A Contractor’s Guide to Raised Access Floors

A raised access flooring system installed as a bare panel will normally be either a wood (particleboard) finish or galvanised steel, other finishes may be encountered but all metal surfaces must have an anti-corrosion finish.

It is rarely the responsibility of the flooring contractor to install the panels, but the following information is of value in ascertaining it has been installed correctly and is fit for purpose.

Alternatively, the floor panels may have a factory bonded finish e.g., a resilient floor covering such as PVC (vinyl), rubber, etc, needle punch, carpet, laminate or may be engineered to accept a textile finish that incorporates a location system. Sheet or broadloom materials should be avoided since this system is designed to give easy access to underfloor services.

Protection

Where raised access metal clad panels are supplied with adequate corrosion protection which requires all parts of the platform floor system to be installed free of rust, corrosion, rot or any form of deterioration: they should be suitably finished to prevent such deterioration in normal use and oxidation, or rusting should not occur.

Raised access floors are often installed before other trades have completed their work, therefore adequate protection should be provided to ensure there is no damage to the surface which is essential to ensure satisfactory installation. Where metal clad panels are supplied with inadequate corrosion protection, they may rust whether or not floor coverings are installed. However, trapping moisture under floor finishes which is unable to evaporate and allow the panel to dry, appears to accelerate the corrosion process.

Water Tightness

Unfortunately many raised access panel floors are installed too early in the construction programme due to inadequacies in the planning or progress and sometimes before the building is watertight. Those supervising the construction process should ensure that this does not occur and ensure that the flooring contractor does not have to resolve the problem.

Residual Construction Moisture

Installing floor coverings onto raised panel floorsdoes not, in itself, require hygrometer readings to be taken. Retention of moisture in the structural slab and in the space underneath the raised panel floor deck that allows air circulation is often a primary source of moisture which can cause problems and must be avoided.

Wet Extraction and Spillage

It is almost inevitable that during the life of a floor covering, on raised panel floors, that wet spillage and wet extraction cleaning will occur. Where panels are adequately protected from corrosion, problems should not occur.

However, it should be noted that wetting of the floor covering may be deemed to be a contributory factor to any subsequent problems.

Adhesives

Tackifier adhesives used for the installation of carpet tiles should be carefully applied from a tray using a roller and the penetration of the tackifier between the edges of the panels must be avoided to prevent adjacent panels bonding together.

The film of tackifier should then be allowed to dry before the floor finish is installed. This will ensure that excess moisture is not trapped beneath the floor finish and will also avoid the possibility of a permanent bond being obtained. Under no circumstances should the tackifier adhesive be poured directly onto the floor.

Pressure sensitive adhesives are used for the installation of PVC (vinyl) floor coverings. The preparation should be as above.

High temperature adhesives should be considered where higher surface temperatures may be expected, for example, conservatories, glass atriums, etc.

Summary

Where adequate corrosion protection is given to metal clad panel floors corrosion is not generally a problem. The solution therefore rests with the specifiers who, when specifying performance criteria, must insist that raised access panel floors have adequate protection.

Find more technical information about contract flooring in the CFA Guide to Contract Flooring.