 RAISED FLOORING SPECIFICATION
|
| |
The quality and performance characteristics of manufacturer’s products vary considerably. Key performance criteria are stipulated for the component parts of a system and generally Contract Administrators or end users will confirm their performance requirements in-line with one of the following specifications:- |
| |
- National Building Specification Ltd October 1991 Standard Version K41
- PSA MOB PF2 PS/SPU
- BSEN12825 European standard
|
| BSEN 12825 AND PSA/MOB PF2 PS SPU – WHAT ARE THE MAIN DIFFERENCES? |
| |
There is no British Standard for raised access floors but the PSA Method of Building performance specification “Platform floors (Raised Access Floors)” MOB PF2 PS is the de facto industry standard. The K41 specification is dominant and refers to the PSA MOB PF2 PS/SPU as a specific reference document used in its drafting. The two documents are therefore intrinsically linked in most specifications. |
| |
BS EN 12825 was formally adopted in August 2001 under the European Harmonisation Programme as a means of providing equal opportunities of tendering and trading in the UK for European manufacturers of raised access floor products. |
| |
At this point we would confirm that contrary to the assertions of certain manufacturers, the PSA MOB PF2 PS/SPU has NOT been superseded by the European BSEN12825 specification; it is simply another specification route albeit subject to less stringent rules. |
| |
Systems which are compliant with PSA MOB PF2 PS/SPU are subject to independent testing criteria and performance standards. In general these standards are far more stringent than those governing the new European standard BSEN12825. |
| |
Floors installed to PSA MOB PF2 PS/SPU have a 3 times safety factor whilst those installed to BS EN 12825 have only 2. |
| |
The table below gives loadings for the 4 main grades of PSA MOB PF2 PS/SPU floors. |
| |
- Light grade flooring is for office environments with any heavy cabinets or furniture.
- Medium grade flooring is for general office accommodation where heavy office equipment, archive cabinets, fire safes and heavy concentrated areas of desks will be in used.
- Heavy grade flooring for computer rooms, telephone exchanges, public areas, control rooms.
- Extra Heavy Grade flooring for computer rooms with heavy equipment, plant rooms and other special equipment.
|
Grade |
Concentrated load over 25mm sq. |
Concentrated load over 300mm sq. |
Uniformly distributed load |
Light |
1.50 kN |
2.70 kN |
6.70 kN |
Medium |
3.00 kN |
4.50 kN |
8.00 kN |
Heavy |
4.50 kN |
N/A |
12.00 kN |
Extra Heavy* |
4.50 kN |
N/A |
12.00 kN |
|
| |
* In addition extra heavy must be capable of sustaining a total load of 11Kn applied equally on four points of 25mm square on a 200mm square grid anywhere on the panel. |
| |
Installed systems shall withstand the 3 times the individual loads (a 3 times safety factor) for 5 minutes without collapse. The exception to this is the 11 kN load applied to the Extra Heavy grade which must withstand only 2 times the load for 5 minutes. |
| |
Designers should be aware that they are specifying the correct type and strength of floor for the end users purpose. For example, a Medium Grade panel system (pedestals included and based on a point load of 3kN) is defined as suitable for general office accommodation. BS EN 12825 has no such guidance! |
| |
It’s not just panels that need to be considered, the pedestals supporting the floor are key to providing a floor that is right for its intended use. |
| |
With BS EN 12825 it only provides for pedestals to be tested by applying a vertical load of four times the working load directly to the centre of the pedestal. There is no requirement to indicate the height of the pedestal during the test procedure – i.e. the height tested may not be the same as that required by your project! |
| |
PSA/MOB PF2 PS SPU requirements are much more stringent. Tests provide for vertical load tests on the centre and quadrant positions of the pedestal head. In addition horizontal loading is applied to the top of the pedestal to measure the restriction in free play of the pedestal. The proposed pedestal is tested at a minimum specified pedestal height. (invariably far higher than your project requirement!) |
| SO, WHAT SHOULD YOU DO NOW? |
| |
Be careful! Nothing is left to chance with the PSA/MOB specification route, there being a requirement to provide a system fit for the purposes intended, of sufficient life cycle span and underpinned by the manufacturers and installers insurances. |
| |
The PSA/MOB Independent Testing and Certification has over many years given the specifier/designer, the builder, the client and the insurers for all three, the assurance that the four grades within its specification are all independently tested and certificated, and includes the method of constructing the raised floor on site and the understructure used (which BS EN 12825 does not) and as a result ends up with full warrantee/guarantee of 25 years for the panels, 50 years for the understructure and 25years for the full system. |
| |
BS EN 12825 carries no such mandatory warranty or guarantee, so each individual manufacturer/installer produces product, tested “in house”, which they consider fit for purpose and they may or may not offer a warrantee. Once again care must be taken by the specifier/buyer in assessing exactly what type of written warrantee is being offered. |
| |
- Check whether the manufacturer is prepared to provide a written warranty for the products offered inclusive of understructure (warranty’s can be compromised if a mixture of manufacturers products are used).
- Check whether the advice you have been given by the prospective installer is underpinned with Professional Indemnity Insurance
|
| |
|
| IF YOU WOULD LIKE ANY FURTHER INFORMATION ON THE ABOVE OR WOULD LIKE TO FIND OUT MORE ABOUT THE PRODUCTS OR SERVICES WE OFFER PLEASE CLICK THE CONTACT US BUTTON AND OUR STAFF WILL BE HAPPY TO HELP. |
| |
|
