Cellular Beams | Kloeckner Metals UK | Kloeckner Metals UK


Cellular beams are the modern form of the traditional Castellated Beam. Westok cellular beams comprise a lightweight, low embodied carbon beam formed by profiling a rolled section using our patented, semi-circular dual pass process.

The two tees are separated by half a pitch and the beam is welded back together. The resulting cellular beam has a continuous string of circular or elongated cells along the full length of the beam.


  • The Westok Cellular Beam is used in applications where there is a requirement to achieve one or more of the following:
  • Economic clear floor and roof spans
  • Economic alternative to truss and portal frame solutions 
  • Shallow downstand floor beams, where rolled sections have insufficient capacity
  • Service integration and/or assistance with the building ventilation strategy by utilising the cells within the depth of the beam
  • An aesthetic exposed structural steelwork solution





There are essentially an infinite number of possible cellular beams which can be formed in depths of 1mm increments. The overall beam depth, cell diameter and spacing can be tailored by the designer to best suit the application.



The top and bottom tees are frequently cut from different rolled sections, with the resulting asymmetric Westok beam formed with each tee/flange designed to suit the load it resists and the restraint conditions which apply locally.

This is particularly beneficial in composite construction, where the concrete slab resists most of the compression in the composite beam. This permits a much smaller and lighter top tee to be used. Also, where lateral torsional buckling of either flange is the key design check, the tee can be sized appropriately to suit.



A cut-down Westok Cellular Beam is used when the designer faces an onerous depth restriction and cannot use a traditional rolled section as it has insufficient capacity.

Frequently depth restrictions require engineers to design shallow floor beams to span long distances and to carry heavy loads. The overall depth of the Westok beam is shallower than the parent section, however the beam has significantly enhanced section properties compared to a rolled section of equivalent depth.

To aid this process, the Cellbeam software package can be used to design an automated beam of fixed depth to match the restriction faced by the designer.




Minor modifications to the profiling process can allow curved and tapered beams to be manufactured.

Curved and tapered Westoks are very popular applications of our beams.


The patented profiling process leads to a beam with a continuous string of cells along the full length of the beam. The beam is therefore, very flexible in terms of the provision of cells for service integration.

Elongated cells can be readily provided where there is a requirement to pass rectangular shaped services through the beam.

As the entire beam comprises web penetrations, there is much freedom to accommodate changes/additions to the future service integration needs.


The continuous string of cells is also beneficial in assisting the ventilation strategy of the building, where the web penetrations maximise the potential for air-flow through the beam.

We would be happy to help if you have any questions or queries, please get in touch.

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