The roof is one of the most important parts of a building. In
Thailand, there are currently many different types of roof sheets,
made from various materials, which users can select according to
their price and usability. At present, 60 percent of low- to
moderate-income consumers use cement roof sheets, and of them
75 percent select asbestos cement roof sheets [29] as the price of
an asbestos cement roof sheet is only 5 to 6 US Dollars per square
meter [10] – an acceptable price for low- to moderate-income
people in Thailand. In addition, these asbestos cement roof sheets
provide good thermal properties and adequate fire durability,
strength and flexibility. However, this type of roof sheet also
contains toxic substances that enter the body through the respiratory
system and can cause conditions such as Asbestosis, chronic
lung disease, malignant pleural disease, tumors, and cancer of
the lung and other parts of the body [30]. Alternatively, there are
other types of roof sheet which are safer to human health, such
as concrete roof sheets, ceramic roof tiles and fiber cement roof
sheets with a range of prices and physical properties.