Dimensions

Dimensions in mm.

The minimum width is 1000 mm.  The maximum width is 1549mm.
Please contact us for details for any other non-standard dimensions.

Tolerances

Tolerances for wide strip and slit wide strip comply with standard EN 10051:2010.
Tighter tolerances are available, please contact us.

Using Durbar^®

Durbar is a non-slip raised pattern floor plate of integral manufacture (the pattern is rolled in not welded). The "tear drop" studs are distributed to give maximum slip resistance in a variety of applications whilst ensuring a free draining surface.

The nominal gauge of Durbar is the thickness of the plain plate exclusive of pattern.

Unit Area Density

Capacity Tables

It is usual to consider floor plates as supported on all four edges although stiffeners or joint covers may only support two edges. If the plates are securely bolted or welded to the supporting system, they may be considered as encastré. This increases the load carrying capacity slightly but reduces the deflection considerably.

The thickness given is exclusive of any raised pattern i.e. on plain.
The breadth is the smaller dimension and the length the greater, irrespective of the position of the main support members.
The maximum uniformly distributed load on the plate (w) is given by Pounder's formula and the maximum skin stress is limited to the design strength p_y

For calculating the maximum deflection (d_max) at serviceability, the uniformly distributed imposed load (w_imp) on the plate is derived as follows.

w = g_dead w_dead + g_imp w_imp
w_imp = (w - g_dead w_dead)/ g_imp

For plates simply supported on all four edges

This formula assumes that there is no resistance to uplift at plate corners.

w = a₁ p_y t² / k B² [ 1 + a₂(1-k) + a₃(1-k)²]
d_max = a₄ k w_imp B⁴ [1+a₅(1-k) + a₆(1-k)²] / E t³

Where resistance to uplift at corners is provided, the above formula will be conservative. Higher values may be obtained by assuming encastré status as outlined below.

For plates encastré on all four edges

The plate must be secured to prevent uplift, which would otherwise occur at the plate corners.

w = a₇ p_y t² / k B² [ 1 + a₈(1-k) + a₉(1-k)²]
d_max = a₁₀ k w_imp B⁴ [1+a₁₁(1-k) + a₁₂(1-k)²] / E t³

Where:

L = length of plate (mm) (L > B)
B = breadth of plate (mm)
t = thickness of the plate on plain (mm)
k = L⁴/(L⁴+ B⁴)
p_y = design strength of plate ( 275 N/mm² or 355 N/mm²)
E = Young's modulus (205 x 10³ N/mm²)
1/m = Poisson's ratio (m = 3.0)
g_dead = load factor for dead load (1.4)
g_imp = load factor for imposed load (1.6)
d_max = maximum deflection (mm) at serviceability due to imposed loads only
w = uniformly distributed load on plate (ultimate) (N/mm²)
wdead = uniformly distributed self weight of plate (N/mm²)
wimp = uniformly distributed imposed load on plate (N/mm²)
a₁ to a₁₂ are constants as below:

Durbar ultimate load capacity –various sized plates

Fixed on all four sides (encastré)

The ultimate uniformly distributed load for various sizes of Durbar plates fixed on all four sides and stressed to 275N/mm² can be determined by using the table. The values are based upon equations developed by C.C. Pounder and conform to the construction and fixing requirements in BS 4592-5 : 2006.  The values in the tables are theoretical; in-use performance may vary. This information should not be used without the advice of a qualified structural engineer. Users of this information should satisfy themselves that it is suitable for their purpose.

Ultimate load capacity (kN/m²) for Durbar fixed on all four sides and stressed to 275N/mm² 

Values obtained with plates secured to prevent uplift

^†. Stiffeners should be considered for spans in excess of 1100mm to avoid excessive deflections.
^§. Loads have been limited so that deflection ≤B/100 at serviceability, where serviceability is due to the imposed load only

Fire safety

Reaction to fire

Durbar hot-rolled steel floor plate is non-combustible and has a fire rating of A1 (and A1FL for flooring). This applies to both the UK and Europe. It qualifies as a Classification Without Further Testing (CWFT) material mentioned in Approved Document B (Fire safety) Volumes 1 and 2, and set out in EC Decision 96/603/EC. These materials have known behaviour during a fire, and therefore do not need to undergo additional testing. 

A1 and A1FL are the highest ratings achievable; materials with these ratings are non-combustible and will not contribute to a fire through their own degradation, nor will they generate smoke or burning droplets during a fire.

Resistance to fire

Fire resistance ratings are determined via testing, according to various standards (including but not limited to BS EN 13501-2, BS 476-21, BS 476-22 for the UK and EU). The regulations may require a specific application to be submitted for fire resistance testing. It is the responsibility of the customer to ensure that any form of construction which includes Durbar floor plate meets the required fire resistance rating.

Fire resistance ratings are required within buildings in many, but not all, situations; this includes load bearing elements of construction such as floors. These requirements vary for different scenarios and building purpose groups. Fire resistance ratings are not always required under certain circumstances, for example; platform floors, external horizontal and external vertical means of escape, and raised storage areas in single-storey buildings used for storage and industrial purposes.

The customer must satisfy themselves that they comply with the relevant national requirements for fire resistance ratings. These and any exclusions are detailed in Approved Document B (Fire safety) Volumes 1 and 2 for the UK.

Unique self-draining stud pattern provides a slip-resistant surface
 

Keeping you safe

According to the UK Health and Safety Executive (HSE), over a third of all major injuries reported in the UK each year are caused as a result of a slip or trip¹. That amounts to 172,000 injuries to workers every year, not counting injuries to the general public.

Products that contribute to safer passage over surfaces, can reduce the risk of slips and trips, whether in permanent conditions, such as in factories, or temporary conditions, such as construction, building and planned maintenance.

The dense pattern of studs on Durbar creates a slip-resistant surface at all angles and allows plates to be used in any direction. Durbar has a unique diamond pattern which, on average, is 23% deeper and has 10% more studs than other generic steel floor plates.
 

Tested and trusted

In recent independent tests carried out on genuine Durbar floor plate, slip resistance was found to be consistently good, in both dry and wet conditions.

The UK HSE and the influential UK Slip Resistance Group (UKRSG) recommend the use of a pendulum test to measure the slip resistance of flooring products. This test is according to EN 13036-4. The pendulum test measures the dynamic coefficient of friction and is designed to replicate a pedestrian heel strike. This has been found to best simulate the most common cause of slips.

Independent tests on genuine Durbar using the pendulum tester according to EN 13036-4 have shown consistently goodresults in both wet and dry conditions². The measured pendulum test value (PTV) in the wet condition of 46 represents a ‘Low’ slip potential, according to UKSRG guidelines, while in the dry condition, a PTV of 73 provides a classification of ‘Extremely low’ slip potential.

Comparative tests on generic floor plate adopting either ‘T’or ‘A’ patterns have shown that the unique pattern of studs on genuine Durbar results in the lowest all-round slip potential.

The actual slip resistance of Durbar or any other floor plate willdepend on real-life application and the environment in which it is used. Galvanising, painting or coating Durbar can influence the slip resistance.

Pendulum test comparison

The table below, taken from UKSRG guidance, represents the risk category for a reasonably active pedestrian between 18 and 60, walking in a straight line on a level surface.

^1. UK Health & Safety Executive Statistics, 2017/18 ; non-fatal injuries to workers according to self-reported estimates from the Labour Force Surve
_2. External laboratory results performed according to BS EN13036-4 BS7976 / UK Slip Resistance Group guidelines, Wessex Precision Instruments Ltd, July 2019

Frequently Asked Questions (FAQs)

What is the fire resistance of Durbar?

Durbar hot rolled steel floor plate is classed as non-combustible. When subjected to extreme heat, Durbar has distinct advantages over some other flooring materials. At temperatures where aluminium alloys have already begun to melt, Durbar steel floor plate will still be supporting design loads. The fire performance of an assembly is specific to the construction of that assembly and so we strongly recommend you check your fire rating with a qualified fire engineer.

What is the slip resistance of Durbar?

Durbar has been tested to BS 7976-2:2002 for slip resistance and found to have Extremely Low slip potential in the dry state and Low slip potential even when wet. The unique Durbar pattern ensures this optimised slip resistance and in comparison tests, competitors’ floor plate products display a lower slip resistance.

Will galvanising and painting Durbar affect it’s characteristics?

Independent testing, in both wet and dry conditions in accordance with BS7976-2 assessed as-supplied Durbar as extremely low slip when dry, and low slip when wet. Moreover, Durbar is self-draining.

Galvanising and/or painting will alter the surface condition,  and thus the slip resistance – we suggest you  should consult the paint manufacturer for details of appropriate paint systems. 

Can Tata Steel provide calculations for my specific use case of Durbar?

Durbar is stronger than ordinary mild steels, easily fabricated, and therefore well suited to performing a structural role efficiently. We provide load capacity tables for typical configurations of Durbar in the Design section of this web-page, which cover a range of representative cases. For specific use cases, we recommend that you consult an independent design engineer.

Can I buy individual sheets of Durbar from Tata Steel?

We manufacture Durbar in coil form and can supply both coil and cut sheet. We are the largest distributor in the UK of Durbar in a cut-sheet format. We supply Durbar sheet to an extensive range of local stockists that can provide product in appropriate sizes and quantities for specific end use requirements and projects

Is Durbar a sustainable choice?

Durbar is a structurally efficient choice for slip-resistant, hard-wearing and long-lasting flooring. Compared to some alternatives, less supporting structure is required. Durbar itself is 100% truly recyclable steel – indeed every sheet of Durbar includes a significant proportion of recycled steel.

Durbar has been in use in structures for over 50 years and remains the benchmark in textured floorplate in the UK – the ability to match the pattern with existing material in use makes it excellent for prolonging the life of existing structures.