couple of framing/bracing questions

[ugabulldog]

Hope the framing details in pictures are ok, this is a shop I am building.....First, do I need diagonal bracing for the roof (once temporary braces in loft are removed) Second, do I need brace for front wall (osb spans the two walls over top plates)

Lastly, I plan on nailing hurricane ties to rafters at top plate, do I need to put on rafters that tie into ceiling joists also?

I am in GA., Thanks

[Don_P]

If the metal is structural roofing and screwed according to manufacturer's directions then it provides bracing. It never hurts to have a couple of diagonals though.

The front wall is incorrectly framed, there is a hinge across the middle of the wall. It would correctly be balloon framed or have a floor reinforcing that hinge. We recently had a discussion on this in another thread.

the ties across the greatroom ceiling should not be removed unless there is a beam at the ridge (not a ridgeboard, an engineered beam). Otherwise they can be raised up to 1/3 of roof height and are required on every rafter set unless engineered. You'll have to check the rafter tables to see how much you can raise them for that size rafter. The collar ties in the upper third of roof height are required every 4' or closer.

There should also be blocking supporting all osb sheathing edges, a row of blocking covering all those seams that I'm seeing leaking daylight. It can be 2x4 scrap nailed in flatways to the studs and then 2 nails from the osb into the blocking on each side of the joint.

[ugabulldog]

If the metal is structural roofing and screwed according to manufacturer's directions then it provides bracing. It never hurts to have a couple of diagonals though.

The front wall is incorrectly framed, there is a hinge across the middle of the wall. It would correctly be balloon framed or have a floor reinforcing that hinge. We recently had a discussion on this in another thread.

the ties across the greatroom ceiling should not be removed unless there is a beam at the ridge (not a ridgeboard, an engineered beam). Otherwise they can be raised up to 1/3 of roof height and are required on every rafter set unless engineered. You'll have to check the rafter tables to see how much you can raise them for that size rafter. The collar ties in the upper third of roof height are required every 4' or closer.

There should also be blocking supporting all osb sheathing edges, a row of blocking covering all those seams that I'm seeing leaking daylight. It can be 2x4 scrap nailed in flatways to the studs and then 2 nails from the osb into the blocking on each side of the joint.

Thanks Don,...I will notch the top plates on each side of door header and nail a 2x4 to existing studs from slab to roof. ...And I don't plan on removing rafter ties, but they are only required every 4' according to the '03 IRC unless the newer versions have changed.

[Don_P]

I'm not certain which edition changed, the 4' clause is in my 2000 edition under R802.3.1, last sentence. It is no longer there in my '06. If it is there in the '03 then the change occured with the 06 version, not sure which version GA is under. Basically the math for the connections in the heeljoint table doesn't work at 4' on center, the nails are overstressed... connect it about twice as well as they call for. As far as I'm concerned most ridgeboards under most conditions are plenty adequate to act as a ridgebeam between ties 4' or even more apart as long as the tie connections are adequate. But they don't call it the rules according to Don  .

[MountainDon]

GA:  2012 statewide

http://www.iccsafe.org/gr/Documents/stateadoptions.pdf

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IRC from ICC:

http://publicecodes.cyberregs.com/icod/irc/2012/index.htm