These recommendations have been prepared by a Working Party of the Commission on Practical Construction. 

The bulk of experience in flat slab design and construction has been made in the USA and Australia. It was therefore only logica! to base these recommendations partly on the respective standards of these countries. 

On the other hand, CEB and FIP have jointly produced the Model Code for Concrete Structures and its design principles were followed as much as possible. 

Research works conducted in the USA, Australia, Switzerland and in the Netherlands have contributed to an improved understanding on the behaviour of both reinforced and prestressed concrete flat slabs and this information was also considered. 

The recommendations deal with the use of bonded or of unbonded tendons. In some chapters special emphasis has been given to the application of unbonded tendons, as the. Working Party feit that flat slabs with bonded tendons can be designed and constructed following established standards available in most countries. The Working Party is convinced that, if properly designed and detailed, both methods have their merits. 

The document was approved by the Working Party and then circulated for final comment among FIP Member Groups in 1979. Valuable contributions were received from the CSSR, Denmark, the Federal Republic of Germany, Japan, the Netherlands, Norway, South Africa, the USA and the USSR, and were incorporated where possible. 

It is the hope of the Working Party that this document will be favourably received by consultants, contractors and authorities and that it will assist in widening the safe, functional and economie use of the method. The Commission wishes to express its thanks for the work done by the members of the drafting group listed below.