Manual for the design of timber building structures to Eurocode 5

Manual for the design of timber building structures to Eurocode 5

The Eurocode for the Design of Timber Structures (EC5) comprising BS EN 1995-1-1:
General: Common rules and rules for buildings was published in December 2004. The
UK National Annex (NA) setting out the Nationally Determined Parameters (NDPs) has
also been published. These documents, together with previously published documents BS
EN 1990: Basis of Structural Design and BS EN 1991: Actions on Structures and their
respective NAs, provide a suite of information for the design of most types of timber
building structures in the UK. After a period of co-existence, the current National Standards
will be withdrawn and replaced by the Eurocodes.

The Institution of Structural Engineers has not previously published a manual for
the design of timber structures. This Manual follows the basic format of manuals published
by the Institution for other structural materials. It provides guidance on the design of
structures of single-storey and medium-rise multi-storey buildings using common forms of
structural timberwork. Structures designed in accordance with this Manual will normally
comply with EC5. However it is not intended to be a substitute for the greater potential
range of EC5. The NDPs from the UK NA have been taken into account in the design
formulae that are presented.

Timber is a relatively complex structural material therefore a manual for the design
of timber structures is bound to be more extensive than that for other materials. Despite
its length, designers should find this Manual concise and useful in practical design. It
is laid out for hand calculation, but the procedures are equally suitable for spread sheet
and/or computer application. An example is in the design of connections; EC5 requires the
solution of a series of expressions, a process that is not practicable in hand calculations
and so tabulated values are provided in the Manual. The accompanying CD provides
connection design software and more extensive material properties.

The Manual is intended primarily for the design of buildings within the United Kingdom. Where
values and design methods specified in UK National Annexes are quoted the information given
may not be applicable elsewhere.
For the majority of design situations and materials involving timber the information required has
been provided in this Manual or in the accompanying CD.
Two principal types of timber structure are covered:
open frame buildings, i.e.
statically determinate beams and columns stabilised by bracing and/or vertical
and horizontal diaphragms
frameworks with rigid joints such as portal frames
a combination of the above
timber platform frame buildings with a maximum height of 18 metres to the finished floor

level of the top storey.

The Engineer has overall responsibility for ensuring that the strength, stability and structural
serviceability of a building and its elements will, if properly constructed, maintained and used for
its intended purpose, meet the requirements of the client and the relevant Building Regulations.
The Engineer also has a duty of care concerning durability. This is principally a matter of
suitable architectural detailing but it may sometimes require the specification of preservative or
protective treatments for timber materials and metal fastenings.
While the Engineer’s work is concerned primarily with the adequacy of load-bearing
members, components and assemblies, it might also include non load-bearing items where the

integrity of their fixing has safety implications, e.g. the attachment of external cladding.


Share this

Related Posts

Next Post »