Concrete and timber are the two materials most used for the construction of ground and upper floors, the choice of one over another determined largely by performance criteria. Ground floors will need to meet thermal performance requirements, and construction of upper floors will be influenced by the required sound and fire resistance and clear span. Ground and upper floors constructed of concrete or timber are described in this chapter.

4.1 Functional requirements

The functional requirements of a floor are:

  • Strength and stability
  • Resistance to weather and ground moisture
  • Durability and freedom from maintenance
  • Fire safety – resisting spread and passage of fire
  • Fire safety – providing stable support for occupants to evacuate
  • Resistance to the passage of heat
  • Resistance to the passage of sound


The strength of a floor depends on the characteristics of the materials used for the structure of the floor, such as timber, steel or concrete. The floor structure must be strong enough to safely support the dead load of the floor and its finishes, fixtures, partitions and services, and the anticipated imposed loads of the occupants and their movable furniture and equipment. BS 6399: Part 1 is the Code of Practice for dead and imposed loads for buildings. Where imposed loads are small, such as in single‐family domestic buildings of not more than three storeys height, it is common to construct a timber floor. The lightweight timber floor structure is adequate for the ...

Get Barry's Introduction to Construction of Buildings, 4th Edition now with O’Reilly online learning.

O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.