin acetate (TBTA) dissolved in ethanol. Pressure treatments with each preservative involved a 0.5 - 1 hour vacuum followed by a 4 hour period of pressure. This resulted in a very variable treatment because of the inherent difficulty in treating these woods. The decay tests entailed a slightly modified form of the AWPA M10-77 standard soil-block test using three brown-rot and three white-rot fungi. The untreated In and Kanyin samples were moderately susceptible to decay though weight losses were very variable and some samples of Kanyin (usually the densest and least permeable) were naturally resistant. At the concentrations tested CAA was the most effective in reducing weight losses incurred in the soil-block tests. TBTA was successful in controlling decay caused by all but two of the test fungi. It is suggested that preservative retentions for TBTA conforming to those included in the Candadian standard for bis (tributyltin) oxide would exceed the toxic limit for all the fungi tested
J N R Ruddick, R S Smith, A Byrne


Studies on accelerated ageing procedures with TBTO-treated wood
1985 - IRG/WP 2244
The efficacy of various procedures for accelerated ageing of organotin based wood preservatives in treated wood has been investigated. It was found that leaching of the treated wood samples in water according to the European Standard EN 84 was not satisfactory for organotin based preservatives and is probably also unsuitable even for other types of organic solvent preservatives. Keeping tributyltin oxide (TBTO) treated samples in a heating cabinet at 70°C for five weeks, however, had a considerable effect on the breakdown of TBTO and the subsequent decay test. Therefore, an ageing procedure involving a heating period should be considered for all organic solvent wood preservatives. The investigation also confirmed that elevated temperatures accelerate the degradation of TBTO and that there is a strong correlation between the percentage of TBTO in the wood and its resistance against decay.
J Jermer, M-L Edlund, B Henningsson, W Hintze


Discussion of diiodomethyl p-tolyl sulfone (Amical® 48) as a fungicide for wood preservatio
1987 - IRG/WP 3425
The effectiveness of diiodomethyl-p-tolyl sulfone (Amical® 48) as a fungicide for preservation of wood is supported by a discussion of results from the literature and current research programs.
J M Stamm, K J Littel, F M H Casati, M B Friedman


In-ground performance of two formulations of chlorothalonil after five years of exposure at three test sites in Australia
1996 - IRG/WP 96-30101
Sapwood specimens of Pinus radiata D. Don and Eucalyptus regnans F. Muell. were each treated to three retentions of each of two preservative formulations (chlorothalonil in oil; chlorothalonil plus chlorpyrifos in oil) and installed in-ground at three field test sites in Australia. Specimens were treated with each formulation to achieve 3.2, 6.4 and 12.8 kg/m³ of chlorothalonil a.i. and 3.2 + 0.2, 6.4 + 0.4 and 12.8 + 0.8 kg/m³ of chlorothalonil plus chlorpyrifos a.i. For comparison, specimens of each timber species, treated to a commercial in-ground retention of a copper-chromium-arsenic (CCA) formulation, were also installed. Treated specimens (including controls) have been rated for their condition annually for attack by subterranean termites and fungal decay using a scale ranging from 4 (sound) down to 0 (failed). After five years of exposure, mean termite and decay scores for replicate test specimens at each site reveal that the performance of all three retentions of each formulation, particularly the two highest retentions, is comparable to CCA.
J W Creffield, T L Woods, N Chew


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