Roof rafter design
Roof rafter design
(OP)
In designing the roof rafters, the California Building Codes requires (using allowable/working stress design) the 8 load combinations. Usually we use the DL+LL. To include the wind load (DL+0.75LL+wind), does it apply vertical to the rafter? Is there any design example showing the design criteria.
DL+LL
DL+.75LL+wind
DL+LL
DL+.75LL+wind





RE: Roof rafter design
RE: Roof rafter design
Mike McCann
MMC Engineering
RE: Roof rafter design
RE: Roof rafter design
The MWFRS wind is for the overall building design (i.e. lateral force brace systems) and would not be used for a single rafter.
RE: Roof rafter design
DL+0.75LL+Wind = 12+.75*12+12 = 33.
RE: Roof rafter design
Do you know of a design example showing the roof wood rafter design for DL+LL+WIND using the California Building Codes 2013 (using allowable/working stress design)? Does the above total load of 33 lb/sq ft load is reasonable or over killed?
Thanks