Description

WIS 2/3-66 Specifying timber species in marine and freshwater construction

Specifiers have a key role in making informed decisions on the type of materials to be used in schemes. They must balance technical requirements with environmental and cost considerations. Historically, the UK construction industry has favoured a narrow range of 'tried and tested' hardwood timbers for use in marine and freshwater applications, such as ekki and greenheart. Over-reliance on a small number of species is not compatible within sustainable forest management, as certain species are being over-exploited. This is likely to reduce the security of supply and cause inflationary price pressures in the future.

This Wood Information Sheet (WIS) provides guidance on the technical properties of a number of lesser-used species (LUS) of hardwoods that may be used for marine and freshwater construction. It explains the advantages and risks of using timber in these environments and offers guidance on procurement. In order to produce cost effective, sustainable and long-lasting structures, specifiers must understand the hazards to which timber may be exposed and select the species with the most appropriate properties for the job. This WIS complements established design references, national or international standards and codes of practice.

Contents:
Background
The advantages and disadvantages of using timber in marine and freshwater environments
Biological risks
- Fungi in fresh water
- Marine borers
Non-biological risks
Timber sourcing issues
Specifying and using timber in marine and freshwater environments
- Timber properties (see explanation of tables below)
- Use classes
Structural design
- Situations where strength is critical
- Situations where strength is not critical
Promoting the lesser used species
References

The timber properties section includes two tables which outline the performance of 5 lesser used species, and of 13 non-strength-critical LUS, benchmarked against greenheart and ekki.