Your search resulted in 44 documents. Displaying 25 entries per page.
Rates of emission from CCA-treated wood in the marine environment: measurement, modelling and requirements for further research
2001 - IRG/WP 01-50166-12
Accurate estimates of rates of emission of leachate from preservative treated wood are crucial for realistic predictions of the environmental impact of its use in maritime construction. Estimates are available for some commonly used preservatives, but these vary widely. Though variable, these measurements suggest that emission generally decreases exponentially with time. Part of the variation is due to differences in methodology employed. Physical and chemical characteristics of the seawater used (e.g. temperature, salinity, pH and oxygen content) affect emission rate. So too do the specifics of the treatment process especially the preservative formulation used, and pre- and post-treatment handling of the wood. The nature of the treated wood samples is also important, with misleadingly high estimates being obtained from samples with unrepresentatively high proportions of cross-cut surfaces. A suggested strategy for developing an informative and standardised methodology is discussed. To form useful models of impacts of leaching, emission rates need to be considered in conjunction with site-specific information regarding a) water exchange rates between the area where leaching occurs and the sea, and b) the extent of partitioning of leachate between the water column, biota and sediment. The risk of environmental impact may be reduced by modification to treatment procedures and by careful planning of installation.
S M Cragg, C J Brown, R A Albuquerque, R A Eaton
Wood decay in Danish buildings
1985 - IRG/WP 1261
At Technological Institute identification of fungi and advisory activity concerning repair of damages has taken place since 1935. Statistical analyses based on material from 1982 and 1983 are compared to earlier investigations worked out by L. Harmsen. The material shows that building traditions influence the diversity and frequency of fungal species. Many fungal damages in the last decade have showed that it is very important to use timber in a suitable manner not forgetting old building traditions. The conditions of fungal attack must be analysed and followed up by improvement of constructive and chemical wood protection.
A P Koch
Timber Preservation and Sustainable Construction in Australia
2005 - IRG/WP 05-50224-14
Sustainable development has been described as meeting the needs of the present without compromising the ability of future generations to meeting their own needs. (Bruntland 1987) To achieve the sustainable development goal therefore, the maximum performance has to be obtained from existing resources (timber) so that the remaining resource is protected from over-exploitation. Clearly, wood preservation has an important role to play in achieving the longest life from timber and timber products currently going in to service. Australia has a large number of naturally durable timbers and wood preservation systems have evolved to mimic and complement the natural durability of the heartwood of the material being treated. Whilst Australian wood preservative specifications have targeted the biological hazard and not the commodity, recent innovations with organic solvent preservatives have seen new products entering the market for very specific commodities. Consumer and specifier education remain a major issue for the wood preservation industry, even though specification and identification systems have been simplified as much as possible.
Termite barriers for new construction
2000 - IRG/WP 00-10341
Subterranean termite protection in Australia has traditionally relied upon the creation of a zone of poisoned soil under and around the structure to prevent termite attack from the ground. The transition away from persistent soil poisons which began with the withdrawal of cyclodienes in 1995 provided market opportunities for innovative barrier systems. The new barrier systems currently being used in Australia can be split into two groups: (i) non toxic physical barriers which exclude termites through the use of impenetrable materials and (ii), toxic chemical barriers which do not use the traditional hand-spray to soil application method.
D M Ewart
An investigation to assess the feasibility of developing an accelerated laboratory test to determine the abrasion resistance of lesser-used timber species for use in marine constructio
2005 - IRG/WP 05-20317
The paper describes the evaluation of a laboratory-accelerated test to compare the shingle abrasion resistance of current and potential timbers for use in marine construction. Useful results were achieved in 47.5 hours, but identified a number of issues to be resolved for the test to be refined and the subsequent results to be interpreted correctly.
G S Sawyer, J R Williams
A review of environmental emissions from building and construction materials in comparison with preserved wood
2005 - IRG/WP 05-50224-11
A review of the public domain literature concerning emissions to the environment from materials which are used in the construction of buildings (e.g. Concrete, Asphalt, Galvanised Steel), in comparison with preserved wood, and a review of the approaches taken by the construction sector in assessing the risk from environmental emissions, in comparison with the approaches taken by the wood preservation sector.
E F Baines
Study on the treatment of construction timbers by diffusion methods
1983 - IRG/WP 3252
Several species of timber that could be used for constructional purposes have to be pressure impregnated before such use. Pressure impregnation requires expensive equipment, and needs specialized trained operators, etc, which is not possible in most parts of India. Some timbers cannot be pressure impregnated, but can be treated by diffusion. Diffusion treatments could protect these timbers with simple inexpensive apparatus, using local resources and labour. It is our purpose, therefore, to locate such species which are commonly used in India for constructional purposes, and to preserve these by diffusion; to check if the results are satisfactory, and to find a preservative and simple procedure for the treatments of these timbers based on their treatability.
V R Sonti, B Chatterjee
Disposal of Pressure Treated Wood in Construction and Demolition Debris Landfill
2005 - IRG/WP 05-50235
Pressure treated wood is often disposed in landfills in the US, very frequently in construction and demolition (C&D) debris landfills. C&D debris disposal facilities in many states are not equipped with liner systems to protect underlying groundwater. In this paper, issues associated with the disposal of metal-containing treated wood in C&D debris landfills are discussed. C&D debris landfills can be biological active systems, dominated by the activity of sulfate reducing bacteria. The leachate is characterized by relatively low biodegradable organic compound concentrations, high salt concentrations, a neutral pH, and a moderately to strongly reducing environment. Simulated landfills containing CCA-treated wood often show relatively high concentrations of As and Cr, but only minimal concentrations of Cu. Cu-based preservatives such as alkaline copper quaternary (ACQ) also show minimal copper leaching, suggesting that disposal of Cu-based wood preservatives posees minimal impact to groundwater from Cu leaching.
T G Townsend, B Dubey, J Jambeck, H M Solo-Gabriele
Risk reduction from curative treatments, restoration and maintenance of building and individual housing - simple precautions that make the difference
2005 - IRG/WP 05-50224-15
This document explores the potentialities of risk reduction, from activities of remediation in construction, developped at small scale by professionals or individuals on targets like moulds, rots, termites and other wood destroying insects, with products distributed for professional or do-it-yourself purposes. At the first stage, an inventory of the type / interest of products / processes is carried out, with the identification of the sequences, including the fate of wastes and the resulting exposure for the compartments of interest. For health aspects, a crude practical evaluation of the exposure of direct receptors, operators, and indirect ones, inhabitants and the public in the vicinity, to the pathologies and their remediation, seems possible. This exercise aims to provide the users of products with the minimum set of tools and criteria of direct exposure assessment, prior to their use, based on available documentation, regulation and warnings. The best case occurs with the access to material safety data sheets and the corresponding labelling. Per default, they take available products from the shelf (approved for marketing or restricted use, doses, conditions of application), with the support of suppliers and local requirements. Regular training is one way of progress, the obligation of result with procedures adapted to the site of the building and its own exposure, another route of improvement. As works in this field are often non typical, there is still room for the optimisation of individual options, based on experience, to locate the necessary dose and performance at the right place. Description and examples are provided.
Leaching of Arsenic from Mulch Made from Recycled Construction and Demolition Wood
2005 - IRG/WP 05-50232
Mulch made from recycled construction and demolition (C&D) wood has been reported to contain chromated copper arsenate (CCA)-treated wood and potentially release arsenic in the leachate by rainfall. Such recycled wood mulch is commonly masked with iron-oxide colorant, which is known to combine with arsenic. The objective of this study was to evaluate the levels of arsenic leaching from C&D recycled wood mulch and potential effects of the colorant on leaching rates. Mulch samples observed were paired (dyed and non-dyed) in three groups [untreated wood, 5 % treated wood, and 100 % treated wood]. The leachates were collected for one year and analyzed for arsenic. Arsenic in the leachate from untreated wood mulch was consistently at low levels (< 3 ~ 13 ug/L). The average concentrations from 5 % treated wood mulch were 341 (non-colored) and 258 μg/L (colored). The average concentrations from 100 % treated wood mulch were 4,490 (non-colored) and 3490 μg/L (colored). For the entire one year monitoring period, the colorant reduced the arsenic concentration by 24 and 29 % for the non-colored 5 % treated wood mulch and 100 % treated wood mulch, respectively. The study showed that recycled C&D wood mulch, which contains small percentages of CCA-treated wood, release significantly large levels of arsenic by rainfall and iron oxide colorant reduces the arsenic leaching rate for a short period.
T Shibata, H M Solo-Gabriele, T G Townsend, B Dubey
The possible role of mobile CCA components in preventing spore germination in checked surfaces, in treated wood exposed above ground
2001 - IRG/WP 01-30263
Untreated check surfaces are often exposed in CCA-treated lumber of refractory species used above ground since, during weathering, some checks develop beyond the preservative penetrated zone. However, decay is seldom observed in these checks even after many years of exposure. It is hypothesized that minor amounts of mobile CCA preservative components redistribute during weathering into checks, and that this 'surface treatment' prevents fungal spores washed into checks from germinating and causing decay. A substantial amount of copper was found on the exposed check and end-cut surface in exposed wood through the current research, and whether spores are prevented from germinating by this amount of chemical is being studied.
S Choi, J N R Ruddick, P I Morris
Construction of dhows in Kuwait
1981 - IRG/WP 465
To most people Kuwait means oil and the opulence associated with it, but to the seafarer, Kuwait means Dhows. There are as early references to the Kuwaiti Dhows as the 17th century. The Danish explorer Nebuhr in 1756 described Kuwait as having a work power of 10,000 people and 800 wooden boats involved in fishing, pearl diving, and trade. Dhows might well have been the original carriers of "The Perfumes of Arabia" referred to by Shakespeare in "Macbeth". At the coastal village of Doha, Kuwaiti shipwrights continue to build vessels that bear much resemblance to the ancient dhows. The aim of this paper is to show the construction of a traditional dhow with particular emphasis on the methods commonly used to preserve and prolong seaworthiness of these magnificent wooden ships.
A S Zainal, M A Ghannoum
New approaches to practical evaluation method of bio-degradation of wooden construction - Non-destructive detection of defects using radar technique
2000 - IRG/WP 00-20214
There have been a number of researches and developments on the techniques and apparatus for the nondestructive evaluation of the biological deterioration in wood and wooden constructions, such as decay or insect attack in house, public buildings or in historically important architectures. As for the detection of the decay in wood, techniques using sound in audible or in ultrasonic frequency ranges, stress waves, heat wave and X- ray have been investigated, where the changes in the physical properties expressed in the wave form were related to decay. The change in the velocity, the attenuation or the frequency spectrum of these physical energy waves can be associated with the decrease of the specific gravity or the structural change due to decay. Some mechanical properties such as the boring resistance and the elastic properties of wood surface could be an indicator of decay. The dielectric property of wood and its relation to decay is also useful. Miller et al. (1989) applied a radar technique to diagnosing of standing trees. However the techniques previously developed are not always feasible. One of the possible reasons is that these physical or mechanical properties change not only on decay but also on other factors, such as the water content or the grain direction in wood. In addition, sometimes the techniques are less practical, strictly not non- destructive or too expensive. In practical maintenance operation of wooden constructions, visual inspection together with sampling method plays an important roll, however a specialized training is needed for the operator to get the skill of the diagnosing. In this study, to establish a practical evaluation method of bio- degradation in wooden construction, scanning using a newly developed portable radar apparatus was investigated. By comparing the results with other methods, a more practical method to evaluate the bio-degradation in wood was proposed.
Y Fujii, Y Komatsu, Y Yanase, S Okumura, Y Imamura, M Tarumi, H Takiuchi, A Inai
Laboratory evaluation of termite resistance of five lesser-known Malaysian hardwoods used for roof and ceiling construction
2001 - IRG/WP 01-10398
The general laboratory procedure of AWPA E1-97 was used to evaluate the termite resistance of 5 lesser- known species (LKT) of Malaysian hardwoods: Kekatong (Cynometra sp.), Kelat (Eugenia spp.), Mempening (Lithocarpus spp.), Perah (Elateriospermum tapos) and Pauh Kijang (Irvingia malayana) against the subterranean termite Coptotermes curvignathus over 28 days. Kempas (Koompassia malaccensis) and Rubberwood (Hevea brasiliensis) were included for comparison with these LKT. Employing the AWPA five-point visual rating scale of termite resistance of wood material, Rubberwood and to an extent Mempening, were the least resistant (rating 4-7), Kekatong was virtually immune (rating 9) to the Coptotermes species, while Kempas, Kelat, Pauh Kijang and Perah sustained between light-to- moderate attack (rating 7-9). There was a tendency for higher final wood moisture content, higher mass loss or reduced termite mortality to correspond with the lower visual ratings (low termite resistance) generally. In-ground natural durability test results did not correlate with mass loss or visual rating data from the laboratory test.
A A H Wong, Kee Suan Cheok, J K Grace
Prevention of Termite Tubing Over Non-Wood Construction Materials Using Glycol Borate
2004 - IRG/WP 04-30358
Glycol borates have been demonstrated to prevent termite tubing and attack of wood materials and are extensively used as termite preventative applications in new construction in the USA. This study evaluated the ability of such systems to prevent Formosan subterranean termite tubing over non-wood materials. Concrete was selected as a common inert construction material and tests were carried out following topical treatment of the concrete with a commercially available glycol borate. It was found that a glycol borate treatment on concrete restricted the ability of termites to construct tubes. Exploratory tubes were less than 20 cm and the treatment caused near complete termite mortality. The results suggest that glycol borates offer a novel approach to protect cellulosic materials within structures not built from wood.
W R Smith, J D Lloyd
Valid scientific names of wood-decaying fungi in construction timber and their vernacular names in England, Germany, France, Sweden, Norway and Denmark
1992 - IRG/WP 92-1546
The valid scientific names of 100 species of wood decaying fungi in construction timber are listed, the citation of authors' names is standardized, and an index of the most commonly used synonyms is compiled. For each species vernacular names used in England, Germany, France, Sweden, Norway and Denmark are listed. The list of names is an attempt to update the current use of the most important species names used by specialists dealing with decay or discolouration of timber caused by fungi.
F Rune, A P Koch
Rubber wood for fishing canoe construction
2005 - IRG/WP 05-40319
The rubber tree (Hevea brasiliensis) is cultivated for its latex and the wood comes as a by-product from the rubber plantations. The highly perishable nature makes it unsuitable for boat building. The Central Institute of Fisheries Technology, Cochin conducted laboratory and field studies with chemical preservative treated rubber wood and found that the durability of the wood increased considerably. The preservatives used were Copper-chrome-Arsenic (CCA) and creosote. Three canoes were made of treated rubber wood and are being operated successfully for the past 30 months in the backwaters as well as in the sea by gillnet fishermen. As a logical sequel to this, canoes were constructed out of rubber wood treated with CCA alone and sheathed with fiberglass making them more durable. Three such canoes were made and are given for experimental fishing. Performance monitoring shows that these canoes are free from biodeterioration and physical damage.
L Edwin, S N Thomas, B Meenakumari
Variable chlordane residues in soil surrounding houses in Louisiana
1989 - IRG/WP 1404
Eight soil samples from each of 30 houses in greater New Orleans, Louisiana were collected in October, 1986 and analyzed for chlordane residues (ppm). All houses had reportedly been treated in the late 1960's or early 1970's. Chlordane occurred in all samples, and the overall mean (+ SEM) was 870.6 + 96.5 ppm. Residue levels were unaffected by construction type (slab, crawl, crawl/slab) or depth of sampling (0-5 cm or 6-10 cm). Considerable within-house variability of residues occurred, but crawl space structures were less variable than were slab structures. Low residues at 17 sampling sites were potentially inadequate to deter the introduced Formosan subterranean termite, Coptotermes formosanus Shiraki.
J P La Fage, K S Delaplane
Wood durability in the light of recent trends and research on the durability of building materials and components
2000 - IRG/WP 00-20195
Building-related research of today demonstrates a clear shift in focus from the design and production phases to usage and to the entire life time. A consequence is that the performance criteria of materials, components and of the entire building must be regarded over the life time rather than at the time of production or delivery. As one example can be mentioned the Building Construction Directive of the European Union were a number of essential requirements on buildings are stated. These requirements relate i. a. to safety and environment issues and are to be regarded as highly non-controversial. However, it is clearly stated in the Directive that these requirements must be fulfilled during the entire lifetime of the building. This means that the performance-over-time of each single material must be known and that a careful life time planning of the building must be introduced in the design and construction phase of the building project. To make this possible a lot of research is necessary and the research activity in this field is high. State of the art is presented every second year at the International Conferences on the Durability of Building Materials and Components, latest arranged in Vancouver in May 1999. In this paper the wood based and in special the chemically treated materials are discussed from the point of view of modern durability research approaches. The interaction between durability and environmental impact in a live cycle perspective is mentioned. A conclusion is that the research within IRG should be focused more on different building applications than has been the case so far. Examples of possible and necessary research projects are given.
Specifying preservative-treated resistant timber: Conforming to European Standards
2001 - IRG/WP 01-20235
The most common construction timbers used in the UK are of low natural durability and, generally, resistant to preservative treatment. These include species of spruce, hemlock and fir. However, their characteristically limited and non-uniform uptake of preservatives may still confer sufficient protection to give satisfactory durability performance in terms of biological resistance. This paper describes the results of a study investigating the protective efficacy of treatments defined according to the approach in European Standard EN 351-1 when penetration and retention values are used in timbers showing non- uniform treatment characteristics. The data show that variation between batches of samples is high for preservative uptake, retention and penetration. The biological data have given indications that this leads to differences in performance effectiveness. However, the bioassay method developed does not in its present form, sufficiently discriminate between treatment/species combinations.
E D Suttie, A F Bravery, T B Dearling
Compatibility of deltamethrin with wood-finishing and construction materials
1993 - IRG/WP 93-30010
Under normal use conditions, treated wood comes to close contact with the structural components of a buiLding, and/or receives finishing, forming a new interface, which can affect the performance of a new product such as deltamethrin. To study this possibility, block-tests of Parana-Pine (Araucaria angustifolia), measuring 12 x 24 x 0.5 cm³ (with the largest dimension parallel to the wood-grain), received brushing treatment with deltamethrin and kerosene in two different concentrations: 0.02% (w/w) and 0.04% (w/w). After 20 days under laboratory conditions, the block-tests received a superficial finishing with poliurethan varnish, enamel paint, oil paint (alkidic) and latex paint and were fastened in close contact, through rubber band, with bricks, building cement, concrete blocks and plaster. A set of pieces made up of these construction materials was treated with deltamethrin in the same concentration as mentioned above, forming a reference series. The test against dry-wood termites (Cryptotermes brevis) was carried out 21 months after the treatment. The deltamethrin proved to be very effective in wood protection, independently of the finish used and the type of construction material in contact with the wood.
E S Lepage
How to win friends and influence the market — Service Life Prediction and performance-based durability assessments of wood products in construction
2006 - IRG/WP 06-20348
Due to direct and implied demands from the market and from e.g. the EU Construction Products Directive, the need to supply service life estimates for building products is growing. For several years, a development of Service Life Prediction (SLP) methodologies has been going on, but the awareness of this development has hitherto reached only a very limited extent in the wood sector. For materials whose degradation in service is governed by not only physical factors but also, and in many cases to a dominating degree, by biological mechanisms, acurate service life estimates are particularly difficult. Still, in order to defend and expand the market for wood products in construction in the long run, it is of great importance that durability assessments are transformed and expressed in ways that are truly useful for specifyers and users. More clearly stated: The needs and the interests of the user should be in focus and should be the actual starting point for development of both products and durability assessment methods. An initiative to bring this discussion to the CEN Committee TC 38 “Durability of wood and wood-based products” has led to the formation of a Task Group, which will further look into the possibilities to incorporate SLP methods in European durability standards. This development has been carried into effect by the establishment in 2004 of a Task Force within the COST Action E 37 “Sustainability through new technologies for enhanced wood durability”. The Task Force has made preliminary work, making inventories of methods for testing and assessment, analysing the purposefulness of these methods, and giving some outlines for a future performance-based system of classification of wood products. The Task Force will give a final report of its work later this year.
A Prediction of Arsenic Groundwater Concentrations Influenced by Construction and Demolition Debris Landfills in Florida Containing CCA-Treated Wood
2006 - IRG/WP 06-50242
Groundwater fate and transport models can provide an indication of the potential impacts of arsenic from the infiltration of leachate from unlined C&D debris landfills containing CCA-treated wood. A solute transport model, Migration of Organic/Inorganic Chemicals (MYGRT), was chosen to predict groundwater contaminant concentrations at specified locations from a hypothetical source (C&D landfill) that contains CCA-treated wood. MYGRT simulates a single contaminant, generated from a surface source, migrating downward through the unsaturated soil layer, mixing with the underlying groundwater, and then migrating horizontally downgradient through the aquifer. The software incorporates the processes of advection, dispersion and retardation. Because of the slow and complex transport mechanisms involved, groundwater impacts may not be observed for many years. A small fraction of the arsenic from the CCA-treated wood disposed in C&D debris landfills was simulated as leached (17.1%). Although hundreds of years later, exceedances of current and potential groundwater cleanup target levels were predicted.
J Jambeck, T Townsend, H Solo-Gabriele
A roadmap for performance-based specification of wooden components based on service life prediction
2007 - IRG/WP 07-20351
The need for an unified and harmonised system for performance classification and specification of wood and wood-based products in Europe emanates from requirements of users and the European Construction Products Directive, CPD. A road to a feasible specification system is outlined. Exposure-related performance prediction was worked out as a key task on the way to product specification. Therefore suitable tools, field test methods as well as short-term/laboratory test methods, are sought to allow the determination of reference service lives for different exposure categories. On one hand, performance factors, which derive from service lives in field tests, allow the specification of wood products. On the other hand, the calculation of inter-site factors may allow the modelling of service lives and the drawing of hazard mappings.
C Brischke, A O Rapp
Construction of an ITS sequence database for the identification and classification of wood rot fungi
2007 - IRG/WP 07-10626
Developing a database that contains information about wood rot fungi is important in improving technologies about wood preservation as well as advances in understanding wood decay. On the other hand, with rapid spread of the Internet, establishment of a system for the swift precise access to information are required for the computerization of the research information. In the present study, genetic information of the wood rot fungi was analyzed for the construction of the database. The indoor fungi were selected from the fungal collection which is stored in the Deterioration Organisms Laboratory (DOL), The Research Institute for Sustainable Humanosphere (RISH), Kyoto University. Genome DNA was extracted from each isolate, and then the internal transcribed spacer (ITS) region was amplified by PCR using universal primer pair. The amplified DNA fragment was sequenced and was checked on the existing database such as GenBank in order to identify fungal species.
S Horisawa, Y Honda, S Itakura, S Doi