COMEY Planchers Sureleves

This information will help you to understand the most frequently used technical criteria. For further information, consult the full standard (available from the standards management bodies).

Raised access flooring is designed and manufactured to provide mechanical resistance and stability and so that the intended operating load will not cause it to buckle or break. This is why components are tested as part of an assembly: pedestals + panels or pedestals + stringers + panels at a given height.

Load rating

The breaking load is the main criteria used for rating. In all our tests we apply a safety factor of 2 which, based on the breaking load, gives the permissible load for the raised access floors we supply.

For information 1kN = 98kg - 1kN = 100daN - 1daN = 0.980kg

Deflection rating

Deflection corresponds to the flexibility (spring effect) of the selected system. The most rigid system has a rating of A and the most flexible is rated C.

Thus if we state that a system* is rated 5A, this means that the permissible load on the system is 5N, that deflection has never exceeded 2.5mm under 5kN and that the breaking point is ≥ 10kN.
Moreover, the residual deflection must not exceed 0.5mm.
*pedestals + panels or pedestals + stringers + panels at a given height

The pedestals supporting the raised access floor panels must withstand an axial load equal to 4 times the permissible load (without being distorted or damaged).

• Detailed technical note (PDF - 37 Ko)

This DTU (unified technical document) has three separate sections:
- Technical conditions of the contract
- General criteria for the choice of materials
- Special conditions of the contract.

We list and explain the points most frequently used for the installation of raised access floors below. For further information, consult the full DTU (available from the standards management bodies).

Implementation will not be possible unless the following conditions are complied with:

- It is the project owner's responsibility to make sure that all measures are taken to ensure the premises to be fitted out are made weatherproof as soon as work begins and to ensure that the influence of the weather can be corrected inside the buildings if necessary to avoid variations in the levels of humidity.
- The ambient temperature in the buildings must be between 12°C and 24°C with a relative humidity of between 45% and 70%
- Windows shall be put in and the buildings made weatherproof.
- There must be no risk of the premises becoming damp.
- The condition of the surfaces must comply with the specifications in the paragraph on Condition of the surface of slabs and floors in standard NF DTU 21.
- The premises where the raised access floor is to be installed must be free from all objects and the ground must be swept and dusted.
- No one apart from the company's employees must be allowed to walk on the raised access floor during installation and at the earliest 48 hours after installation is complete.
- The recommended level has been clearly marked by the project owner or the project manager.

In return, the company must comply with the following data:

- Difference between the finished level and the recommended level ≤ 5mm.
- Levelness of the surface for an area of 5m x 5m (taken anywhere on the floor surface) < 3mm.
- Mismatching between two adjacent panels < 1mm.
- Flatness under a 2m ruler (taken at any point on the floor surface) < 2mm.
- if the height is > 500mm the use of a braced frame is compulsory. However, COMEY recommends a braced structure from 350mm.

- In all the following cases: heavy wall, light wall, curtain wall, windows, lack of walls, special precautions must be taken with the edge trims.
- The raised access floor installed must allow the panels to be lifted.
- If requested, equipotential bonding of the system must be performed. The company must leave the plenum clean (no off-cuts, shavings, etc.).
- The floor surface must be briefly cleaned.

• Detailed DTU note (PDF - 38 Ko)