Serviceability states and deflection criteria outlined by MCRMA

In structural engineering, serviceability refers to the conditions under which a building is still considered of use. Should these limits be exceeded, a construction that may still be structurally sound would nevertheless be considered unfit.

It also considers conditions other than the building strength which may render a building unusable; such as durability, overall stability, fire resistance, deflection, cracking and excessive vibration.

MCRMA recommends that appropriate and workable serviceability states and deflection criteria should be agreed at the outset.

When applied to the primary structure, secondary structure and the building envelope, it will ensure that all elements of the building perform as expected. It will also certify that the interface, interaction and fit between components and systems meet with expectations.

Without these criteria, the construction will not perform correctly and the installation and attachment of component parts by follow-on trades might be compromised.

MCRMA believe adapting to the Guidance document on serviceability states and deflection criteria could lead to better and more consistent standards of metal roofing and cladding construction.

A PDF of the guide can be downloaded here.