Part B

Fire protection within a building can be categorised into two different types:

Active fire protection

Detection and suppression

Fire and smoke detectors, alarms

sprinklers and fire extinguishers

Passive fire protection

Materials, construction and building design

Used to prevent fires developing and the passage of flames and smoke from one area of a building to another.

Maintain the building structure to allow escape and fire fighting

Protect life, the building, it’s assets and business activities

Approved document B

Gives guidance on meeting the requirements of the Building Regulations, they

  • Are only concerned with life safety, not the protection of the building or it’s contents.
  • Classify the use of a building into purpose groups and specify minimum periods of fire resistance to be achieved.  These will be between 30 minutes and 120 minutes, the exact time period will be dependant on the type of building, the height and if there are sprinklers fitted.
  • Are applicable to all types of building including: Residential, Healthcare, Education and Offices.
  • Control the materials used to form the internal surfaces of the building to reduce the risk of fire growth and internal fire spread.
  • Due to changes in the method of measuring the temperature within a furnace, the test has become more severe especially during the first thirty minutes of a test.

The Building Regulations, have adopted the new test method but the periods of fire resistance have remained constant. In effect the level of fire safety has been raised in the UK.

A change to the Building Regulations means companies can trade on tests conducted to either EN or BS

British Gypsum has retested the bulk of its systems range and the 2005 edition of the White Book will show tables to both EN and BS.

In addition to the severity of the new EN fire resistance tests, the test standard also imposes strict rules governing the use of tests to cover specific end use scenarios (field of application).

One of these rules applies to the maximum partition height that can be claimed for a partition.

BS 476 ignored the effect of height on the performance of a partition, so a system tested at 3m could be built to 20m with no difference in claimed fire performance.

EN standards do not allow this and the maximum partition height is now determined by one of four methods

1. Test at 3m and claim a maximum height of 3m.

2. Test at 3m and providing partition does not deflect more than 100mm claim up to 4m.

3. Test at 3m and carry out assessment to determine maximum height

3. Test at the design height.

An extensive series of tests on partitions with heights up to 6m has been conducted to provide data for the new White Book performance tables.

This change in the method of assessing maximum heights means that the same partition may have different quoted heights at different fire resistance durations.