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Stair Tread

Stair treads are constructed using an open steel grating from the flooring range with a nosing bar / sight bar welded to the front edge and drilled end plates to allow for bolting to stair stringers.

Lionweld Kennedy stair treads have been designed to help our customer comply with BS4592-0:2006+A1:2012, utilising our safegrid LK 35mm BP grating and LK 20mm BP gratings.


Where stairs are being used as a means of escape

Mesh Size Requirements

Where metal treads or landings are used for fire escapes, the gratings shall not allow passage 20mm diameter ball.


Dimensional Requirements

The minimum stair clear width shall be 1000mm unless supplied for hospitals which shall have a minimum clear width of 1200mm.



  • Stair width
    • Distance between handrails or any other obstruction either side of strings
  • Tread Length
    • Distance between stair strings (+0/-2mm)



Tread Widths

The British Standard advises a minimum going of 250mm plus a 16mm overlap which means the minimum tread width should be 266mm.  The below table gives Lionweld Kennedy standard stair tread widths for each tread type.

stair case


Nominal Standard Tread Widths
Grating TypeWidthWidth
LK 20mm BP - 3mm Bars277mm306mm
LK 20mm BP - 5mm Bars277mm306mm
LK 35mm BP - 3mm Bars-306mm
LK 35mm BP - 5mm Bars277mm306mm
LK Utility Grating - 3 & 5mm Bars277mm-
* Do not Comply with BS4592 but do comply with BS EN ISO 14122
**Other sizes available on request

Tread Lengths & Nosing Options

Tread nosing is a vital component of a stair tread because it provides multiple characteristics to the tread.  These include: –

  • Loading (loads are usually applied to the front edge/nosing of the tread)
  • Anti-slip surface to the front edge
  • Sight bar to help clearly locate each stair tread


Lionweld Kennedy offer three nosing types

stair tread
Liongrip Pyramid Nosing
Stair tread with Durbar Nosing
Durbar nosing
Stair tread with high vis nosing
High Vis Nosing













The below table gives a selection of treads and the maximum tread length. Loading criteria is available for other tread sizes by contacting our technical team on 01642 233297 or email technical@lk-uk.com.

Maximum Tread Length
Grating TypeBar sizeNosing TypeMax Tread Length
LK 20mm BP25x3Liongrip1200mm
LK 20mm BP25x5Liongrip1200mm
LK 20mm BP40x5Liongrip1505mm
LK 20mm BP25x3Durbar825mm
LK 20mm BP25x5Durbar955mm
LK 20mm BP40x5Durbar1400mm
LK 20mm BP25x3Yellow Gritted1200mm
LK 20mm BP25x5Yellow Gritted1210mm
LK 20mm BP40x5Yellow Gritted1545mm
LK 35mm BP25x3Liongrip1200mm
LK 35mm BP25x5Liongrip1200mm
LK 35mm BP40x5Liongrip1295mm
LK 35mm BP25x3Durbar620mm
LK 35mm BP25x5Durbar770mm
LK 35mm BP40x5Durbar1200mm
LK 35mm BP25x3Yellow Gritted1200mm
LK 35mm BP25x5Yellow Gritted1200mm
LK 35mm BP40x5yellow Gritted1335mm

End Plate details

Stairtreads are fitted with drilled end plates to allow them to be bolted to the supporting stringer. The drilled hole positions have been standardised across the whole range of treads, however alternative drillings are available on request.

The end plate drilling consists of one fixed and one slotted hole to allow flexibility during installation. The below sketch shows the standard end plate details.



  • Tread depth of 40mm and above have 80mm deep end plates with drillings 60mm down from the top of the tread.
  • All end plates are 5mm thick.

Building Information Modelling (BIM)

Following the government mandate on BIM level 2 requirements throughout the supply chain for all government funded projects, Lionweld Kennedy have built on our existing processes to become fully BIM level 2 compliant. Our internal processes are aligned with the requirements of PAS1192-2:2013 to ensure full BIM compliance and ensure we are prepared for fully collaborative working practices in line with specific client requirements. Using our primary BIM authoring software Tekla Structures, which is aligned to our in house manufacturing processes we have developed our comprehensive BIM object library available for download.

Login in to our BIM section to obtain: –

  • Data sheets
  • 3D Models
  • IFC Files



Contact our sales team on 01642 233299 or email sales (at) lk-uk [dot] com where an adviser will be happy to help.  Alternatively, visit our FAQ page.