In parallel with the famous annually International Conference Series TUSNAD, organised on the topic of built heritage rehabilitation, starting from 1997, a series on historic structures began to offer to specialists an opportunity to discuss major aspects regarding the resistance and the stability of historic buildings.

The protection and transmission of the authentic historical message must be made through the resistance structures also, this including modesty and respect from every person or specialist, towards human creations reflected by ensembles, materials, details and structural technologies. The volume from 1999 includes the lectures given during the 3^rd edition of the International Conference on Historic Structures, on the topic Historic Roof Structures.