Nailed connections

Date Published

10 August 2022

Document Type




Nails in structures designed to Eurocode 5 can be ‘smooth’ (which in practice means smooth round nails), ‘square’ (usually square twisted nails which are frequently used for joist hangers and other light gauge metal-work) or ‘threaded’ (normally termed ‘ringed shank’ and favoured for flooring).

Smooth nails have less withdrawal resistance than the other ‘improved nails’, and their calculated resistance to lateral loading may also be less.

Where nails have to resist axial loading it is recommended that improved nails be specified. The axial withdrawal resistance of particular products must be determined by test. In the absence of test data conservative calculations methods are proposed by Eurocode 5.

Key Information

This unit outlined the use of nails in timber connections, looking at sizes and other limitations. Performances of improved nails were compared to that of smooth nails through Eurocode 5 expressions. Penetration limit requirements for different types of nails were presented with minimum timber thicknesses specified to prevent splitting failures.

Case studies

This significant and important piece of history – the only 16th Century warship together with the largest collection of Tudor artefacts in the world – is now in display in a new museum designed by Wilkinson Eyre Architects, with Pringle Brandon Perkins + Will as architect for the interior.

Tucked behind two rows of tall 1840s Victorian villas in Notting Hill, London, is a modern single-storey house with a truly dramatic roof, its exposed timber frame rising in an elegant double curve to a glazed oculus.