Your search resulted in 18 documents.
Microbiological degradation of wooden piles in building foundations
1988 - IRG/WP 1370
White rot, soft rot and bacterial attack have been detected in softwood piles under buildings. In some cases bacteria were found to be the main degradation organisms in the studied piles. The water content of degraded piles was very high. The compression strength was quite low also in the piles deteriorated by bacteria. The density of wood was very variable, and the degree of degradation could not...
L Paajanen, H Viitanen
Durability of larch (Larix spp.) wood against brown-rot fungi
1997 - IRG/WP 97-10228
Durability of the heartwood of Larix decidua, L. sibirica, L. gmelinii, L. gmelinii var japonica, L. gmelinii var olgensis and L. sibirica x decidua against brown rot fungi Coniophora puteana, Poria placenta and Gloeophyllum trabeum was tested according to EN 113 test method. Parallel samples were used to study the amount and composition of wood extractives. The sample trees originated from the re...
H Viitanen, L Paajanen, P Saranpää, P Viitaniemi
Decay fungi in Finnish houses on the basis of inspection samples from 1978 to 1988
1989 - IRG/WP 1401
A summary of the causes and sources of fungal damages was made on the basis of decay samples and sample information sent to the Forest Products Laboratory of the Technical Research Centre of Finland (VTT) between 1978 and 1988. About 50-130 decay cases in wood structures were studied annually. In almost 50% of all fungusdamage cases the cause was Serpula lacrymans. The proportion of Coniophora put...
L Paajanen, H Viitanen
Iron promotes decay capacity of Serpula lacrymans
1993 - IRG/WP 93-10008
The influence of iron and iron compounds on the decay capacity of Serpula lacrymans was studied. Mass losses of pine wood caused by dry rot fungus were increased when FeSO4 was added into the culture medium or when there were iron nails or stone wool on the culture medium. This supports the hypothesis that iron in stone-based building materials is one reason for the increased decay capacity of Ser...
L Paajanen
A field test with anti-sapstain chemicals on sawn pine timber in Finland
1986 - IRG/WP 3368
Fourteen formulations, each in two concentrations, were tested for effectiveness against sapstain, mould and decay on Scots pine (Pinus sylvestris L.) in a field test in South-Finland. The trial was commenced in June 1985 and finished in October 1985. During the test the boards were infected mainly by mould fungi. In kiln dried boards the protective effects of nine and in green boards of four trea...
L Paajanen
Effect of mineral wools on growth and decay capacities of Serpula lacrymans and some other brown-rot fungi
1991 - IRG/WP 1481
The influence of stone wool and glass wool on growth and decay capacities of Serpula lacrymans and some other brown-rot fungi was studied. Mass losses of pine wood caused by Serpula lacrymans and Gloeophyllum trabeum were increased when stone wool was present. Glass wool had no influence on mass losses. Coniophora puteana, Serpula lacrymans and Gloeophyllum trabeum grew into stone wool and destroy...
L Paajanen, A-C Ritschkoff
Iron in stone wool - one reason for the increased growth and decay capacity of Serpula lacrymans
1992 - IRG/WP 92-1537
The chemical compositions of stone wool and glass wool were analysed. There was more iron in the stone wool than in the glass wool. It was found that iron present in stone wool was easily dissolved by oxalic acid that Serpula lacrymans is able to produce. The stone wool promoted the decay of pine wood by Serpula lacrymans. The glass wool had no effect on the decay capacity of Serpula Iacrymans. Th...
L Paajanen, A-C Ritschkoff
The effect of malt and agar trademarks on growth, decay and stilbene resistance of fungi
2000 - IRG/WP 00-20202
Effects of malt and agar trademarks used in growth media on growth of fungi in cultures, amount of decay they cause in birch samples and their resistance to stilbenes were tested. It was tested also had the conditions where fungus cultures were stored before inoculation of test plates some effect on the results. Fungi used in these tests were white rot fungus Trametes versicolor and brown rot fung...
L Syrjälä, L Paajanen, A Pappinen
Decay resistance of Siberian larch wood against brown rot fungi - Part 2. The effect of genetic variation
1998 - IRG/WP 98-10287
Wood natural decay resistance is mainly restricted in the heartwood part of tree and based on wood microstructure and chemical composition. However, the variation of decay resistant in different wood species is vide and the effect of genotype on decay resistance of Siberian larch wood grown in Finland is not known. The aim of this work was to find out the variation on decay resistance of Siberian ...
H Viitanen, L Paajanen, T Nikkanen, P Velling
The critical moisture and temperature conditions for the growth of some mould fungi and the brown rot fungus Coniophora puteana on wood
1988 - IRG/WP 1369
The growth of some mould fungi on pine and spruce sapwood was studied in 40 different constant moisture and temperature conditions. The temperature range was between +10 and +40°C and the relative humidities varied from 76 to 100% relative humidity (RH). The incubation time was 12 weeks. The mixed mould inoculation used included typical fungi growing on wood: Aspergillus versicolor, Cladosporium ...
H Viitanen, L Paajanen
Decay resistance of Siberian larch wood against brown rot fungus. - Part 3. The variation between plus trees and their grafted clones
2000 - IRG/WP 00-10350
The aim of the study was to estimate the variation in the decay resistance of Siberian larch (Larix sibirica Ledeb.) wood using mature plus trees and their grafted clones. Samples were collected with an increment core borer from 11 original plus trees and their 25-year-old grafted seed orchard clones. A typical brown rot fungus, Coniophora puteana (Schum. ex Fr.) Karst. (BAM Ebw. 15), was used as ...
H Viitanen, L Paajanen, M Venäläinen, A Harju, P Velling
Effect of crude tall oil, linseed oil and rapeseed oil on the growth of the decay fungi
2002 - IRG/WP 02-30299
The influence of crude tall oil, linseed oil and rapeseed oil on the growth of Coniophora puteana, Poria placenta and Coriolus versicolor was studied. The selected test oils were observed to have different effects on the the fungal growth. Crude tall oil inhibited the radial growth of all fungi. Rapeseed oil either accelerated or inhibited the growth of fungi depending on the type of fungus involv...
L Paajanen, A-C Ritschkoff
Repairs of dry rot damages. A follow-up survey
1989 - IRG/WP 1400
The success of repairs of dry rot (Serpula lacrymans) damage in small houses was studied by means of a questionnaire, interviews and inspections. The research material consisted of 92 buildings in the first follow-up survey and of 71 of those 92 buildings in the second survey 6 years later. In 55 buildings the damages had been repaired once and at that time the harmfulness of dry rot fungus was kn...
L Paajanen
The production of extracellular hydrogen peroxide by some brown-rot fungi
1990 - IRG/WP 1446
The role of hydrogen peroxide (H2O2) has been discussed in the degradation of wood by wood-rotting fungi. The production of extracellular hydrogen peroxide was studied by detecting the oxidation of the chromogen 2,2'-azinobis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) by H2O2 and horse radish peroxidase (HPR). ABTS and HPR were added to a solid wood based culture media. In this study ...
A-C Ritschkoff, L Paajanen, L Viikari
The effect of heat treatment on the properties of spruce
1994 - IRG/WP 94-40032
The effect of high temperature treatment (above 150°C) on the wood quality is studied at the VTT. Improved dimensional stability, lower equilibrium moisture content and increased durability against biodeterioration is achieved, depending on the environmental factors. The biodeterioration resistance of spruce is improved due to changes in chemical composition and lower equilibrium moisture content...
H Viitanen, S Jämsä, L Paajanen, A J Nurmi, P Viitaniemi
The effect of stilbenes on decay fungi of birch and aspen
2000 - IRG/WP 00-10364
Fourteen species of decay fungi, mainly species growing on birch and aspen, one leaf spot fungus of birch and the pine canker fungus Gremmeniella abietina were used to investigate how the stilbenes resveratrol and pinosylvin influence their relative growth on malt agar. With some species the ability to decay with stilbenes impregnated wood was also studied. The concentration of pinosylvin needed t...
L Syrjälä, K Von Weissenberg, A Pappinen, L Paajanen
A field study on the suitability of the European lap-joint test
2001 - IRG/WP 01-20239
Within the framework of the European SM&T Research Project "Co-normative research on field tests for wood preservatives out of ground contact in conjunction with methods for preconditioning test specimens prior to test" (FACT) one aim was to establish the suitability of the European lap-joint test (as it is described in ENV 12037:1996) to assess wood preservatives in the field in EHC 3. Scots ...
M Grinda, Ö Bergman, H-V Borck, D Dickinson, P Esser, R Gründlinger, H Leithoff, S Molnar, L Paajanen, N Pfabigan, E D Suttie, F Thomassin, T Nilsson, J Van Acker, M Van Der Zee, A Voss
Development of Wood Modification – High melting point wax and hot oil treatments
2016 - IRG/WP 16-40768
This study covers an introduction to the projects where new facilities were created for developing wood modification. In this new research environment it is possible to treat wood with versatile equipment. First modifications with this equipment are going to be done in high temperature and pressure using high melting point waxes and hot oils.
Earlier studies, tests and commercial products show...
H Turunen, L Linkosalmi, J Peura, O Paajanen