Load types loads used in design load equations are given letters by type.
Water roof live load.
Used but they typically defined the load cases or combination stress or strength limits and deflection limits.
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.
In my region on cape cod we have a ground snow load design of 25 psf which is a greater design load than the live load 12 psf to 20 psf over an entire roof system.
The load cases b to d are for sloping roofs.
In other words on a steep roof less material would be stacked in a concentrated area at one time to avoid having it slide off.
Load cases for rigid supported beams the centre to centre distance of the beams is a the bending stiffness is ei and the water level over the not deformed roof at the roof edge dhw.
D dead load l live load l r live roof load w wind load s snow load e earthquake load r rainwater load or ice water load.
However if the attic is intended for storage the attic live load or some portion should also be considered for the design of.
3 1 uniformly distributed load load case a.
2attic loads may be included in the floor live load but a 10 psf attic load is typically used only to size ceiling joists adequately for access purposes.
Roof assemblies are engineered to withstand serious structural failure due to overloading that is an excessive live load due to the build up of rain water or snow ice as predicted from the geographical climate zone.
Asce guidelines prescribe live loads according to categories of intended occupancy and use per building type.
Roof live loads largest roof loads typically caused by repair and maintenance pitch rise span lr 20 r1r2 12 lr 20 lr horizontal projection roof live load 16 r 1 r 2 live load reduction factors r 1 accounts for size of tributary area of roof column a t r 2 effect of the roof rise.
Very slightly over time.
The might of the dead load or lack thereof often defines how much live load it can handle.
Live loads roof live loads snow loads rain loads wind loads and earthquake loads are all examples of variable loads.
Load case a is for a horizontal roof.
And from overbearing for example when the pressure differential from excessive winds exceed the resistance of the roof.
