To enable us to offer the best service & advice, we recommend that our propestive clients consider several, if not all, of the following when enquiring/ordering gratings or planks:

Application:
The application determines everything! - Which product is best suited, which British Standard guidelines will be applicable and finally which loading criteria will be most relevant. However the clients preference regarding aesthetics will also be considered; therefore will always be asked when enquiring/ordering.

Load requirements:
The loading capacity of the grating/planks varies with the length of the bearing bar/plank height, thickness and material. Therefore, any special criteria such as vehicular traffic should always be stated when enquiring/ordering.

Standards & Regulations:
It is important to state whether the grating will be used for residential, public or industrial areas, due the different British Standards applicable to these areas.

Mesh size:
State the desired mesh size:
The mesh size is described with the distance between the filler bars as the first dimension and the distance between the bearing bars as the last dimension.

The mesh size or plank type must be chosen based on the application. A few examples:

A public walkway grating should not have too large a mesh, we would recommend nothing larger than 13mm in one direction, in accordance with BS 8300. So a mesh of 9x30mm (heel friendly) or plank type O5 (stiletto prrof) with the bearing bars/plank widths capable of withstanding 4KN point load over the clear span.

A maintenance platform for industrial use should not permit passage of a 35mm ball (35mm ball-proof) according to BS4592: Part 0: 2006 +A1: 2012. Furthermore if these platform is above an areas where people walk then the aperture size is reduced to 20mm (20mm ball proof). This is to prevent falling objects such as tools etc hurting people below. 

A light well grating within boundary must let in light but also support light pedestrian traffic. A mesh no greater than 97x34 mm would be suitable, as the aperture is within the maximum permissable based on British Standards.

Ceiling grilles may have large meshes with small bars in order to keep the weight of the grating to a minimum.

Vehicular grilles are always manufactured from a minimum of 3mm thick bearing bars and can be supplied up to 80mm deep; capable of HGV loads. We utilise our "high strength 420 Yield steel" to obtain maximum strength to weight ratio and recommend all of the bars are welded to the edge bar to avoid movement after installation. 

Bearing direction (span):
The bearing direction (span) designates the width that the grating/plank will span without support (see figure). If the grating is supported on all 4 sides, the shortest direction should be chosen as the bearing direction. The maximum clear span for a grating is 3000mm, subject to loading criteria & specification. The maximum weight of a grating panel should ideally be kept to 100Kgs. Any panels weighing in excess of this do incur higher handling costs.

Bar dimension:

If the bar dimension should not be determined based on the load, i.e. where finished floor levels or existing grilles. Then the overall height must be stated along with required bar thickness and spacing.

Grating types:
SP, N, NP, Variable & louvre gratings.

Dimensioning of edge bars:
Generally the same height as the bearing bars but can be supplied deeper to attain finish floor levels or utilised for fixing points.    

Walking direction:
When installing rectangular mesh sizes such as 9x30 or 20x30, it is important to know the walking direction to ensure that the meshes are installed correctly. This will ensure we provide the best non-slip results and visual impression. As a general rule, the primary direction of movement should be at a right angle to the longest side of the mesh.

Serrated surface:
If the grating is to be serrated, please state whether the serration should be in one or both directions.

Type of material:
Which material should be used for manufacturing the gratings:
Carbon steel, Corten A, Stainless steel or Aluminium etc.

Surface treatment:
Which post treatment should the gratings be given:
Galvanised, Powder Coated, electro-polished, pickled, Anodised etc.

Fixing:
Bolt holes or notches in the edge bar (stair treads & vertical applications)
Welded fixing plates (vehicular & public areas)
Fixing clip assembly (maintenance & industrial applications)

Handling of the gratings:
If there is a maximum panel weight required, then please state this at initial contact so we can specify correctly. Otherwise we will work within our own guidelines of 100Kgs max panel weight.