This type of weighbridge sits above of the road surface, and requires ramps on either end to allow the vehicles to access the platform. The amount of civil foundations work required is reduced for surface mounted scales, but the overall space requirement is more. Before purchasing, check the overall height of the Weighbridge. Higher decks need longer ramps, which increase the overall footprint of the weighbridge as well as the turning circle for vehicles approaching the bridge. Generally, surface mounted weighbridges require guide rails fixed on the sides of the platform, which help vehicles to be aligned centrally on the bridge. This type of installation is better suited when the bridge may need to be shifted, or for temporary (sometimes called portable) installations.
In most cases the site conditions, such as availability of space, will dictate the type of weighbridge available to you. Both surface and pit mounted weighbridges require a firm surface with load bearing capacity, the details of which will be specified in the Plan of Foundation drawings provided by the weighbridge supplier.
It may be advantageous to choose a weighbridge which has a common structural design for surface and pit mounting, this will allow future flexibility for changing the type of weighbridge.