1. Load standard value of the standard value of the value of the source there are two, one is based on the national norms of the building structural loading specification GB 50009-2012 "chapter 4 of the floor and the roof are not Live load of this chapter of industrial and civil buildings have made detailed provisions for the load value. Another is the local standards, such as Harbin, the provisions of the roof live load than the national provisions of the roof load value is much larger, usually the design institute is against the national standards and local standards, the district large value. (Of course, local standards tend to be more conservative, take the value is larger than the national standard).