What is roof live load reduction?
What is roof live load reduction?
The commentary in ASCE 7-05 C4 about roof live load reductions explains the anticipated difference in use of roof areas vs. floor areas. The reduction formula has two reduction terms: One for the tributary area supported by the structural element (R1) and the other for the slope of the roof surface (R2).
Is roof live load reducible?
Live loads of 100 psf (4.79 kN/m2) or more at areas of roofs classified as Group A occupancies shall not be reduced.
When should I use live load reduction?
This means that if the column under consideration has only 1 slab above then no live load reduction is applicable. If there are 2 floors/slabs above then 10% LL can be reduced in the column in the lower level. If there are more than 10 floors above then 50% of Live load can be reduced.
What is Live load on roof?
Live Loads The weight of temporary objects on the roof is referred to as the live load. Live loads include the roofing crew and the equipment and tools they bring with them. A roof must be able to support both its dead load and live load at any given time.
What are examples of live loads?
Typical live loads may include; people, the action of wind on an elevation, furniture, vehicles, the weight of the books in a library and so on. A live load can be expressed either as a uniformly distributed load (UDL) or as one acting on a concentrated area (point load).
How much weight can a residential roof hold?
California building code sets minimum standards for roof load-bearing capacity. At minimum, any roof which may be used by maintenance workers must hold 300 pounds concentrated. Concentrated means that this weight can be held by any one spot on the roof.
What is a typical roof load?
The dead load of a typical asphalt-shingled, wood-framed roof is about 15 pounds per square foot. The load increases with the use of heavier roofing material. A clay-tiled roof may have a dead load of as much as 27 psf.
What is live load reduction?
Live load reduction is a reduction in live load that contributes to the actions on a member. If the roof design load is 20psf and you are considering the compression in a web member that is located near the mid-span than I would not use live load reduction for the compression in that member.
What is a roof live load?
The live load on a roof is the weight of any temporary objects on the roof. Where snow isn’t a problem, the live load can come from people working on the roof and any equipment they take on to the roof with them.
What is a construction live load?
What is Live Load. Definition of Live Load in Construction. The live load on a structure is any loading that is not always consistently exerted on the structure.
