Structural use of hardwoods
In This Series
Although the vast majority of structural timber in the UK is softwood, there is a significant interest in hardwoods from both temperate and tropical regions for structural applications. When using hardwoods in structures, the specifier may need to take more interest in the species, its origin and its moisture condition than would be the case in the routine specification of softwoods.
The term hardwood designates wood from angiosperm trees, which are flowering broad-leaved trees with enclosed seeds called fruit. Hardwood trees have a natural distribution that extends throughout the tropical and subtropical regions to the outer edges of the northern and southern temperate zones, although the range of species varies tremendously between continents and regions.
This Wood Information Sheet (WIS) covers a number of topics relating to the structural use of hardwoods including the strength properties of some of the most common hardwood species, the drying and storing process and some of the more service condition and durability factors which must be considered when specifying the species.
- Wood drying and storing
- Specifying hardwoods
- Structural design with hardwoods
- Determining structural design values
This Wood Information Sheet was revised in January 2017. Major changes have been made to reflect new and updated standards, including BS EN 350, BS 5756, BS EN 16737, BS EN 14080 and BS EN 14081-1. One of the significant changes is to strength grading, where the grade designation HS has been updated to STH, which is harmonised across Europe. The section on the marking of structural timber has also been revised to include the process of CE marking as required by the Construction Products Regulation 2011. Updates have also been made to the strength classes section to reflect changes in the standard BS EN 338.
The range of sizes available throughout Europe is large, with individual countries having different traditions as to the sizes in common use. The sawmills producing softwood timber produce a range of customary sizes. Specifying timber in these sizes is the most economic method, both in terms of material usage and...
One of the most important factors affecting the performance and properties of wood is its moisture content. The amount of water present in wood can affect its weight, strength, workability, susceptibility to biological attack and dimensional stability in a particular end use.
We estimate that over 80% of...
There is growing interest in green oak framing for a variety of reasons, from satisfaction in hand craftsmanship to the ecological advantages of using a renewable material.
This Wood Information Sheet (WIS) is an overview of the design and construction principles that specifiers should consider in order to ensure...