Specifying & Ordering

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To enable us to offer the best advice and service, we recommend that our clients consider several or all of the following when ordering or enquiring about gratings:

Applications:

The application of the grating determines how the grating will be designed and should therefore always be stated when ordering.

Load requirements: The loading capacity of the grating varies with the length of the bearing direction, the bar dimension, the distance between the bearing bars and the choice of material.
Therefore, the intended type of load of the gratings should be stated when 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.

E.g. 20 x 30 mm MC x MA mm

The mesh size must be chosen based on the application of the grating. A few examples:

A public walkway grating should not have too large a mesh, we would recommend a mesh of 9x30mm with the bearing bars capable of withstanding 4KN point load over the clear span.

A light well grating must let in light but also support pedestrian traffic. A mesh no greater than 60x19 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.

Vehicle and drainage gratings may need to have small meshes to increase the strength of the grating.

 

 

The bearing direction (span) designates the width that the grating 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 bearing direction must be stated as the first dimension and preferably underlined, followed by the length of the grating.

Serrated grating - both directions.
Central Kitchien.

Holstebro Hospital, Denmark

 

 

 

Bar dimension:
If the bar dimension should not be determined based on the load, the dimension of the bearing bar must be stated as height x thickness for the bearing bar.

Grating types:
SP, N, NP, louvre gratings closed or open front.

Dimensioning of edge bars:
For edge bars, state the height x thickness and the number of sides to be fitted with edge bars.

Specification of gratings – example:

 

 

 

 

 

Example of a fixing method.

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 result in the maximum non slipness and the best 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, stainless steel or aluminium etc.

 

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

 

Fixing:

If the gratings need holes for fitting, please state the desired method: Bolt holes or notches in the edge bar Welded fixing plates Fixing clip assembly

 

Handling of the gratings:

If it is desired to handle the gratings without the use of a crane or similar devices, this should also be stated so that the dimensions/weight of the
gratings can be adapted accordingly.