Your search resulted in 343 documents. Displaying 25 entries per page.
Co-operative research project on L-joint testing. Sampling after 4 years exposure
1987 - IRG/WP 2274
In September 1983, Document No: IRG/WP/2208 was distributed giving guidance on sampling after 8 months exposure and including tables on which to record the test results. Similarly in September 1984, Document No: IRG/WP/2233 was distributed concerning sampling after 18 months exposure. No major problems have been notified to Princes Risborough Laboratory concerning the sampling method. It is theref...
J K Carey, A F Bravery
Treatment groups and remedies for CCA treated hardwood and softwood poles
1999 - IRG/WP 99-40142
Different hardwood and softwood species from Bangladesh and Bhutan was investigated regarding density, green fiber stress, natural durability of heartwood and CCA treated sapwood, CCA treatability grades, sapwood thickness, and kiln-drying properties for long term use as electric poles. These properties along with the past service records for nineteen years, separated ten heardwood and five softwo...
A K Lahiry
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 ch...
J N R Ruddick, P I Morris
A technique for determining the efficacy of water diffusible preservative plugs for implanting in joinery in service
1987 - IRG/WP 2291
A technique is described for determining the efficacy of soluble, diffusible preservative plugs for eradicating decay in joinery. It uses blocks of Scots pine sapwood or heartwood adjusted to known moisture contents prior to the establishment of the test fungus Coniophora puteana, from a single longitudinal dowel and the subsequent introduction of the preservative plugs. Prevention of decay, eradi...
J K Carey, A F Bravery
Application of oscillating pressure to improve treatability of refractory species
1987 - IRG/WP 3449
Under practical conditions a minimum moisture content of 80% demande by the German quality standard RAL-RG 411 can not be guaranteed throughout the year. Storage of logs with bark prolonges the drying process; a storage without bark must be avoided. A sufficient penetration according the standard can be achieved at least with a moisture content of 60%, optimal conditions may prevail between 100% a...
R-D Peek
The effect of moisture content on the electrical resistance of timber as detected by a pulsed current reistance meter (Shigometer)
1984 - IRG/WP 2212
The literature concerning the use of the Shigometer® for detecting decay in standing trees and wood poles is reviewed and the differences of opinion over the effect of timber moisture content on electrical resistance are highlighted. A simple experiment designed to test this effect is described and the implications of the results for testing poles in service are discussed. There was a large diffe...
P I Morris, D J Dickinson
Moisture content of logs under sprinklers
2000 - IRG/WP 00-40157
Logs are kept under sprinklers during storage for avoiding the development of sapstain fungi. According to literature, sapstain fungi do not develop if the moisture content is above 120%. It is supposed that, the water sprinklers maintain the log's moisture content above this value, but, very often, sapstain is found on sawn lumber cut from these logs. Logs are harvested and transported t...
M C Rose, A M Briones, M Fernández
Moisture content and other tested values in. Double layer tests of different size in Lithuania and Germany
2004 - IRG/WP 04-20299
The paper presents measurement results of moisture content and the analysis of durability trial of double layer wood in variants of varying size, conducted in Girionys, Kaunas distr., Lithuania and in Hamburg, Germany. In this trial 3 sample sets of varying size, containing 25, 50 and 100 specimens, are used. The aim of this trial is to ascertain an optimal number of test specimens. The dynamics o...
J Saladis, A O Rapp
Whitewood - An external joinery timber?
1975 - IRG/WP 253
The timber used traditionally for softwood joinery in the UK is redwood (Pinus sylvestris). In the past its ready availability in the desired sizes and quality and its durability in service encouraged little competition. However, the past decade has seen some erosion of this position, particularly through the increased proportion of sapwood in redwood supplies. Since the sapwood is less durable th...
J W W Morgan
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 content...
H Militz, C J Bloom
Why don't more people work with Serpula lacrymans nowadays? A discussion of some of the different approaches to experimenting with this unique fungus
1989 - IRG/WP 1383
Remarkably few laboratories are currently investigating this well-known fungus. Not only has it failed to gain acceptance as a standard test organism (for wood preservative evaluation) in many countries, but is also sometimes excluded from pure research studies when it ought to be an obvious first choice as a representative basidiomycete. This paper discusses some different approaches that have be...
J D Thornton
Suitability of different termite species for laboratory testing
1982 - IRG/WP 1159
Different termite species were tested in the laboratory to evaluate the effectiveness of insecticides and wood preservatives in wood against termite attack. Determined were the optimum group size and composition, the matrix (vermiculite) volume and its moisture content. Choice feeding tests with fully impregnated wood blocks which are carried out according to a modified EN 117 procedure for Reticu...
U Kny, H Kühne
Penetration of oil-borne preservatives in American elm
1975 - IRG/WP 355
Pressure treatment of elm posts and cants by Rueping schedules resulted in erratic penetration. Instead of the expected gradual decrease in retention from surface inward in posts, inner zones frequently contained more preservative than the surface quarter inch. Heartwood was found penetrated when sapwood was not. There were numerous skips in treated zones. The prevalence and possible causes were i...
E A Behr
Protection of pine sawtimber and sawn timber against blue stain in Poland
1983 - IRG/WP 3193
The purpose of this paper is the synthesis of more important results of basic and applied research that have been grouped in the following problems: 1.: Fungi causing blue stain in the pine wood, occurring in Poland. 2.: Moisture content changes of pine sawtimber and sawn timber as the factor of blue stain producing fungi development. 3.: Effect of sapwood moisture content on the degree of wood st...
E Tarocinski, M H Zielinski
Factors affecting the resistance of fibre building boards to fungal attack
1975 - IRG/WP 252
Fungal decay is initiated at lower moisture contents in standard and tempered hardboards (18%) than in pine sapwood (26%). In contrast, in a saturated atmosphere, the equilibrium moisture contents of standard hardboard (14%) and of tempered hardboard (12.5%) are much lower than the moisture content permitting decay initiation whilst the equilibrium moisture content of pine sapwood (25.1%) approach...
C Grant, J G Savory
Effects of the delay in the beginning of treatment on absorption and distribution of water-soluble salts in posts treated by sap-replacement method
1992 - IRG/WP 92-3719
One of the most important matters in green wood treatments, such as sap-replacement method, is knowing the longest time available for beginning treatment without losing efficacy. In this paper, the influence of this factor on absorptions and distribution of the preservative into the wood is analized. Tree start-up times were first chosen: 3-6 hours, 48 h and 120 h after being cut down. The treatme...
M V Baonza Merino
Moisture correction for ultrasonic MOE measurements above fibre saturation point in Scots pine sapwood
2006 - IRG/WP 06-20333
There is a high correlation between methods for dynamic modulus of elasticity (MOEdyn) and static modulus of elasticity (MOEstat). MOEdyn methods have been found sensitive to detect early stages of decay and may be seen as an option for non-destructive wood durability testing. As the MOEstat measurements do not change after reaching the fibre saturation point, the uncorrected MOEdyn data from ultr...
E Larnøy, G Alfredsen, H Militz
Laboratory methods for assessing the resistance of wood plastic composites to fungal attack.
2006 - IRG/WP 06-20340
Wood plastic composites (WPC’s) have many attractive material features including dimensional stability and resistance to moisture, but the wood in these materials remains susceptible to fungal attack. Assessing WPC decay resistance in laboratory trials has proven difficult because the slow moisture sorption characteristics of this material do not allow for sufficient fungal attack over the trad...
J J Morrell
CCB Preservative treatment of split muli (Melocanna baccifera ) bamboo by soaking process
2006 - IRG/WP 06-40336
This study was carried out in order to investigate the retention of chemicals inside the split muli ( Melocanna baccifera ) bamboo after preservative treatment by soaking process. Treatment with 10% aqueous solution of CCB (copper-chrome-boron) was applied in split bamboo of two sizes (1/4 part and 1/8 part) at three different moisture contents and five time periods (24, 48, 72, 96, 120 hours). It...
K Akhter, M H Chowdhury
The Influence of Extractives on Western Redcedar’s Equilibrium Moisture Content
2006 - IRG/WP 06-40331
The high natural durability of western redcedar (Thuja plicata Donn) heartwood is often attributed to the presence of the thujaplicins, which are toxic to fungi. However, sound, twenty-five year old western redcedar shakes and shingles were found to contain only traces of the thujaplicins, but significant quantities of plicatic acid (which is only weakly toxic to fungi). This suggests that factors...
R Stirling, P I Morris
The effect of wood moisture content and rod dosage on movement of boron through Douglas-fir heartwood
2007 - IRG/WP 07-30431
The potential for moisture sorption by boron rods following application to wood to affect subsequent boron diffusion was investigated in small Douglas-fir blocks conditioned to 30, 60 or 90% moisture content (MC). MCs tended to decline over the 180 day test period, but there was no evidence that the rods acted to draw moisture away from the wood. As expected, boron movement tended to increase with...
Y Cabrera, J J Morrell
Effect of barriers on moisture content of treated and non-treated utility poles
2007 - IRG/WP 07-40369
The potential for non-biocidal barriers to slow moisture sorption was investigated using butt treated western redcedar poles immersed in either water or moist soil over a 2 year period. Moisture sorption was initially slowed by the barriers, but openings at the bottoms of the barriers eventually allowed moisture to migrate upward. Moisture levels in wrapped poles eventually reached those found in...
C S Love, J J Morrell
The Role of Moisture Content in Above-ground Leaching
2007 - IRG/WP 07-50245
This paper reviews previous reports on the moisture content of wood exposed above ground and compares those values to moisture contents obtained using simulated rainfall and immersion methods. Laboratory leaching trials with CCA-treated specimens were also conducted and the results compared to published values for leaching of CCA-treated specimens exposed above ground outdoors. Previous researcher...
S Lebow, P Lebow
Control of Moisture Content in Wood Materials for Mold Growth
2007 - IRG/WP 07-10630
Mold growth on wood materials is a major concern for house owners, as it can cause health and aesthetic problems. Mold fungi, present everywhere, usually appear as black or gray patches on wood surfaces in humid environments, and are common in houses. Like any living organism, molds need food, water, oxygen, and a specific temperature range in order to grow. To avoid mold growth on wood materia...
Dian-Qing Yang
Preservative treatment of strips of Bambusa balcooa by soaking process using Borax-Boric acid
2008 - IRG/WP 08-30478
Bamboo strips made from Borak bamboo (Bambusa balcooa) were treated with 10% borax-boric acid aqueous solution by soaking process. The moisture contents of the bamboo strips were 12%, 20% and 30%. The strips were soaked for one, two, three, four and five days. The penetration of the
solution was investigated by colour test after soaking and drying. Full penetration was observed after three days ...
K Akhter, M W Sheikh, M M Rahman, T A Chowdhury, M H Chowdhury