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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


An in-ground natural durability field test of Australian timbers and exotic reference species. Part 2: Progress report after approximately 13 years' exposure
1983 - IRG/WP 1189
The condition of heartwood specimens of Australian and exotic timber species after approximately 13 years' in-ground exposure is given. Four of the 5 test sites have a termite hazard in addition to the hazard from a range of decay fungi. Values for specimen life are given only where all replicates of a timber species have become unserviceable. Results give evidence leading to doubt about the accuracy of the tentative durability ratings previously ascribed to at least some of the species under test.
J D Thornton, G C Johnson, I W Saunders


Patterns of long-term performance - How well are they predicted from accelerated tests and should evaluations consider parameters other than averages?
1998 - IRG/WP 98-20130
This paper is a discussion of whether different service-life distribution patterns of products treated with unlike preservatives can be predicted, modeled, characterized, or even anticipated from accelerated laboratory tests. Graphic displays of data from Forest Products Laboratory field plots with preservative-treated and fire-retardant-treated stakes demonstrate the importance of local environment as a factor that affects field performance and exhibits differences in dose-response patterns among treatments. These distribution patterns are discussed with reference to early failures, first quartile and median failure times, and distribution about medians. Questions are then asked about the relevance of these parameters to practical applications, about the need to consider population characteristics other than average in evaluations on new preservatives, and about the capability of accelerated tests to estimate these parameters.
R C De Groot, J W Evans


Criteria for basidiomycetes testing and ways of defining natural durability classes
1998 - IRG/WP 98-20144
Within the framework of a European research project several laboratories have tested a series of 17 wood species covering the total range of natural durability. Basidiomycete tests are part of the total set up. Although generally based upon standard methods some minor differences in execution of the tests were evaluated for their impact on the results. This variation was superimposed with the fact that the tests were performed in different laboratories using wood from the same origin. Another important issue is the definition of natural durability classes for wood species starting from mass losses resulting from basidiomycete decay tests carried out under laboratory conditions. This paper summarises proposals for different ways to calculate or define the natural durability of wood and discusses some critical parameters in fungal testing, as well.
J Van Acker, M Stevens, J K Carey, R Sierra-Alvarez, H Militz, I Le Bayon, G Kleist, R-D Peek


Durable fibre for durable MDF – testing Tricoya®
2015 - IRG/WP 15-40704
The chemical modification of wood has been a commercial reality for a decade on release of technologies for the modification of solid wood including Accoya®. A challenge and an opportunity for the modification technologies which typically impart dimensional stability, water stability and enhanced biological durability was the adaptation of the technology to wood based panels. This paper presents a summary of the development of Tricoya®, its testing and performance and examples of applications.
E Suttie, J Alexander, M Maes


Attempt for developing a new method for above ground field testing of wood durability
2000 - IRG/WP 00-20199
Field testing remains the most appropriate way for evaluation of wood preservatives or natural durability of wood species. Above ground tests are designed to answer specific questions concerning the outdoor utilisation of wood. Such methods supply additional information and confirm or reject preliminary laboratory results. The European standard (ENV 12037, "lap-joint") for assessment of the durability of preservative treated wood in above ground testing has recently been proposed. It may also be used to assess the natural durability of wood. The objective of the present paper is to bear some discussion on alternative above ground test methods. The existing lap-joint field test corresponds to the real exploitation conditions of timber, but shows no decay after 2-3 years of exposure. This could be misleading when assessing the efficiency of preservatives. The method suggested acts more quickly compared to the lap-joint method with regard to mould, stain and, presumably, decay fungi. It is an accelerated above ground field test providing conditions favourable for fungal growth, but following close the fluctuations of climate. Results are shown where samples treated with preservatives for above ground use and untreated samples were exposed to the accelerated above ground test for several months. Fungal discoloration of the timber surface was classified by visual examination according to a seven-grade scale. The field test described here may be recommended for quickly testing of the natural durability of wood in above ground conditions as well as for approval of preservatives.
N Terziev, M-L Edlund


The use of modulus of rupture and modulus of elasticity in natural durability testing
1997 - IRG/WP 97-20117
Losses in weight, losses in bending strength and changes in elastic behaviour were assessed in a fungus cellar test with beech wood stakes (Fagus sylvatica). Results were gained after 8, 12, 16 and 20 weeks resp . The outcomes show, that the non-durable species beech is very rapidly attacked by fungi and loses up to 60% of its initial bending strength even within the first 8 weeks. Earlier research by Militz et al. (1996) showed that a durable species in the same period and under comparable conditions do not have any strength reduction. An assessment of weight loss lead to mass losses of ca. 20 - 30% within the same period. From the results it can be stated, that the use of MOR instead of or in combination with weight loss assessments have some advantages to the solely use of weight loss assessments. Furthermore, the outcomes show that as a non-destructive method, MOE assessments are a good tool in the prediction of fungal attack. For the inspection of field trials, the dynamic vibration method can offer some advantages, because no laboratory equipment is needed and the measurements only take some seconds. Further research is ongoing to gain more knowledge on the role of varying moisture contents of stakes in field trials on this type of MOE assessment.
L Machek, H Militz, W Gard


The natural durability of wood in different use classes
2003 - IRG/WP 03-10457
The natural durability of important European wood species has been tested on 3970 specimen in field trials. The wood was exposed at five test fields in Germany with different climates at each site in European hazard class 4 and 3 (with and without soil contact). Within EHC 3 it was distinguished between tree different expositions (end grain sheltered, unsheltered and with water trap). The test is now running for 3 years. The results have shown that the type of exposition (EHC 3 or EHC 4) has a strong influence on both: the decay activity and the durability determined as the quotient of decay of tested species and of decay of Scots pine sapwood. The test site had a strong effect on decay activity and time to failure, whereas the effect on durability was minor. Up to now it is not yet possible to calculate the final durability classification, but so far the field tests in soil confirmed the natural durability given in EN 350 (with the exceptions of Quercus robur and Robinia pseudoacacia, both were less durable than said in the standard). Whereas so far the above ground tests revealed a higher durability for all softwood species with coloured heartwood (heartwood of Larix, Pseudotsuga and Pinus) than classified in the standard EN 350. It is obvious that the current classification of natural durability is only valid for use in soil contact. Future amendments of the standard EN 350 seem to be reasonable. It is proposed to list durability class separately for in ground and for above ground use in the future.
U Augusta, A O Rapp


Assessment of wood decay in small-scale unsterile soil-bed tests
1997 - IRG/WP 97-20111
This study is concerned with the investigation of wood decay in small-scale unsterile soil-bed tests. Tests were performed with untreated heartwood samples from five hardwood species of different natural durability classes ranging from highly perishable to very resistant. Our results confirmed the critical role of soil moisture content on wood decay. The highest decay rates were observed at moisture levels close to the soil water holding capacity (WHC). With all the wood species tested, decay was retarded in soils with lower or higher moisture contents. Modification of the soil properties by addition of different amounts of an inert porous material did not affect the extent of wood decay provided that the moisture content of the modified soils was maintained, in each case, at their respective WHC. Test performed with mini-stakes (5 x 10 x 100 mm3) and smaller mini-blocks (5 x 10 x 20 mm3) showed similar levels of decay, irregardless of the test specimen size. In both cases, high mass and modulus of elasticity losses were observed in the highly perishable to moderately durable wood species after only 12-18 weeks of exposure. Based on the extent of wood decay, the small-scale soil-bed test was found to successfully discriminate between wood species in different natural durability classes.
L Machek, A M Derksen, R Sierra-Alvarez


Natural durability of 4 different Larix species tested in soil contact
2002 - IRG/WP 02-10434
Importers of Siberian Larch claimed to have a material which can replace pressure treated wood in soil contact. This gave reason to investigate the durability of 4 different Larix species (L. decidua, L. sibirica, L. decidua x sibirica, L. gmelini var ologenis) coming from 7 different origins in comparison with sapwood of Pinus sylvestris untreated as well as pressure impregnated with retentions of 2 and 9 kg CCA per m³. 10 mini stakes of each material in the size of 200 x 20 x 8 mm were installed in 1997 in the soil of the BFH test site (altitude = 24 m above see level, latitude = 53.5028 North, longitude = 10.1982 East). Within the first 2 years all except one untreated specimen of the Scots pine sapwood had failed. Within the first 3 years all except one of the Scots pine with a retention of 2 kg of CCA had failed. Within 5 years all specimen of Larix spp., independent from the species, had failed, whereas the pressure impregnated Scots pine with a retention of 9 kg CCA / m³ was either not or only slightly attacked. Mean life time and the average life time - which were about the same - served to classify the natural durability of the tested materials according to EN 350-1 (1994). All tested material was in the range of the value given in EN 350-2 (1994): "moderately to little durable" (European durability class 3-4). This was also valid for Siberian larch with narrow grow rings. From this results can be concluded that the performance of Larix heartwood in ground contact is far below that of wood properly treated with 9 kg CCA / m³. The field results are compared with earlier lab results using the same source of Larix material (IRG/WP 97-10228; IRG/WP 98-10287; IRG/WP 00-10350).
A O Rapp, H Viitanen, T Nilsson


The natural durability assessments of secondary timber species - field trials
1998 - IRG/WP 98-10297
Secondary or 'alternative' hardwood timber species can replace traditional hardwoods and contribute significantly to satisfying the overall demand for hardwoods in the UK timber market. A selection of these 'alternative' hardwoods is currently being tested at BRE-WTC for natural durability both in ground contact (to EN252) at two field sites, and out of ground contact (as L-joints to EN330) at one site. The objective is to provide an assessment of the suitability of each species for future commercial application. Moisture movement has been monitored in the L-joint tenons showing in less durable timbers, such as rubberwood (Hevea brasiliensis), rapid in-depth wetting during rain. Other monitored features of timber failure in out-of-ground exposure, including surface mould, cracking, discoloration and rot, indicate to date clear species-based differences. Comparison of the test timbers, based upon responsiveness to moisture and degree of timber failure, classify calophyllum (Calophyllum spp.), Ghanaian teak (Tectona grandis) and niové (Staudtia stipitata) as most durable and least reactive to moisture. The results to date of the ground contact trials, when compared with archived durability data show that the archive records of ground contact natural durability remain valid, although some modern plantation-grown timbers, such as teak (Tectona grandis), appear less durable than material from virgin forest. The likely value and commercial application of some of the secondary hardwood timbers examined is summarised.
E D Suttie, R J Orsler


The influence of the location of a wood defect on the modulus of elasticity determination in wood durability testing
2004 - IRG/WP 04-20287
This study investigates the influence of the location of a wood failure in stakes upon elastic changes observed in beech specimens with the resonance vibration technique. Natural failures were simulated by artificially created defects at different locations of the test stake. The results indicate that the location of an attack in a stake is important for the measurement outcome. When the attack is located at far ends of a stake, the detected faults are underestimated. Higher losses of modulus of elasticity were recorded with notches in comparison to bore hole defects. The non-destructive vibration approach (dynamic MOE) applied in durability testing offers advantages compared to conventional static techniques.
L Machek, H Militz


A comparison between different accelerated test methods for the determination of the natural durability of wood
1996 - IRG/WP 96-20099
According to the European standard EN 350-1 the natural durability of wood is defined as: "the inherent resistance of wood to attack by wood destroying organisms". This standard also describes how, for certain hazard classes, the durability is determined. The two methods described in this standard are the kolleflask method (EN 113) and the field-stake-test method (EN 252). The EN 113 test gives results within a short period of time by using isolated fungi cultures. A good prediction from the test results to the natural durability of timber in use is a problem. In contrary, the test results of EN 252 in outdoor field tests show the durability of timber species under certain soil and climate conditions, but the test takes a long period of time (years to decades) before an evaluation can be done. In different countries in Western-Europe a discussion is going on about the use of tropical hardwoods and timber from fast growing plantages. The impact of this is that there is a growing need for alternative timbers, which can substitute well known durable species. Quite often the durability of the alternative species is not well known. To give a reasonable prediction of the durability of wood species within a short period of time, a reproducible, reliable and fast test method for predicting durability is needed. Previous research on this subject (Polman et al. 1992) showed that with the aid of an accelerated stake-test, useful results can be achieved. The research described here was done to develop such a method. For this reason, results from an accelerated soil bed test were compared with EN 113 fungal tests and a modified field-test EN 252. For a further comparison, softrot tests following the standard ENV 807 were performed.
H Militz, S G L Michon, J E Polman, M Stevens


Evaluation of the european standard ENV 12038 for durability testing of plywood
2001 - IRG/WP 01-20237
The latest improved version of the standard ENV 12038 drafted as document N44 by CEN Technical Committee 38 (WG 7 - WG 23) is used to evaluate the effect of wood composition and structure on plywood durability. The method described is based on the agar-block test of the EN 113 standard used for the determination of the efficacy of wood preservatives and the assessment of the natural durability of timber. This test method differs from the soil-block test commonly used in North America and vermiculite test procedures used earlier for plywood testing. The ENV 12038 method is essentially developed to deviate minimal from the European basidiomycete tests currently established. Therefor it was important to evaluate whether or not vermiculite or soil as a test medium could be replaced by a malt- agar medium using an adequate preconditioning of panel specimens prior to fungal testing. Based on two consecutive experiments both test methodology and the assessment of plywood durability are investigated. Plywood is a material that allows a direct evaluation of test methods for assessing the durability of board materials in comparison with test methods used for solid wood. The presence of glue-lines and the layered structure based on solid wood veneers enables to investigate in detail the impact of wood composition as well as the type and amount of glue. Preconditioning plywood prior to testing according to ENV 12038 proved to be essential. However the impact of the glue is not entirely eliminated that way.
J Van Acker, M Stevens, E De Clercq


Laboratory testing of wood natural durability - In soil-bed assays
1998 - IRG/WP 98-20141
Laboratory methods for assessing wood decay resistance are being investigated in the framework of an ongoing European research project. This paper summarizes the main results obtained for soil-bed tests based on the European prestandard ENV 807-Test 2. The data suggest that this testing methodology is suitable for evaluating the natural durability of timber species in soil-contact under conditions which promote soft rot. Results after 16 weeks of exposure were found to enable the assessment of wood durability. Both, mass and strength (MOE) loss determination proved suitable for hardwood testing. In contrast, only the MOE losses recorded for softwood species were correlated with their expected decay resistance. The lack of correlation between mass loss and durability data is likely related to the very slow decay rates found for softwood timbers in the soil bed. Furthermore, artificial weathering prior to testing was shown to affect the susceptibility of some timber species to soft rot decay. This suggests that a weathering step may be required prior to biological testing. Wood leaching by the protocol described in EN 84 deserves attention as a possible alternative to the very expensive and time consuming artificial weathering pretreatment. In conclusion, laboratory soil testing using a modified ENV 807-Test 2 methodology can be recommended for assessing the durability of timbers to be used in ground contact. Such tests can provide useful information to complement the results from basidiomycete tests. The potentials of basidiomycete tests based on EN 113 to assess the natural durability of timbers were also investigated. The main findings will be presented at this conference by van Acker et al. (1998).
R Sierra-Alvarez, I Le Bayon, J K Carey, I Stephan, J Van Acker, M Grinda, G Kleist, H Militz, R-D Peek


Is laboratory testing of decay resistance questionable as a single criterion for natural durability?
1996 - IRG/WP 96-20096
In a laboratory test set up over 20 hardwood species were evaluated according to the European Standard EN 350-1 including Basidiomycete and soft rot testing. Half of the species used were of a known natural durability. The Basidiomycete testing was carried out using Coriolus versicolor, Gloeophyllum trabeum and Coniophora puteana in a malt agar test similar to EN 113. From this test it was not possible to rank the wood species according to known natural durability, only a distinct differentiation between species belonging to the group of durability classes 1 to 3 and the ones of durability classes 4 and 5 was noted. Since most wood species with little information on durability are so-called lesser known species belonging to the tropical hardwoods, it seems that only limited additional information is gained from brown rot tests supplementary to white rot tests. Both types of laboratory soft rot tests according to ENV 807 (vermiculite and soil) are able only to identify significantly the durability classes 1 to 4 from class 5, although somewhat better indications are obtained from the soil test. It is evident that other types of fungal attack like blue-stain in service, being an important parameter for window joinery, is not correlated at all with natural durability data obtained from soil testing. It is concluded from this research that durability testing would be better hazard class oriented in order to identify functionality of the end products derived.
J Van Acker, M Stevens, T Van Cauwenberghe, T Seynaeve


Laboratory tests on the natural durability of timber methods and problems
1984 - IRG/WP 2217
In literature a large variety of test methods is mentioned to examine the natural resistance of timber against fungal attack. This concerns the kind of sampling as well as the test procedure, the test fungi, the duration of test, and the classification of the resistance according to the test results. These variations, however, are of great influence on the test result. Long term exposure will lead to a further differentiation of timber species to be generally known as "resistant".
H Willeitner


A dynamic approach to assess the modulus of elasticity in wood decay testing
1998 - IRG/WP 98-20139
In this study, the changes in elastic behaviour and mass losses of different hardwood and softwood species exposed to decay in a laboratory soil tests were assessed. Wood decay was monitored using different assessment methods, namely: mass loss and changes in elastic behaviours (MOE) determination. Elastic changes were determined by static and dynamic methods, for the latter, acoustic technique was applied. The results obtained show a high correlation between dynamic and conventional static bending measurements of test specimens at different stages of wood decay. The non-destructive assessment of modulus of elasticity assessment proved to be a good tool in the prediction of early stages of wood decay.
L Machek, H Militz, R Sierra-Alvarez


A new concept for the evaluation of wood durability for out of ground contact using accelerated L-joint testing
1997 - IRG/WP 97-20123
Since the wood preservation sector is developing in favour of defining exactly the utilization of wood products and preservation techniques as a function of the envisaged hazard class, more in particular the hazard classes 3 and 4 (EN 350) there is obviously a need for a test method evaluating natural durability for out of ground contact applications. Based on the L-joint test as described in the European standard EN 330 a test method is under evaluation to determine the out of ground contact durability of various temperate and tropical wood species. Major parameters in the accelerated L-joint durability test are: the open joint structure, an exposure with 10° inclination facing sout west, tenon members in a 50/50 beech - Scots pine sapwood combination and a controlled drip irrigation system in the joint corner. This new concept is independent of specific coating systems and minimizes the variability in testing due to long dry periods under certain climatic conditions.
J Van Acker, M Stevens


European standardization for wood preservation. Progress report 91-92
1992 - IRG/WP 92-2398
Since the IRG 22 conference in Kyoto, CEN/TC 38 Plenary met twice in relation with several working group meetings. 5 upon 6 of the interpretative documents have been prepared by adhoc groups of the Standing Committee for Construction within the scope of the 89/106/EEC directive on Construction Products. The expected requirements attached to wood preservation are both requirements 1) and 3): 1) mechanical resistance and stability; 3) hygiene, health and the environment. A consequence should be a redrafting of the previous official mandate delivered on September 27, 1989: - direct mandate on wood (solid and reconstituted) as well as wood preservatives as construction products - horizontal joint-mandates on wooden-commodities in relation with the other TCs in charge of such commodities. Another consequence is a formal exploration by TC 38/WG 11 "Permanence of active ingredients in treated timber" through a first couple of standards entitled "methods for measuring losses of active ingredients and other preservative ingredients from treated timber - Part 1: Laboratory method for measuring losses by evaporation to air - Part 2: Laboratory method for measuring losses into fresh water or salt water". This works anticipates the mandate and means that TC 38 is currently making progress, towards air and water quality. Apart from building activities, TC 38 got also by the end of 1991 an order of standardization on Creosote, and Creosoted-timber following the 13th adaptation of 76/169/EEC Diretive Creosote specifications. This additional event results from the trend in Brussels to develop the so-called "new approach" where the EC authorities elaborates essential requirements with mandates to CEN explicit them in close cooperation with the industry.
R Hüe


The use of lap-joints in natural durability testing: moisture content development during 36 months outside exposure trials
2000 - IRG/WP 00-20217
Lap-joint trials (following European Standard ENV 12037) were set up with 11 different softwood and hardwood species. The main aim was to evaluate the suitability of this test standard (developed for testing wood preservative effectiveness) for natural durability testing. The moisture development has been followed during a 36 months period. In this paper, the outcomes of different moisture contents evaluations are presented. Completely painted samples without a lap-joint have the lowest moisture content with an increasing maximum in moisture content in the winter period over the years, however for most timber species (but pine sapwood) still staying around 20%. The painted lap-joint samples have the highest moisture content with long periods above 30%-50% for most species. The moisture content of the lap-joints is predominantly influenced by the wood species. By applying a coating to the lap-joints, all species stay wet for longer periods (more than a year). For lap-joint trials without any coating, most of the (hardwood) species stay relatively dry for longer periods, not allowing any fungal decay. In general it can be concluded, that a lap-joint approach can contribute to natural durability testing, however the course of decay under mid-European climate is very slow for an accelerated method.
H Militz, C J Bloom


The critical timing of inspections for field testing of natural durability
1994 - IRG/WP 94-20018
An overestimation of performance will almost always result if the condition of a specimen is considered to be attained at the precise time that an inspection is carried out. The time at which the condition is actually attained, referred to in this document as the "Condition time", is best considered to be halfway between two successive inspections. The requirement to obtain data that is relevant to the condition time may be overlooked by persons planning an inspection schedule, but the intervals for inspection are critical when expected class limits (such as time limits for performance of different classes of natural durability) have to be addressed. This paper discusses appropriate inspection procedures for both future CSIRO tests of natural durability and, more precisely, relevant to Standard pr. EN 350 Part 1. These proposed procedures are all based on the determination of median specimen life values rather than mean specimen life.
J D Thornton


Variation in field test performance of untreated and CCA-treated lesser-known Surinamese wood species
2000 - IRG/WP 00-20213
In Suriname three different field test sites have been used to verify the biological durability of CCA-treated wood and a range of wood species including lesser-known and lesser-used wood species. In total 37 tropical wood species were tested untreated and for 17 of the less durable species CCA-treatments were included as well. Although the three sites are located in the tropical region they differ with regard to soil and micro-climatic conditions. This is reflected by the results gathered from the durability tests. The observed variability shows that relevant conclusions on natural durability and efficacy of a preservative treatment can only be gained if different test sites are used.
J Van Acker, M Stevens, L Comvalius


Testing durability of treated wood according to EN 252. Interpretation of data from Nordic test fields
2006 - IRG/WP 06-20341
To evaluate the effectiveness of new wood preservatives intended for treated wood in ground use there is a European standard, EN 252. The test shall run for five years before any formal interpretation of the results can be made. Due to environmental concerns, the use of wood preservatives based on copper, chromium and arsenic (CCA) has been restricted in recent years. As a consequence of restrictions, several chromium and arsenic free preservatives based on fungicides regarded as more environmentally acceptable have been registered for use in the Nordic countries. Experience from our field tests shows that some preservatives perform quite well in field tests during the first five years but fail during the next five year period, while other perform quite good even during longer time in field. The aim with the study was to find early signs to predict preservatives service life by using other evaluation procedures than those described in EN 252. The aim has not been reached. To find the early signs to predict a short service life the field test according to EN 252 must be coordinated with other relevant methods to overlap weaknesses in EN 252. Some changes of the standard could give a better understanding of the performance: - Additional stakes must be treated to analyse the penetrating properties of the preservatives. - The test must be carried out in more than one field with different dominating wood destroying micro-organisms. The quality of the fields must be declared. Preferably the stakes shall be exposed to all kinds of wood destroying micro-organisms. - Test reports must include both index of decay with standard deviation and number of attacked stakes with different grading for the whole test period. - Test reports should also include decay type found in the stakes - Testing according to EN 252 must be combined with other relevant test methods.
M L Edlund, F G Evans, K Henriksen, T Nilsson


Testing biological durability of wood-plastic composites
2006 - IRG/WP 06-20347
Testing biological durability is inherently different for wood-plastic composites (WPC) compared to solid timber. However there is clearly a need for more information on the durability of WPC’s, on the effect of decay on the material properties of WPC’s and on methods for assessing decay of WPC’s. For the emerging European WPC market there has been some discussions on how to work on these topics. Laboratory testing is focussing on using the most appropriate test methods from the wood durability testing. Basidiomycete testing as was developed for wood based panels is proposed and soft rot testing can be done in accordance with laboratory methods for the evaluation of natural durability. There is however concern on the pre-leaching or pre-conditioning required to be in line with the slow water uptake of most modern wood-plastic composites. This is also of concern when dealing with field testing and probably will require out of ground contact testing with extra control of the moisture balance. It is also relevant that testing will become a requirement when dealing with the EU Directives on biocides (BPD) since many wood plastic composites contain fungicides and the one on construction (CPD) when load bearing applications are envisaged. Finally it is considered important to benchmark the WPC products concerning their biological durability with commonly used wood based products for different commodities allowing as such a better prediction of service life.
J Van Acker


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