ABSTRACT
Forming part of the building envelope, roofs are one the key construction elements and have formed the basic provision of shelter since the beginning of human existence. While this may be considered a profound statement, it is important and relevant to consider the following performance criteria for roofs:
When inspecting and analysing any roof it is essential to consider the performance criteria in the context of the type of roof and also the materials used. Throughout the passage of time there has been an evolution in roof design and the specification of materials used to execute this. However, the concept of the roof has remained largely unchanged for thousands of years. In essence, roofs fall into one of two categories:
These principal differences between the roof types will be analysed in more detail later in this chapter but it is also important to consider the variation in the application of roof design within the commercial buildings sectors. Not only is it important to understand the principal difference between pitched and flat roofs but also the relevance of building age; this, along with the relevant construction technology, is vital when advising an owner, occupier or investor.
