Forty years on, and still ComFlor 46 Composite Floor Decking has it place
Walk onto almost any UK construction site and you will recognise the shape straight away: the simple trapezoidal profile of Comflor 46 composite floor decking. It is Tata Steel’s original composite floor deck, introduced in the early 1980s, still rolled today and still specified on jobs across Britain and Europe.
The reason it has lasted four decades is refreshingly simple. ComFlor 46 does the basics very well. It is nestable, easy to transport, fast to lay and economic to use. For contractors, developers and engineers who want a proven, no-surprises composite floor deck, CF46 remains a sensible first choice.
In this guide we will walk through the profile, its span capability, slab depths, fire performance and the practical reasons it still earns its place on UK floor plans. If you would prefer to watch rather than read, our short video on ComFlor 46 covers the same ground.
What is ComFlor 46?
ComFlor 46 is a composite metal floor deck. That means it does two jobs in one product.
During the pour, the galvanised steel deck acts as a permanent former and a safe working platform. There is no need for temporary shuttering. Once the concrete has cured, the same deck becomes tensile reinforcement at the bottom of the slab. One product, two structural roles.
The profile shape is trapezoidal and nestable. The sheets slot neatly into one another, a little like stackable plant pots, which means more square metres fit into every bundle and every lorry load. That simple geometry is the foundation of the transport and handling benefits we will come to shortly.
ComFlor 46 profile dimensions
ComFlor 46 has a straightforward, well-proven geometry:
- Deck depth: 46mm
- Cover width: 900mm
- Pitch: 225mm
- Crown: 67mm
- Valley: 105mm
- Available gauges: 0.9mm and 1.2mm
- Deck material: Tata Steel Galvatite hot dip galvanised steel to BS EN 10346, S280GD+Z275
The 900mm cover width is worth pausing on. Many competing profiles offer around 600mm of cover, so ComFlor 46 covers more floor area per sheet. That means fewer sheets to handle, fewer laps to detail and quicker coverage on site compared with narrower profile ranges.
How much does ComFlor 46 weigh?
ComFlor 46 is light enough to handle comfortably by hand, which keeps installation simple and safe.
In 0.9mm gauge, the profile weighs approximately 0.09 kN/m², which is around 9.2 kg per square metre. A typical 3 metre length therefore weighs roughly 25kg, so it can be carried and placed by the installation team without mechanical lifting in most situations.
In 1.2mm gauge, the profile weight is approximately 0.13 kN/m².
Always confirm the final figures against the current Tata Steel ComFlor manual for your specific gauge and length.
For more technical information, please click here.
ComFlor 46 span capability
Span is usually the first question engineers ask, so here are indicative figures taken from the ComFlor manual for normal weight concrete. These are a guide for early-stage planning only. Final spans must always be confirmed by composite slab design software for your specific loading, slab depth, mesh and fire period.
Single-span, unpropped, 1.2mm gauge, 120mm normal weight concrete slab: around 2.82m.
Double-span or multi-span, unpropped, 1.2mm gauge, 120mm slab: around 3.28m.
With a single line of temporary props during the pour, 1.2mm gauge, 120mm slab, 60-minute fire rating: around 4.85m.
That last point is the practical takeaway. Adding a single line of props during the concrete pour significantly increases the span ComFlor 46 can achieve, which can open up the structural grid without moving to a deeper or heavier profile. Whether propping suits your programme is a project-by-project decision, and our technical team can help you weigh it up.
ComFlor 46 slab depths and concrete use
ComFlor 46 is economic on concrete compared with re-entrant profiles, which helps both cost and the structural delivery footprint.
For normal weight concrete, the shallowest slab depth in the published British Standard tables is 120mm. At 120mm:
- Concrete volume is approximately 0.101 m³ per m² of floor
- Wet weight of the slab is approximately 2.37 kN/m²
In the published tables, slab depths can go shallower for lightweight concrete, with figures down to 96mm shown. If you need a shallower slab solution, this is exactly the kind of question to put to a specialist supplier. RMD Profiles has the design software to check what is achievable for your project, so get in touch before assuming a depth will or will not work.
ComFlor 46 fire rating explained
A common misunderstanding is that fire resistance is a property of the deck on its own. It is not. Fire resistance is a system, not a product.
The deck, the concrete and the anti-crack mesh or trough bar reinforcement all work together to deliver the rated fire performance. ComFlor 46 composite slabs can be designed to achieve 60, 90 or 120 minutes of fire resistance. The exact rating is governed by slab depth and reinforcement, and is calculated using recognised methods such as the Bar Fire Method or the Mesh and Deck Fire Method.
Trough bars, which are reinforcement bars placed in the deck troughs, can be used to enhance span, load capacity and fire performance together. Treat published load and span tables as a guide. If the standard tables do not quite suit your project, a specialist design can often unlock a solution that does.
Comflor 46 composite floor decking action with the steel beams
ComFlor 46 is a fully composite deck, and the benefit goes beyond the slab itself.
When through-deck welded shear studs, typically 19mm diameter headed studs, connect the slab to the steel beam below, the slab and beam begin to act as one structural section. According to SCI Publication P300, composite design of this kind can reduce steel beam weight by a meaningful margin on many floor layouts.
Less steel tonnage means a lighter frame and a lower fabrication cost. Rather than relying on a rule of thumb, run your own numbers using the free BCSA composite beam checking tool, and speak to your steelwork contractor about through-deck stud welding early in the design.
The transport and sustainability advantage of Comflor 46 composite floor decking
Here is the part that often gets overlooked when comparing flooring systems.
Because ComFlor 46 is nestable, a large area of decking fits onto a single articulated lorry. As an indicative guide, one artic load can carry in the region of 2,000m² of ComFlor 46. Compare that with a similar lorry carrying precast concrete planks, which deliver far less floor area per load.
The result is fewer deliveries, less diesel burned on structural transport and a smaller carbon footprint for the structural element of the build. To be clear and accurate: you will still need concrete wagons to pour the slab, because every concrete floor needs concrete whether it is a metal deck, precast or in-situ. But the structural delivery footprint is cut to a fraction.
For contractors thinking about sustainable construction, this is a practical, real-world benefit rather than a vague green claim. Fewer movements to site, lighter handling and efficient use of steel all add up.
Why specify ComFlor 46?
To sum up why ComFlor 46 still earns its place on UK floor plans:
- Proven with around 40 years in service across Britain and Europe
- Wide cover at 900mm, so fewer sheets and faster laying
- Nestable for low transport cost and a smaller delivery footprint
- Light to handle for safer, simpler installation
- Fully composite, working hard for both the slab and the beam
- Economic on concrete compared with re-entrant profiles
- Flexible through propping and trough bars when longer spans are needed
It is not the right answer for every job, and that is exactly why a quick technical conversation pays off. The best profile is the one that suits your grid, your loads, your fire period and your programme.
Frequently asked questions on ComFlor 46 Composite Floor Decking
Is ComFlor 46 still available? Yes. ComFlor 46 is still rolled by Tata Steel and remains widely specified. RMD Profiles supplies ComFlor 46 across the UK.
What is the difference between ComFlor 46 and CF46? They are the same product. CF46 is simply a common shorthand for ComFlor 46.
What slab depth do I need with ComFlor 46? For normal weight concrete, the published tables start at a 120mm slab. Shallower solutions may be possible, particularly with lightweight concrete. Ask our technical team for a project-specific check.
How do I get ComFlor 46 design support? RMD Profiles offers supply only, supply and design, and supply and fix packages, plus design software to check spans, loads and fire performance for your project.
Get a ComFlor 46 quote from RMD Profiles
RMD Profiles Ltd is a UK structural metal decking specialist based in Sudbury, Suffolk. We supply ComFlor 46 and the full ComFlor and MetFloor ranges, with technical support from first enquiry through to installation.
Whether you need supply only from stock, supply and design or a full supply and fix package, we can help you get the right profile onto site.
Call us on 01787 275055 or email sales@rmdp.co.uk. Send us your floor plans and loadings and we will aim to get a quote back to you within 24 hours.
