Floor construction and floor loading

Calculate the floor loads for your server with these formulas.

A floor loading assessment is the evaluation of the concrete subfloor, not the raised floor. The weight of the raised floor is considered in the floor loading formula.

The building floor must support the weight of the equipment to be installed. Although older devices might impose 345 kg/m² (75 lb/ft²) on the building floor, a typical server design imposes a load of no more than 340 kg/m² (70 lb/ft²). The following pounds-per-square-foot (lb/ft²) formula is used to calculate floor loading. For assistance with floor load evaluation, contact a structural engineer.

Floor Loading is: ( machine weight + (15 lb/ft2 x 0.5 svc clear) + (10 lb/ft2 x total area))/ total area

• The floor loading should not exceed 240 kg/m² (50 lb/ft²) with a partition allowance of 100 kg/m² (20 lb/ft²) for a total floor load rating of 340 kg/m² (70 lb/ft²).
• The raised-floor weight plus the cable weight adds 50 kg/m² (10 lb/ft²) uniformly across the total area used in calculations and is included in the 340 kg/m² (70 lb/ft²) floor loading. (The total area is defined as: machine area + 0.5 service clearance.)
• When the service clearance area is also used to distribute machine weight (weight distribution/service clearance), 75 kg/m² (15 lb/ft²) is considered for personnel and equipment traffic. The distribution weight is applied over 0.5 of the clearance up to a maximum of 760 mm (30 in.) as measured from the machine frame.

The raised floor on which the system will be installed must be capable of supporting the system's weight. Contact the raised floor tile manufacturer, a structural engineer, or both to verify that the raised floor is safe to support a concentrated load equal to one third of the total weight of one rack on a single raised floor tile. Under certain circumstances, such as relocation, it is possible that the concentrated load on a single raised floor tile can be as high as one half of the total weight of one rack per caster. When you are installing two adjacent racks, it is possible that one caster from each rack can be placed on the same raised floor tile. The load on the raised floor tile can be as high as one third of the total weight of both racks.

Depending on the type of raised floor tile, additional supports, such as pedestals, might be necessary to maintain the structural integrity of an uncut tile or to restore the integrity of a tile that is cut for cable entry or air supply. Contact the raised floor tile manufacturer, a structural engineer, or both to ensure that the raised floor tiles and pedestals can support the concentrated loads.