Technical Benefits

Load Capacity

The performance of composite decked slabs is assessed from dynamic load tests carried out in accordance with BS5950 Part 4 and Eurocode 1994-1-1. Excellent load capacities up to, and in some cases exceeding 15kN/m2 can be achieved due to the shear bond developed between the concrete and the embossed metal decking. The relatively shallow slabs are typically between 130-200mm deep with light mesh reinforcement for crack control and fire. Additional reinforcement may be required in some areas to enhance load capacity or due to exposure conditions.

Fire Resistance

Outstanding fire performance can be achieved with metal decked slabs, in many cases up to 2 hours resistance can be achieved with only light mesh reinforcement in the top of the slab (A142 to A393). Where greater than 2 hours resistance is required, this can be achieved with the addition of bottom reinforcement. The achievable fire resistance period is governed by the following design criteria: deck profile, slab depth, reinforcement, concrete density, concrete grade and loadings.

Acoustic Performance

Composite decked slabs with typical floor covering provide good acoustic performance usually sufficient for office type applications. The floor build up can be detailed to include a resilient layer or concrete screed to increase the acoustic insulation where required in applications such as residential blocks, hotels and hospitals.


All our products come with a standard G120 coating (120g/m2 inc. both sides), G275 coating (275g/m2 inc. both sides). This coating provides adequate protecting for internal, dry and unpolluted exposure conditions applicable to most common applications such as offices, apartments, commercial, hospitals etc. Where composite decked slabs are exposed to direct weathering or damp conditions the decking should either be considered as permanent formwork only or additional protection should be site applied to the soffit of the decking.

Useful UK Technical References
  • SCI P056 Fire Resistance of Composite Floors with Steel Decking (2nd Edition)
  • SCI P076 Design Guide on the vibration of floors
  • SCI P078 Commentary on BS5950: Part 3: Section 3.1 'Composite Beams'
  • SCI P300 Campsite Slabs and Beams Using Steel Decking: Best Practice for Design and Construction
  • SCI P331 Design Guide on the Vibration of Floors in Hospitals
  • SCI P322 Acoustic Performance of Composite Floors
  • SCI P336 Acoustic Detailing for Multi-Storey Residential Buildings
  • SCI P354 Design of Floors for Vibration: A New Approach
  • SCI P372 Acoustic Detailing for Steel Construction
  • Concrete Society Good Concrete Guide 5: Composite Concrete Slabs on Steel Decking

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