Your search resulted in 23 documents.
Conforming to european standards for preservative-treated timber: Specifying with confidence
2000 - IRG/WP 00-20194
A four-year collaborative study between four industrial partners and BRE has assessed timber treated by current UK industrial practices in the light of current European Standards. Data were collected for CCA and creosote treated timber components, and compared with the requirements laid out in EN351-1 and -2. A number of difficulties were encountered that have been described in previous IRG papers...
E D Suttie, R J Orsler
Assessment of losses of wood preservatives from treated wood by leaching into the environment
1993 - IRG/WP 93-50001-13
Wood preservative chemicals may be lost from treated timber by leaching into water or soil. The degree to which this might occur and its effect on the environment is difficult to assess quantitatively due to the absence of appropriate test methods. This paper describes work to assess test methodology capable of allowing the rates of loss of wood preservative from treated timber to be quantified. T...
R J Orsler, G E Holland
The rate of redistribution and loss of leachable preservatives under service conditions
1993 - IRG/WP 93-30026
This paper describes experiments carried out to determine patterns of preservative redistribution and any associated losses which occur when wood containing unfixed water-soluble wood preservatives is exposed to service conditions where leaching is possible. Scots pine sapwood treated with disodium octaborate was used as a model system. Results are recorded and discussed for trials representing pa...
R J Orsler, G E Holland
A comparison of the effectiveness of a vacuum oven and a wind tunnel in the accelerated ageing of treated wood by evaporation
1989 - IRG/WP 2334
R J Orsler, G E Holland
The biological natural durability of timber in ground contact
1994 - IRG/WP 94-20051
The BRE ground contact field trials for the determination of the biological natural durability of different timber species have recently been reviewed. The data obtained from these trials have been used to appraise the different ways in which natural durability may be expressed. It is concluded that the use of the mean as a method of assigning the timber to one of five durability classes may be ac...
G A Smith, R J Orsler
The permanence of permethrin in wood preservation
1984 - IRG/WP 3288
The permanence of the synthetic pyrethroid permethrin in treated wood has been assessed for double vacuum and immersion treated Scots pine sapwood and whitewood using a 0.5% m/m solution of the insecticide in a hydrocarbon solvent. It is concluded that for all but the outermost 0.5 mm of the treated battens the distribution of the permethrin is relatively permanent. The outermost 0.5 mm appears vu...
R J Orsler, M W S Stone
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 envi...
R J Orsler
The influence of the natural extractives of opepe (Nauclea diderrichii) and African padauk (Pterocarpus soyauxii) timbers on their durability
1996 - IRG/WP 96-30098
Many timbers contain chemical extractives that undoubtedly play a key role in the timber's natural durability. Opepe (Nauclea diderrichii) and padauk (Pterocarpus sp.) are both very durable timbers (class 1), yet they are described as being moderately permeable. This suggests the presence of biocidal chemicals within these timbers, rather than simple blocking agents. Initial trials on the...
E D Suttie, R J Orsler
A preliminary assessment of the penetration into wood achieved by bodied mayonnaise emulsion wood preservatives
1992 - IRG/WP 92-3725
Five different commercial formulations of bodied mayonnaise emulsions were applied to samples of Scots pine (Pinus sylvestris) sapwood as recommended by the manufacturers. Penetration and loading characteristics were determined by measuring the distribution profiles of the active ingredients after various intervals of time. The changes in the general appearance of the emulsions on the surface of t...
G E Holland, R J Orsler
BRE Experience in monitoring decay in out-of-ground exposure trials
1995 - IRG/WP 95-20077
The outdoor field trial has always been regarded as the ultimate test of performance for assessing the effectiveness of a wood preservative. For this reason, the Building Research Establishment (BRE) has invested much effort in such trials over many years. Emphasis in early trials was on ground contact tests which were the basis both for assessing the likely performance of a preservative in protec...
J K Carey, R J Orsler
Occupant re-entry times following insecticidal remedial treatments of timber in dwellings
1995 - IRG/WP 95-50055
This work was carried out principally to obtain quantitative data on the aerial concentrations of permethrin and white spirit likely to arise following the remedial treatment of timber in buildings, using insecticidal formulations. Such data are needed to allow assessments to be made of the length of time buildings should remain unoccupied following such treatments prior to re-occupation, and the ...
R J Orsler, G E Holland, G M F Van Eetvelde
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 c...
E D Suttie, R J Orsler
The treatment of Douglas fir fence posts: specification and compliance using new European standards
1999 - IRG/WP 99-20178
New European standards for the preservative pre-treatment of timber require the results of the treatment process to be specified and subsequently verified by examination of the treated timber for penetration and retention of the preservative. For penetration, the standards are restrictive in that there are only a limited number of options available to the specifier. Thus for ground contact service...
R J Orsler, H Derbyshire
Preliminary studies of the performance of iron chelators as inhibitors of brown rot (Coniophora puteana) attack
1996 - IRG/WP 96-10185
This paper describes experiments to examine the proposal that the presence of iron is essential for brown rot fungi to utilize hydroxyl radicals remote from the hyphae as a means of converting the wood into a food source. reliminary test results are presented from trials using three different iron chelators impregnated into Scots pine (Pinus sylvestris) sapwood blocks. Their relative effects on th...
E D Suttie, R J Orsler, P M Wood
Assessing the importance of degradation mechanisms on the loss of effectiveness of wood preservatives
2000 - IRG/WP 00-20193
Accelerated ageing systems developed for application to samples in the laboratory prior to biological tests, should reflect those natural deterioration processes that are likely to occur in the hazard classes defined in EN 335-1. Losses through evaporation or the effects of leaching have been recognised, however their importance, relative to other mechanisms has not been quantified. Degradation me...
E D Suttie, R J Orsler, T Dearling
Experiments in accelerated ageing
1984 - IRG/WP 2223
Experiments using a vacuum oven to accelerate the evaporative loss of g-HCH from treated wood blocks have indicated that the method described in this paper has the potential to reproduce in a relatively short time the distributions and loadings of the insecticide that are found during natural ageing. By contrast, the wind tunnel removed the volatile material in a way not found in natural ageing an...
R J Orsler, M W S Stone
Experiments on the degradation of tributyltin oxide: A progress report
1984 - IRG/WP 3287
A variety of experiments designed to assess the chemical and physical factors affecting the degradation of tributyltin oxide in treated timber are described. Simple procedures in which temperature and oxygen availability were increased in the presence of wood and water suggest that the wood itself was of prime importance. Attempts to decrease degradation with antioxidants were unsuccessful but led...
R J Orsler, G E Holland
Assessing the bioresistance conferred to solid wood by chemical modification
1997 - IRG/WP 97-40099
The chemical modification of wood using straight chain alkyl anhydrides can considerably enhance its durability. This paper presents an assessment of the effectiveness of these modifiers in improving the biological resistance of a susceptible softwood when exposed to four different basidiomycete fungi, soft rots and the larvae of the house longhorn beetle (Hylotrupes bajulus). It was clear that so...
E D Suttie, C A S Hill, D Jones, R J Orsler
Assessing health risks to occupants following remedial insecticidal treatment of timber in dwellings
1998 - IRG/WP 98-50101-27
Experiments have been carried out to assess (i) the aerial concentrations of volatile wood preservative constituents, and (ii) the potential for contamination from treated surfaces, following in situ insecticidal treatment of timbers in dwellings. Using white spirit as a model for volatile constituents in the treatment of free-standing, wood-lined chambers indicated that temperature and air exchan...
R J Orsler, E D Suttie, V Rijckaert
Methods for the assessment of wood preservative movement in soil
1995 - IRG/WP 95-50040-08
This paper presents preliminary results from a series of experiments constructed to provide laboratory data for the evaluation of the leaching of wood preservatives into and through soil. The experiments included: i) measurement of the adsorption of preservatives by soil; ii) determination of the concentration gradient of preservatives in soil following percolation of preservative solution through...
G E Holland, R J Orsler
A review of the implementation of results-based standards for preservative treated timber
1999 - IRG/WP 99-20156
European standards for the specification of preservative treated timber are written in terms of the results achieved in the commodity by the treatment process. This is described in terms of penetration and retention of preservative. Results from a study on the commercial application of this approach in the UK show the difficulties associated with applying the new European standards; particularly w...
E D Suttie, A S Hughes, R J Orsler
Effect of leaching temperature and water acidity on the loss of metal elements from CCA treated timber in aquatic applications. Part 1: Laboratory scale investigation
1995 - IRG/WP 95-50046
In order to investigate the applicability of current prestandard leaching test methods, a series of experiments has been performed on CCA impregnated wood dealing with the influence of pH, temperature and agitation of the surrounding water. The leaching method used in this first part of the investigation is the European prestandard drafted by CEN/TC38/WG11, a short term dynamic leaching test under...
G M F Van Eetvelde, R J Orsler, G E Holland, M Stevens
Conforming to European standards on preservative treatment
1998 - IRG/WP 98-20150
New European standards require that specifications for the preservative treatment of timber are written in terms of the penetration and retention of preservative within the treated commodity that result from the treatment process. In order to check compliance with this type of specification, suitable methods of quantitative analysis must be available. This paper presents the results of a study by ...
E D Suttie, R J Orsler