Both sides of the equation should be equal in order to end up with a stable and secure roof structure.
Loads on roof truss.
If the bottom chord of a roof truss functions as a floor joist such as in an attic room it carries a live load that also varies by use but a typical live floor load for a residential space is about 40 pounds per square foot.
Examples of live loads are snow wind rain and temporary construction loads.
Sure there may be an instance where stick framing is your only option and that is understandable.
Live loads are not always present.
The pros of using roof trusses instead of stick framing.
A judicious combination of the working loads keeping in view of the probability of a their acting together and b their disposition in relation to their loads and the severity of stresses or deformations caused by the combination of the various loads is necessary to ensure the required safety and economy in the design of a structure.
The pros of using roof trusses drastically outweigh the pros of stick framing.
Here are the pros of trusses.
Like all other design loads that apply to trusses snow loads are determined by the building designer and must be specified in the construction documents for use in the design of the building and the roof trusses.
But 99 of the time a roof truss is going to give you so much more.
But sometimes the loads that are specified don t provide enough information to ensure that the design will be correct for the specific circumstances.
Roof truss basics roof trusses are engineered wood alternatives to hand framed rafters.
Load combinations on roof trusses.
The formula for truss loads states that the number of truss members plus three must equal the twice the number of nodes.
The live loads a truss is required to bear are determined by local building codes.