BS 1722-2:2020 pdf download
BS 1722-2:2020 pdf download.Expert commentary Part 2: Specification for strained wire and wire mesh netting fences.
2 Main commentary
The standard gives the minimum requirements for materials and workmanship for the more common types of strained wire fencing in order to ensure satisfactory service for the client and to assist manufacturers and installers by eliminating unnecessary variations in the demands of clients
It tijrther highlights improvements in fencing. based on the mechanics of fencing and greater use of high tensile wire in professional fencing. The previous version of the standard concentrated on the use of mild steel as the main product, which has the drawback that It has to be tensioned annually, even though this is rarely mentioned in grant or specification documentation.
The previous standard focused heavily on line wire and droppers that have in subsequent years been largely replaced by mesh netting, so the reduction of this section to a reduced number olcore infrastructure usage areas is reflected in the new Table I
The move away from concrete posts to wood and metal has seen the specifications of fencing change. and the machinery used has evolve to further change the installation process and enhance the requirements for achieving the recommended tensions. There are examples of minimum construction requirements in Clause 5. ‘lnstalLation’ with updated drawings as Figures 1 and 2.
The changes in materials, higher mechanization and the more common use of high tensile wire have benefited the end-user by enabling a fence that does not need to be tensioned annually to keep it functional, but there is an increase in requirements for materials and methods of erection to allow it to withstand the added tension on the fence line. Examples are given in Tables 3,4 and S.
The length of fence lines with mesh fencing has also increased, so reducing costs but increasing the size and functionality of straining structures needed and also reducing the individual number required to achieve the desired fence. This is reflected in the revised standard. With high tensile we have fences that retain greater sraln for a longer period. Notes on this tan be found In Subclause 5.1 of the standard.
Although mentioned in the previous version of the standard, the use of hard stapling should he eradicated as a practice. This is highlighted in the updated standard and should be included in any specifications that use wire as non-conforming practice to achieve the required service life olall strained wire fencing. Suitable attachment methods to protect the wire coating are included in the updated standard. Hard stapling Is a significant cause of wire deterioration, so weakening the life of wire fencing. Subclause 4.3.3 clearly states that wire should have free movement, and the correct use of staples is further explained in Subcla uses 5.3.1 and 5.4.2.
Hard stapling also compromises the structural integrity of a fence due to twisting. causing malfunction of strainers, so to achieve the required tension needed for the prescribed noted period it is suggested that it not be used in any circumstance, Only attachment methods for strainers highlighted in Subclause 5.4.1 of the standard should be followed to achieve a suitable fence.
As the range of wire mesh sizes has expanded from forestry and agriculture to Include a larger number of species, the introduction of species-specific mesh and the removal of general netting have resulted in more comprehensive requirements for wire mesh fencing. Table 2 clarifies the specific type of wire mesh to use for which animal group.
3 Wider context
Strained wire fencing is required to perform under varied conditions, in terms of soil types, topography, species that are to be retained or separated, and materials used. The revised standard details the requirements and recommendations to be followed to allow industry sector professionals.
