Protection against the spreading of fire
Raised flooring and hollow flooring offers the ability to place all the
building’s service systems, such as cabling, supply and disposal lines,
ventilation, heating, air-conditioning, etc. wherever they are needed.
Such facilities also have to satisfy certain requirements in the event of a
fire, having to allow for the following criteria:
- Protection of adjacent emergency rescue routes
- Protection of other neighboring units used
- Maintaining the stability of partition walls placed on the floor
- Fire-resistance period of the design
- Combustibility and building materials rating
- Protection against fire in the floor cavity
- Protection against fire in the room
Protection against fire in the cavity
The details are regulated in the December 1998 version of the “Sample
Guideline for Fireproofing-related Requirements on cavity type flooring
and raised flooring” (or: “MDBR”).
Even in the countries in which this guideline has not (yet) been introduced
into the building regulations, property developers can still make
use of it. In developing and adopting the Sample Guideline, there will
be the benefit that the representatives of the states’ building authorities
will identify with its content.
Fires cannot be ruled out as a result of operating cable and duct systems,
in instances, for example such as overheating. In such cases, the
construction has to resist this fire load. In actual practice, it must also
be noted that, with small cavities (< than 7.9” (20 cm)), due to the lack
of oxygen no blazing fires can develop, which has been accordingly
put into practice in the MDBR. In fire tests according to DIN 4102 and
DIN EN 13 66 Part 6, ETK-stressing and loading at 1.5 kN/m. is required
in Germany. For more details on this, refer to Specifications Sheet 11
of the BVS [National System Floors Association]. The MDBR is presently
being revised, the details not yet having been determined at the time
When studying the MDBR, it is advisable to pay attention primarily to
the text. Because most of the illustrated explanations refer to special
cases, relying only on these illustrations alone may cause misunderstandings.
In addition to this, one must also take into consideration the
concerns of spreading fires and of partitioning in fire compartments.