huangyhg

light wood roof trusses
we are planning a frame building 61 ft x 66 ft using light wood trusses .... cottage roof ..4/12 pitch. anyone know of some sketches on the net for ideas on on appropriate location of girder trusses. we need to identify point loads for foundation design.
if you are dealing with a hip roof, anywhere from 8 feet in for residential, to 16 feet in for commercial and longer spans, depending on how it affects the economy of the truss design.
if you are dealing with a dutch hip, then the girder truss is at the face of the dutch hip.
if you know the truss company to be used, they should not only be abletter idea than e to give you a better idea than i, they should be able to provide you with a layout and the reactions.
mike mccann
mmc engineering
the girder setback will likely be 8' +/- a couple of inches.
if you need to get started, just specify an approximate girder setback in your plans. certain suppliers like certain dimensions (my old company used 7'10 1/2") in order to make the drywall work out evenly. it's not set in stone.
alternatley, you could just design your footing for 12-18" of load eccentricity and give your truss supplier a 2' window to work with. this would cost you next to nothing as far as the footing goes.
assuming a hip roof you would probably be safe with an 8' setback, but without seeing the plans or knowing the loading it is only a guess. if you increase the setback to 10'-16', truss reactions can get very large, not to mention truss to truss hanger costs.

component runner, llcfff"> is a design outsourcing company that specializes in wall panel and truss design services using mitek software. if you would like to learn more, check out our website.
we can run some preliminary designs with girder locations and reactions if you provide the roof loading and location of the building.
chip dean
this varies from truss company to truss company. we always used 10 foot setback unless it was a dutch hip.
we always set the girder truss dimension and expect them to adhere to it. no problems.
consider this design link:

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