The parapet is a low wall around the roof of the steel structure building, the main role in addition to maintaining safety, but also at the bottom of the application of waterproof pressure brick to close the head, in order to avoid the waterproof layer of water seepage, or roof rainwater diffusion.
According to the national building code, the height of the parapet of the upper roof shall not be less than 1.1m, the highest shall not be greater than 1.5m.
The role of the parapet on the roof is to protect the safety of people and to play a decorative role on the building facade. People do not ascend to the roof of the role of the parapet in addition to façade decoration, but also fixed linoleum.
When there is a concrete pressure roof, the top of the floor slab is counted to the bottom of the pressure roof; when there is no concrete pressure roof, the top of the floor slab is counted to the top of the parapet.
The main role of the parapet in the steel structure building, is to do a good job of waterproofing the head, which is often referred to as the parapet flooding. General roofing, slope, insulation, waterproofing, etc. about 250mm thick, and then consider the end of the waterproofing layer rolled up 250mm high, parapet a total of 500mm high (twenty-first century practices generally 600, 700mm high).
Specifications, this height in different places have different requirements, generally limits the height; after all, this is a non-structural element, in the earthquake is also unsafe factor.
As for other height statements, such as: not less than 1200mm, are the parapet as a safety protection consideration, is a deviation from the original intention of the practice. To consider the safety, completely in the 600 high parapet and then do 600 high railings as protection.
Increasing the height of the parapet out of thin air, not only increases the cost, but also poses a security risk. Roof to do light protection measures better.