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Image showing Z-purlin as it exits the production line

Hayes Cladding's range of Z-purlin sections provide flexible structural solutions to varied  cladding support systems and can be used as part of a roofing support system or as side rails for vertical (wall) cladding applications. 

Z-purlins are cold formed structural sections, manufactured from high tensile Z39 steel and are pre-galvanised so no additional finish is required. This product satisfies the requirements of BS5950: Part 5 (1998). Their high strength to weight ratio (as with all our cold rolled sections) enable practical substitution for hot rolled steel sections whilst easing handling on-site and during installation. The 'Z' in Z-purlin relates to the shape of the section and the structural strength of this product is mostly attributed to the shape.


  • Pre-Galvanised - no additional finishing or painting required

  • Pre-punched holes -minimising assembly time and errors

  • Wide range of sections, gauges, spans and ancillary items to suit an array of applications

Image showing a Z-purlin hot off the production line


  • Roof PurlinsDepending on the application, Z-purlins can be used in a single or double span arrangement. They are ideal for Heavy Bay End sleeved and butted systems. The design of our Z-purlin range ensures flexibility so can be used with a wide range of hot rolled sections in addition to other cold rolled products and profiled sheeting.

  • Side rail / Sheeting rails -  Offering comparable performance to our C-sections, Z-purlins can be used as side rails which simplifies the specifying and ordering process.


The diagrams below refer to all Z-section sizes (Z-140, Z-170, Z-200 and Z-240). The dimensions for a specific Z-section can be referenced in the table below. Click here to download CAD drawings for any of our products.

Diagram showing dimension place holders for dimensions of all section sizes



Diagram showing dimension place holders for dimensions of all section sleeve sizes

Diagram showing dimension place holders for dimensions of all section sleeve sizes

 Z-Section Sleeve


Section A B C D E F G H I K L M
Z-140 56 20 140 50 20 70 29 300 64 37 33 35
Z-170 66 20 170 60 20 100 29 300 64 37 33 35
Z-200 66 20 200 60 20 130 29 364 64 37 33 35
Z-240 65 20 240 59 20 170 29 433 64 37 33 35


Fixing Details

Purlin butted system

Used in the butted system, two Z-purlins are fixed using a cleat (the cleat is welded or bolted to the hot rolled steel section). This system is suitable for single bay or low loading applications with up to 8m spans. It is also compatible with other cladding support systems.


Purlin sleeved system

This system is used primarily for spanning over two or more bays. The sleeved system incorporates a cold rolled sleeve to which two Z-purlins are bolted to the cleat. This system will cater up to 12m spans depending upon the loading of the cladding etc. For technical advice, contact our sales department.


Side rail butted system

As with the purlin butted system, Z-purlins used in a side rail application can be fastened directly to a cleat, which itself can be bolted or welded to the hot rolled section. Again, this is suitable for smaller buildings, short or uneven span or light loading applications.


Side rail sleeved system

Like the purlin sleeved system, Z-purlins used in a side rail application cater for spanning multiple bays or supporting heavier loads with the incorporation of a sleeve, fixing the purlins to the cleat. This significantly increases the loading capability of the system.


Click here to view load span data of all systems for various spans.

Additional Fixing Details

The following fixing systems apply mostly to sleeved purlins used in multi-bay or heavy end bay applications.

Staggered Sleeve Arrangement (Double Span)

Using a staggered sleeve arrangement increases the loading capabilities of the system in comparison to the butted system, whilst still offering a cost effective solution. In the diagram below you can see the staggered arrangement of sleeves. Care must be taken during installation to maintain erection sequence.

Diagram showing the staggered arrangement of sleeves in a Staggered Sleeve Arrangement

Heavy End-Bay Double Span

Using this system, sleeves at the ends of the span are positioned at every support. Internal bays have sleeves staggered on alternate supports and utilise lower gauge (thinner) sections and sleeves. The effect of staggering reduces the number of sleeves required and therefore the number of installation components, whilst still retaining most of the strength of a sleeved single span system.

Diagram showing arrangement of sleeves in a Heavy End Bay Double Span system

Application Examples

Below you will find examples of Z-purlins used in different applications.

Image showing Z-purlin arrangement at the apex of the roof

Image showing two Z-purlins at the apex of the roof on which roofing sheets on either side of the apex are placed, flush to the apex. An external ridge is fixed on top of the sheets to prevent water ingress.

Image showing horizontal Z-purlin at the gable end of the building envelope

Image showing horizontal roof Z-purlin at the gable end of the building envelope




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