Your search resulted in 76 documents. Displaying 25 entries per page.
Weathering protection of European hardwoods through double modification
2017 - IRG/WP 17-30715
Beech and poplar were thermally modified, treated with melamine resin and both treatments were combined. The weathering performance (cracks and general appearance) of modified beech and poplar was assessed in natural weathering and correlated to material properties such as work in bending (WB) and Brinell hardness. In addition, the equilibrium moisture content after exposure of 12 months and subse...
G Behr, A Gellerich, S Bollmus, H Militz
Review on protection of timber bridges in Norway and other countries
2017 - IRG/WP 17-40809
Wood plays a major role in design and construction of modern bridges in Norway. Typical elements of those bridges are double impregnated glued laminated members, stress laminated timber decks, slotted-in steel plates, metal cladding of the surfaces of loadbearing members, and cross girders made of steel. Selected examples of timber bridges in Norway are presented. This review paper gives an overvi...
K-C Mahnert, U Hundhausen
Durability of energy efficient wooden buildings: a building physical point of view
2017 - IRG/WP 17-40812
The drive for more energy efficient and sustainable buildings resulted in an increased popularity of wooden buildings, even in countries with a masonry tradition. Often guidelines and prescriptions then are copied from other countries. Different climatic boundary conditions and tradition of finishing, though, do require different moisture tolerance criteria. This is clearly the case for water vapo...
S Roels, J Langmans
Above-ground testing methods – review of Rotorua, New Zealand test site results after ten years
2018 - RG/WP 18-20642
A series of seven different types of above ground durability tests were initially conducted over four years to determine which type of tests would give the fastest, most consistent results. Five types of test; ground proximity, two types of decking, flat panels and double layer, were reassessed after ten years. Exposure conditions varied between tests with ground proximity producing close to groun...
D Page, T Singh
Self-Extinguishment Phenomena of Mass Timber in Medium-Scale Compartment Fires
2018 - IRG/WP 18-30729
This paper presents a review of the fire safety risks that mass timber construction may introduce in buildings, with special consideration to medium- and high-rise buildings. These main risks are represented by an effect to the classical fire safety strategy for buildings: (1) Compartmentalisation, to ensure that the fire will not spread farther than the compartment of origin, (2) Preventing verti...
C Gorska, J P Hidalgo
Development of accelerated decay test for CLT using a fungus grown on agar medium
2019 - IRG/WP 19-20664
CLT is a large-scale wooden board which consists of several layers of sawn lumber stacked in altering directions. Therefore, a lot of large cross sections appear on all narrow faces of CLT. As water penetrates easily into timber from cross section, wooden material whose cross section is exposed to water in in a usage environment is susceptible to deterioration by organisms. Wood deterioration orga...
T Miyauchi, K Kambara, W Ohmura, T Mori, H Matsunaga, N Hattori
Durability testing of mass timber building elements: a call for a collaborative trial
2019 - IRG/WP 19-40875
Mass timber buildings have captured the imagination of architects and engineers seeking more environmentally friendly building materials. The mass timber movement has tremendous potential to markedly increase timber use in mid-rise to high rise buildings. With great promise, however, comes great risk. Most mass timber structures that have been built or are being planned use no protective treatm...
J J Morrell
Experimental study on compressive strength performance of cross laminated timber with biodeterioration damage
2019 - IRG/WP 19-40883
The mass timber construction has attracted attention around the world. The reasons are due to the environmental impacts and the potential of the strength performance and quantity of the wood. Nowadays, CLT is one of the most important materials for the timber constructions. If we use CLT as a building material, we should consider the biodegradation risk for long time use. From an estimation of fut...
T Mori, Y Otsubo, R Inoue, M Ikeda, K Kambara, W Ohmura
Future development of durability assessment of wood, according to typical usage of preservative-treated wood and naturally durable wood in Japan
2020 - IRG/WP 20-20675
A market of preserved wood products in Japan has two unique histories. First is the market shift to residential ground sills from utility poles and sleepers; the other is the stop of CCA treatment caused by the new effluent standard. In 2018, around 85% of preserved wood products used for residential ground sills were treated with non-CCA such as Cu-based agents. Since the market of treated wood h...
T Osawa, W Ohmura, H Kurisaki
Preservative Treatment of CLT: An Example at Shimojishima Airport
2019 - IRG/WP 19-30748
Cross laminated timber (CLT) is a relatively new construction method that allows multi-storey construction using solid wood instead of concrete or steel. It is a method favoured by progressive architects and recognized for its much lower environmental footprint. Wood is an excellent construction material and is a long-term carbon sink that also performs well in the event of earthquakes and fire....
J Lloyd, N Yamashita, A Taylor
Estimation of residual compressive strength on cross laminated timber with biodeterioration damage
2021 - IRG/WP 21-40918
CLT is susceptible to biodeterioration such as fungal decay and termite attack during long-term use for buildings. It is necessary to know the residual strength performance of biodegraded CLT for estimating future performance and aging of CLT. In this study, compression tests of CLT damaged by brown rot fungi and termites were conducted to clarify the relationship between residual strength and mas...
R Inoue, T Mori, K Kambara, W Ohmura
Preliminary investigation for preservation method of CLT using non-pressure treatment
2021 - IRG/WP 21-40919
Cross-laminated Timber (CLT) is increasingly being used in residential and non-residential construction around the world, and some of these areas are at high risk of biodeterioration. Addition to moisture management of construction, preservative treatment of CLT may be needed to prevent decay and termite attack in the area. Pressure treatment being most reliable, is not feasible due to the large d...
T Miyauchi, Y Ohashi, J Miyazaki, R Takanashi, H Shibui, S Isaji, T Shigeyama, Y Sugai, A Yamamoto, T Hramiishi, T Mori, H Matsunaga
Carbon footprint of a cross laminated timber building – Torvbraten school case study
2021 - IRG/WP 21-50366
Torvbråten school is a public school in Asker, Norway, that has reached many sustainability goals. The school was the second in Norway to have Nordic Swan Ecolabel and has a 60 % reduction in carbon footprint compared to the reference benchmark. The building is made of cross laminated timber (CLT) and extensive wood use in general. From a wood protection viewpoint, will this sustainability sustai...
L G F Tellnes, J K Naess, M R Hanssen, P-O Flate
Post-layup protection of mass timber elements in above ground protected exposures: 2-year results
2022 - IRG/WP 22-30766
Mass timber has seen increased use as a building material for low and mid-rise construction in recent decades. The durability of mass timber elements has not been fully examined and the effects of wood destroying organisms on this these materials merits attention. The effectiveness of currently labeled soil termiticides and passively applied biocides at post-construction or as remedial agents need...
M E Mankowski, T G Shelton, G T Kirker, J J Morrell
Utilization of Pressure Treated Lumber in Cross Laminated Timber Manufacture and its Impact on Bondline
2022 - IRG/WP 22-40953
Mass timber building construction is increasing dramatically across North America which presents challenges to these structures not seen in Northern Europe. Large parts of the United States harbor termites and existing mass timber building technologies that rely solely on moisture exclusion to increase durability are insufficient in these areas. The successful expansion of mass timber construction...
G Presley, C Wainscott, J Valenti, S Noble
A Comparison of Cross-Laminated Timber (CLT) Floor Panels using Finite Element Analysis and Experimental Fire Testing
2022 - IRG/WP 22-40955
Cross-laminated timber (CLT) is a relatively new timber product and has gained popularity in North America and Europe as a construction material. As a sustainable engineered timber product, CLT offers many advantages over solid wood, concrete, or steel construction. However, the use of timber in medium to high rise buildings is often avoided mainly due to its combustible nature. In this paper, a n...
M Yasir, A Macilwraith, K Ruane
Surface treatment of cross-laminated timber to improve water repellency and UV resistance
2024 - IRG/WP 24-20716
Cross-laminated timber (CLT) has emerged as a revolutionary building material, offering a sustainable alternative to traditional construction methods. By layering and bonding multiple layers of wood at right angles, CLT creates a robust and versatile structural element capable of supporting significant loads while promoting eco-friendliness and design flexibility. However, despite its numerous adv...
M Chen, S Uphill, J Hilsenbeck, A Hughes
Evaluation of the water exclusion ability and inherent bioactivity of heartwood against decay in Japanese and European wood species via above-ground exposure and water absorption tests
2024 - IRG/WP 24-40998
The natural durability of wood has been thought to mainly depend on bioactive extractives and the water exclusion ability. To clarify the contribution of each factor to wood durability, above-ground exposure tests were conducted on Japanese and European wood species. A double-layer test was carried out using heartwood specimens of four wood species, i.e., Japanese cedar, Japanese cypress, Scots pi...
T Osawa, R Noda, K Yamamoto
Evaluation of vacuum borate treated spruce or pine CLT in an above ground protected test in southern Mississippi
2024 - IRG/WP 24-41001
Cross laminated timber (CLT) has become a popular wood composite in large building applications that were previously limited to concrete and steel. To extend service and prevent biological attack, chemical protectants are often applied to wood. Cross laminated timber panels are not typically treated, in part due to a lack of data on efficient and effective methods for treating large panels. Ther...
M E Mankowski, A Taylor, G T Kirker
Evaluation of mass timber materials for military and commercial trailer decking
2024 - IRG/WP 24-41009
In this study, CLT trailer decking was manufactured to current military trailer decking specifications, verified using PRG320 performance criteria, and treated with either waterborne or oil borne wood preservatives. Preliminary results show adequate uptake of preservative solution and subsequent testing shows minimal effect due to treatment. Field durability tests are also being conducted of treat...
G Kirker, A Senalik, X Wang, K Ohno, R Arango, M Mankowski, X Xie, J Eskola, N Kamprath, S Karwaczynski, M Weaver
Performance of Douglas-fir cross laminated timber (CLT) subjected to elevated humidity in a ground proximity field test for 6 years
2024 - IRG/WP 24-41010
The ability of insecticidal soil drenches or spray-on insecticide/fungicide treatments to protect mass timber elements exposed in a high moisture environment but out of direct soil contact was assessed using a modified AWPA ground proximity test established in 2017. Three-ply Douglas-fir CLT pieces measuring 305 x 355 x 105 mm (L x H x W) were installed at the Harrison Experimental Forest (HEF) (S...
M E Mankowski, J J Morrell, T G Shelton, G T Kirker
Moisture uptake in CLT during the construction phase: real construction conditions versus specimens exposed to environment
2025 - IRG/WP 25-41019
The rapid growth in the use of Cross-Laminated Timber (CLT) in construction highlights the need to address durability concerns, particularly in regions with less experience in Mass Timber Construction and favourable climatic conditions for the biological degradation of wood, such as Mediterranean countries. A lack of awareness and deficient construction management can negatively impact the public ...
D Lima, S Duarte, J M Branco, L Nunes (†)
Evaluation of moisture exclusion ability of wood using double-layer outdoor exposure tests
2025 - IRG/WP 25-41021
The material resistance of wood to decay must be due to the combined effects of heartwood extractives and the moisture content state. Evaluating the moisture exclusion ability of wood is important for assessing its durability in outdoor use. We conducted previously double-layer outdoor exposure tests and investigated the relationship between moisture content over time and the progress of decay usi...
T Osawa, R Noda, K Yamamoto
Linking treatability with moisture dynamics
2025 - IRG/WP 25-41031
Wood preservation is inherently linked to the ability to penetrate treating liquids. The EN 147374 (2022) standard provides a methodology to assess treatability and allows to identify wood species in relation to treatability classes. Over the past decades, performance of wood species in applications in use class 3 has been linked both to the impact of moisture dynamics and the resistance against f...
J Van Acker, K De Vriendt, M Durimel, L De Ligne, J Van den Bulcke
Durability evaluation of outdoor-exposed CLT treated with various wood presevatives using CT scans
2025 - IRG/WP 25-41035
Methods for wood preservation treatment of large materials such as Cross Laminated Timber (CLT) are limited. It is unclear which wood preservation treatment methods can effectively protect CLT from rot risk. In this study, accelerated rot tests (fungus cellar test) of CLT treated with the solvent-borne wood preservative by non-pressure treatment, named ‘deep penetration treatment’, were conduc...
Y Sakurai, T Shigeyama, Y Sugai