ISO/TC 165 - Timber structures

The purpose of this document is to extract the methods for determining the yield and ultimate characteristics and ductility of joints and assemblies from test data by reviewing existing standards in Europe, North America and Far East Asia and to provide the basic data for unifying the evaluation methods of parameters by clarifying their similarities and differences. These parameters are applied for determining the seismic performance of timber structures. This document deals with the method for determining the mechanical properties of individual joints and assemblies, and it does not refer to the seismic performance of the entire structure.

This document applies to the design of bamboo structures whose primary load bearing structure is made of round bamboo or shear panel systems in which the framing members are made from round bamboo. Except as indicated in Clause 12, this document applies to one- and two-storey residential, small commercial or institutional and light industrial buildings not exceeding 7 m in height. This document is concerned only with requirements for mechanical resistance, serviceability and durability of bamboo structures. This document permits an allowable load-bearing capacity design (ACD) and/or allowable stress design (ASD) approach for the design of bamboo structures. Allowable load-bearing capacity and allowable stress approaches may be used in combination in the same structure. This document additionally recognises design approaches based on partial safety factor design (PSFD) and/or load and resistance factor design (LRFD) methods (5.11.1), previous established experience (5.11.2), or documented ‘design by testing’ approaches (5.11.3). Other requirements, such as those concerning thermal or sound insulation, are not considered. Bamboo structures may require consideration of additional requirements beyond the scope of this document. Execution is covered to the extent that it impacts the quality of construction materials and products required to comply with the design requirements contained herein. This document provides a number of modification factors, designated Ci. These are empirically derived factors, based on best available engineering judgement, that are believed to be universally applicable to bamboo materials that are appropriate for building construction. Parameters affecting bamboo material performance are many and are addressed explicitly through the use of experimentally determined characteristic values of strength and stiffness. Annex A provides a summary of the bases upon which the provisions of this document were developed. This document does not apply to — structures made of engineered bamboo products such as glue-laminated bamboo, cross-laminated bamboo, oriented strand, or densified bamboo materials, — bamboo-reinforced materials where bamboo is not the primary load-bearing constituent. This includes bamboo-reinforced concrete, masonry and soil, or, — scaffold structures constructed with bamboo.

This document specifies methods of evaluating the effectiveness of glued laminated timber face and edge bonds within a manufacturing plant by cleaving of the glue line in both dry and wet conditions. It is not intended that it be used for initial type testing where cyclic delamination or block shear is preferred. It is based on the principle that, provided minimum wood failure percentages are met, then the bond strength exceeds the perpendicular to the grain tension strength of the under-lying substrate and therefore the bond is not the weak element limiting the integrity of a glulam assembly.

This document specifies the component performance and manufacturing requirements for prefabricated wood-based I-beams used as structural members in bending applications. It does not cover fire performance, formaldehyde requirements and biological durability. This document gives requirements for manufacturing, in-house quality assurance and periodic re-evaluation of prefabricated wood-based I-beams. Wood-based I-beams tested according to this document are intended for use in covered conditions and utilizing components that are able to resist the effects of moisture on structural performance due to construction delays or other conditions of similar severity, but not permanently exposed to the weather. NOTE The service conditions are similar to "Service class 2" as defined in ISO 20152‑1. Testing, evaluation and performance characterization requirements for prefabricated wood-based I-beams are covered in ISO 22389‑1. This document does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this document to establish appropriate health and safety practices and determine the applicability of regulatory limitations prior to use.

This document specifies requirements for establishing the characteristic properties of structural laminated veneer lumber (LVL), including 5th percentile strength values, stiffness characteristics and other performance characteristics, related to its end use as a structural product for dry use (service class 1). It is applicable to members used in flatwise or edgewise bending orientations. It does not cover the assessment of formaldehyde requirements, biological durability, fire performance or manufacturing, such as quality control and marking.

This document specifies a method based on density, for the selection of pieces of wood used in determining the strength and stiffness properties of joints between members of structural timber made with mechanical fasteners. It is intended to be used in conjunction with a test standard specifying a test method. It is assumed that the wood pieces are conditioned to the relevant conditions, that the wood density is normally distributed and that any deviations are reported. This document is applicable only to specimens of structural timber. NOTE It is emphasized that the wood density is only one of the properties that can influence the strength of a joint. Other relevant properties are, for example, growth-ring size and orientation, toughness and hardness.

This document reviews the methodologies or analytical models that have been used to develop the strength and stiffness of structural glued laminated timber (glulam) from the characteristic properties of lumber laminations. The review is limited to the methodologies used in Europe, the USA, Australia/New Zealand, and Canada as they represent different fundamental philosophies in these areas. As a result, the methodologies are not intended to be combined unless there is clear understanding of the fundamental assumptions adopted by the respective methodologies. NOTE Detailed assumptions used by the respective methodologies are available from the standards listed in the Bibliography.

This document establishes the basic principles for component performance and minimum production requirements for cross laminated timber (CLT). This document also contains scheme requirements for conformance, as provided in Annex D. The document is applicable to CLT products which are manufactured from solid-sawn timber or wood based panels built up of at least three layers in which the grain of adjoining layers are at right angles to each other. This document provides CLT dimension tolerances; component requirements; performance criteria; production, testing and trade marking guidance; and minimum requirements for factory production control. This document is based on known species, species combination and/or wood based panel structural performance and bondability. CLT qualified in accordance with the provisions of this document are intended to resist the effects of moisture on structural performance as can occur due to construction delays or other conditions of similar severity. NOTE This document does not include how CLT is to be used and installed, as it will be detailed in ISO 16696-2.

This document specifies test procedures for specimens obtained from round bamboo culms. The data obtained from the test methods can be used to establish characteristic physical or mechanical properties to be used in structural engineering design or for other scientific purposes. This document provides methods for evaluating the following physical and strength properties: moisture content, density, mass per unit length; strength properties parallel to the fibre direction, compression, tension and bending, and strength properties perpendicular to the fibre direction, tension and bending. It also provides methods to estimate moduli of elasticity in bending, compression and tension parallel to fibres, and bending perpendicular to fibres. The test methods reported in this document are intended for commercial testing applications. The test methods reported in this document are intended for commercial testing applications and can also be adopted as benchmark methods for scientific research. This document is organized to provide requirements for standard tests to be carried out to determine the material properties of full-culm bamboo as a structural material.

This document gives methods of determination of characteristic values for a defined population of mechanical connections between timber components, calculated from full scale test values. It presents methods for the determination of: a) slip modulus of mechanical connections; b) characteristic strength of connections subjected to either monotonic or cyclic loads. Glued connections are excluded from the scope of this document. NOTE 1 It is assumed that the failure mode is the same for all specimens in the sample. NOTE 2 When a small number of test results is available, ISO 12122‑6 is used for the determination of the mean and the 5th percentile values. NOTE 3 Informative commentary to the clauses of this document can be found in Annex A.

This document establishes the basic principles for rules and procedures governing the visual sorting of timber for use in structural applications.

This document provides standard test methods for determining the vertical load, axial load and torsional moment capacity as well as deflection characteristics of preformed three-dimensional joist hangers that are used primarily for securing one timber member to another (the header can be concrete or masonry). The joist hangers primarily transfer vertical loads from the supported member to the supporting member, but they can also be required to transfer axial loads from the supported member to the supporting member. NOTE 1 Structural steel sections can also be substituted as the header, but are not covered in this document. NOTE 2 One secondary mechanism to be considered is the effect of rotation of the supported member about its longitudinal axis on the joist hanger.

This document specifies grading procedures for visually and mechanically sorting round, or pole, bamboo for structural applications using such fundamental elements. Visual sorting is based on observable characteristics of the piece(s). Mechanical sorting is based on non-destructive measurement of properties known to correlate to characteristic values defining a grade. The grading procedures in this document can be used in a quality acceptance regime, although this document does not define or address acceptance criteria. This document is applicable only for bamboo that is graded in the seasoned state.

ISO 13912:2017 establishes the basic principles for rules and procedures governing the machine sorting of timber for use in structural applications. This applies to conventional bending type strength-grading machines as well as more recent machines that use other properties for strength-grading purposes.

ISO 12122-6:2017 specifies methods of determination of characteristic values for a defined population of large components and assemblies, calculated from test values. It establishes two methods for the determination of characteristic values: a) direct calculation from test values; b) calculation from a resistance model, which is firstly calibrated from test results, including calculation of error terms.

ISO 8375:2017 specifies test methods suitable for determining the following characteristic values of glued laminated timber: modulus of elasticity in bending; shear modulus; bending strength; modulus of elasticity in tension parallel to the grain; tension strength parallel to the grain; modulus of elasticity in compression parallel to the grain; compression strength parallel to the grain; modulus of elasticity in tension perpendicular to the grain; tension strength perpendicular to the grain; modulus of elasticity in compression perpendicular to the grain; compression strength perpendicular to the grain and shear strength. In addition, the determination of dimensions, moisture content and density are specified. ISO 8375:2017 is applicable to rectangular shapes of glued laminated timber.

ISO/TR 21136:2017 provides a review of key floor vibration design criteria (human acceptability criterion using calculated parameters) developed in research studies on timber floor around the world over the last 30 years. Associated design methods are provided in the Annexes. The methods proposed in this report are intended to be used for establishing human acceptability criteria for timber floor vibrations induced by walking activities. The proposed methods are applicable to the following timber floors: lightweight floors made of timber joists and thin wood panel subfloor, heavy timber floors made of heavy timber beams with a thick timber deck, and mass timber slab floors such as cross laminated timber (CLT), nail laminated timber (NLT) and glued laminated timber.

ISO 18100:2017 specifies the product and performance requirements for finger-jointed structural timber made from sawn timber elements. ISO 18100:2017 does not cover products made using impressed (die-formed) joints or finger-jointed laminations for glued laminated timber, which is covered in ISO 12578.

ISO 12122-4:2017 gives methods of determination of characteristic values for a defined population of engineered wood products calculated from test values. This document presents methods for the determination of a) characteristic value of material properties, where the determined property is multiplied by a geometric parameter to give a component capacity or component stiffness, or b) characteristic value of component properties directly, where the determined property is a component capacity or component stiffness. ISO 12122-4:2017 presents methods for determination of a) characteristic value of mean-based properties, and b) characteristic value of 5th percentile-based properties.

ISO 18402:2016 specifies test methods for determining, for use in roofs, the structural properties of double-sided load bearing structural insulated panels having - two face layers, at least one of which is a wood-based structural panel, and - a core made of a thermally insulating material having sufficient shear strength to cause the face layers to act together structurally.

ISO 12122-3:2016 gives methods for the determination of characteristic values for a defined population of glued laminated timber products, calculated from test values. It presents methods for the determination of a) characteristic value of mean-based properties, and b) characteristic value of 5th percentile-based properties. NOTE Annex B gives information on the methods that have been successfully used to estimate the characteristic values of glued laminated timber products from properties of the laminates.

ISO 19049:2016 defines the test method for horizontal diaphragms including floors and horizontal and sloped roofs under static loads. This test method is designated to evaluate the static shear capacity of a typical segment of a diaphragm under applied static loads, and to evaluate the stiffness of the diaphragm assembly.

ISO 12578:2016 specifies requirements for the components of glued laminated timber members for structural use. ISO 12578:2016 is applicable to products with a finished lamination thickness of not more than 50 mm. Although most glued laminated timber is made from coniferous species, this International Standard also applies to broad leaf species if the tests specified in this International Standard show that a satisfactory glue bond can be achieved. The basic requirements apply to structural members of all service classes; however, special precautions are necessary for service class 3, for example, the use of weather resistant adhesives (see 5.3). ISO 12578:2016 does not apply to the determination of strength and stiffness characteristics. Annex B contains informative materials for formaldehyde emission.

ISO 18324:2016 specifies test procedures to measure natural frequencies, modal damping ratios and static deflection under a concentrated load of laboratory or field timber floors. These parameters have been found to correlate well with human perception to timber floor vibration response caused by human-induced excitation under normal use. It is intended that the test procedures can be applied in lieu of calculation to quantify some or all of the above parameters that are used to evaluate the vibrational serviceability of the test floor. The subsequent use of the measured parameters to evaluate vibrational serviceability is, however, outside the scope of this International Standard. ISO published a series of International Standards on the application of modal testing and analysis to determine natural frequencies, modal damping ratios, and other dynamic properties of a structure. For the measurement of dynamic parameters such as natural frequencies and modal damping ratios, modal testing is proposed in this International Standard. It is assumed that the test operators possess the required equipment and fundamental knowledge to perform such a test. The theory of modal testing and analysis has been well documented in Reference [4].

ISO 16598:2015 provides a basic international framework for establishing structural classes for sawn timber.

ISO 13910:2014 specifies test procedures for full-size sawn timber that has been strength-graded, for the derivation of design properties in codes dealing with structural engineering design. It is applicable to sawn timber of rectangular cross-section subjected to a short-duration load.

ISO 17754:2014 specifies a test method to determine the torsional resistance to driving of screws in solid timber or glued laminated timber or other wood-based materials. The method is used primarily to ensure the torque that may be applied to install screws will be less than the specified failure torque of the screw.

ISO 10983:2014 specifies minimum requirements for the manufacture and testing of bonded finger joints in structural wood products such as glued laminated timber, cross-laminated timber, and finger-jointed timber. Although most finger joints are produced in coniferous species (softwoods), ISO 10983:2014 also applies to broadleafed species (hardwoods) where information is available to enable them to be satisfactorily bonded. It does not cover impressed (die-formed) joints and, in the case of laminated timber products, it applies only to individual laminations. Large finger joints in glued laminated timber are not covered by ISO 10983:2014.

ISO 12122-1:2014 gives methods for the determination of characteristic values for a defined population of timber products, calculated from test values. It presents methods for the determination of: characteristic value of mean-based properties; and characteristic value of 5th percentile-based properties.

ISO 12122-2:2014 gives methods for the determination of characteristic values for a defined population of sawn timber products, calculated from test values. It presents methods for the determination of: characteristic value of mean-based properties, and characteristic value of 5th percentile-based properties.

ISO 16507:2013 is applicable to determining the resistance to deflection and damage of wood-based panels subjected to concentrated impact loads from nonrigid blunt objects, concentrated static loads, and uniformly distributed loads. Surface indentation is not evaluated separately from deflection. The procedures are intended to simulate loading on roof or floor sheathing materials installed directly to framing. Three applications are covered: roof sheathing, subfloors, and single floors. Panels are tested parallel and/or perpendicular to the panel strength axis. Roof sheathing is tested in both a dry and a wet condition, while subfloors and single floors are both tested in a dry condition, as well as a condition of having dried out after being wet. These moisture conditions are those commonly experienced with site-built construction. These procedures do not cover vibration and are not intended for the evaluation of the framed assembly as a whole.

ISO/TR 20152-3:2013 describes the procedures necessary for the recognition of new wood species by ISO 20152‑1 and ISO 20152‑2 for the evaluation of structural wood adhesives.

ISO/TR18267:2013 documents the findings of a review of design standards undertaken by ISO/TC 165 to assess how an ISO International Standard for the design of timber structures might be developed and whether development of such an International Standard should be initiated.

ISO 8969:2011 specifies test methods for determining the strength and stiffness of joints made with punched metal plate fasteners in load-bearing timber structures, as follows: load-slip characteristics and maximum load resulting from the lateral resistance of the embedded projections, at various angles between the direction of the applied force and the axis of the plate (load-plate angle, α), the direction of the grain of the timber (load-grain angle, θ); the tensile strength of the plate at various angles, α; the compression strength of the plate at various angles, α (optional test); the shear strength of the plate at various angles, α. ISO 8969:2011 is linked to ISO 6891, which gives general test requirements. In addition, a method for testing the nail root in alternate bending is specified in Annex A.

ISO 20152-2:2011 specifies the performance requirements of wood bond lines in prefabricated structural timber components.

ISO 22452:2011 specifies test methods for determining the structural properties of double-sided, wood-based, load-bearing structural insulated panels (SIPs) for use in walls. It is applicable to SIPs having two face layers, at least one of which is a wood-based structural panel, and a core made of a thermally insulating material with sufficient shear strength to cause the face layers to act together structurally.

ISO 20152-1:2010 specifies the basic performance requirements for adhesives used to bond structural timber components. These requirements depend upon the service conditions according to Service Classes 1, 2 and 3, defined therein.

ISO 21581:2010 specifies static and cyclic test methods as a basis for the derivation of lateral load resisting parameters which are required in the wind and seismic design of shear walls in timber buildings.

ISO 22389-1:2010 specifies the requirements for prefabricated wood-based I-beams used as structural members in bending applications. It gives procedures for establishing and evaluating structural capacities of prefabricated wood-based I-beams. The capacities considered are shear, moment, stiffness, bearing, and flange tension and compression. Procedures for establishing common details are given and certain end-use considerations specific to wood-based I-beams are itemized.

ISO 15206:2010 specifies the requirements for grading, test methods, determination of characteristic values, methods of specifying durability and sizes of single poles manufactured from solid timber for telecommunications and electrical distribution purposes, either preservative treated or untreated, under cantilever or compression loading. It specifies the methods of measuring the sizes of solid wood poles for overhead transmission and telecommunication lines and permissible deviations that are taken into account for the acceptance of the poles; the requirements for handling and the characteristics for visual strength grading of softwood and hardwood poles, as well as the marking requirements; the methods of test to determine characteristic values for modulus of elasticity and bending strength of any population of wood poles and moisture content of solid wood poles; the requirements for durability and preservative treatment of wood poles. It is applicable to both softwood and hardwood poles.

ISO/TR 12910:2010 provides an introduction and synopsis of comparisons among the following four national design documents on light-frame timber (wood) construction: - AS 1684-1, AS 1684-2 and AS 1684-3; - the Engineering guide for wood-frame construction; - NZS 3604; - the Wood Frame Construction Manual (WFCM) for One- and Two-Family Dwellings (Chapter 1: General information, Chapter 2: Engineered design and Chapter 3: Prescriptive design). Each of the four light-frame texts compared in ISO/TR 12910:2010 is based on a national timber design standard that includes provisions for assemblies and systems, which go beyond single-member design methodology.

ISO 10984-2:2009 specifies laboratory methods for determining the embedding strength of solid timber, glued laminated timber and wood-based sheet products with dowel-type fasteners. Descriptors: timber construction, fasteners, nails (fasteners), bolts, tests, compression tests, determination, compressive strength

ISO 10984-1:2009 specifies a laboratory method for determining the yield moment of dowel-type fasteners.

ISO 16572:2008 specifies test methods for determining the structural properties of commercial wood-based and lignocellulosic fibrous panel products for use in load-bearing timber structures. These properties are intended for the calculation of characteristic values. NOTE Bamboo is an example of a lignocellulosic fibrous material.

ISO 21887:2007 defines five use classes that represent different service situations to which wood and wood-based products can be exposed all over the world. Subclasses are also defined for these use classes. ISO 21887:2007 applies only to preservatives and processes for pre-treatment of wood and wood products and is not intended for products and processes for remediation and eradication of existing damage to timber. The annex to ISO 21887:2007 provides guidance on applying use classification to specify preservative treatments, treated wood, naturally durable and modified wood but does not provide definitive specifications.

ISO 12580:2007 specifies five delamination methods for factory quality assurance of the glue line of glued laminated timber.

ISO 12579:2007 specifies a production quality-control test method for measuring the shear strength of the glue line of glued laminated timber.

ISO 16670:2003 is intended to provide a cyclic test method as a basis for the derivation of parameters which are required in seismic design of timber structures. The method includes procedures to develop the envelope curves (backbone or skeleton curves, an example is given in Clause A.5.) for joints subjected to a cyclic displacement schedule which produces representative demands imposed on the joints by earthquakes. It does not include criteria for parameters which are, at times, stipulated in national standards or building codes. ISO 16670:2003 is intended for joints subjected to lateral load and is not applicable to joints subjected to withdrawal forces. ISO 16670:2003 is applicable to joints made with mechanical fasteners used in timber structures loaded under seismic action.

Applies to joints made with mechanical fasteners used in statically loaded timber structures. Covers the conditioning of test specimens and explains the apparatus to be used for measuring the geometry of the test specimens, their moisture content and other characteristics. Details the loading procedure and specifies the details to be included in the test report.