Rafter Tie Spacing

luvflyin

Touchdown! Greaser!
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Luvflyin
Gonna build a house. Pretend it's a hangar so I can justify asking the question here. Cathedral ceiling. Don't want to have scissor trusses made because I want the pitch of the ceiling to be the same as the roof. I don't want to use a Ridge Beam. I'm going to use Rafter Ties on the Top Plate. Code says a Rafter Tie every 48". However, the exterior walls are going to be 2X6 with double Top Plate. If 48" between Rafter Ties are good for 2X4 exterior wall construction, then it seems that more space between would be fine for 2X6 construction. Anyone know of any reference that allows this.
 
I compared the cost for the additional materials to overbuild my garage/guest room in ways you mention, and the $ difference was not worth it to skimp.
Bonus? When the wind hits 60mph, I have no worries.
 
2x6 walls give you more room for insulation, and, yes, it won't flex quite as easy, but 30' of wall will still be plenty weeble wobbly. So, it won't make that much difference when it comes to resisting the outward forces from the rafters.

Snow load, baby, snow load.
 
I compared the cost for the additional materials to overbuild my garage/guest room in ways you mention, and the $ difference was not worth it to skimp.
Bonus? When the wind hits 60mph, I have no worries.

Yeah. It's about esthetics. But there's other ways to hold the roof down at every rafter. Just want to keep the cross ties to a minimum. All they're doing is keeping down pressure on the roof from spreading the walls apart.
 
2x6 walls give you more room for insulation, and, yes, it won't flex quite as easy, but 30' of wall will still be plenty weeble wobbly. So, it won't make that much difference when it comes to resisting the outward forces from the rafters.

Snow load, baby, snow load.

Yeah. Not really an issue here.
 
Rafter ties are about winds and uplift. Every other rafter is typical.
 
Rafter ties are about winds and uplift. Every other rafter is typical.

Yeah. There's metal things called rafter ties, often called hurricane ties, thats what they do and I'll have one at every rafter. What I'm referring to is what goes from outside wall to outside wall and keeps the down pressure on a sloped from pushing the walls out. They're called Rafter Ties in Building Code. Ceiling Joists usually do the same job. Sometimes Collar Ties do it.
 
What you're referring to would need to be engineered. Adding a ridge beam would be easier.
 
Gonna build a house. Pretend it's a hangar so I can justify asking the question here. Cathedral ceiling. Don't want to have scissor trusses made because I want the pitch of the ceiling to be the same as the roof. I don't want to use a Ridge Beam. I'm going to use Rafter Ties on the Top Plate. Code says a Rafter Tie every 48". However, the exterior walls are going to be 2X6 with double Top Plate. If 48" between Rafter Ties are good for 2X4 exterior wall construction, then it seems that more space between would be fine for 2X6 construction. Anyone know of any reference that allows this.
FWIW, here in Tennessee where we are rebuilding after the Nov 2016 Gatlinburg fire, we have exactly what you describe with 2x6 walls and cathedral ceiling. Our code mandates, and we are installing ties on 48 inch spacing. Our ties are going to be hand hewn rustic wood beams.
 
FWIW, here in Tennessee where we are rebuilding after the Nov 2016 Gatlinburg fire, we have exactly what you describe with 2x6 walls and cathedral ceiling. Our code mandates, and we are installing ties on 48 inch spacing. Our ties are going to be hand hewn rustic wood beams.

I've been on another bulders forum. It looks like 48" is the law. It's about the amount of work each tie, particularly it's attachment point has to do. The extra resistance to 'bowing out' that the 6" plates give over 4" is not a factor. It would be to 'busy' looking in my project to have that many. It's a small space. I'll have to come up with something different. Probably scissor trusses and live with shallower slope inside. Have fun with your project.
 
Have you by chance looked at insulated concrete form (ICF) construction? Built ours that way several years back, and love it. When the storms come, 6" concrete walls are a bonus, and SUPER insulated!!....total electric home and I complain if the power bill goes over $100 for the month. Plus, we can't hear jets departing on the runway 600 feet away.

Jim
 
A cousin who is structural engineer did the "impossible" for his own house. Cathedral octagon, with no visible collar ties.
While it's a standard wood-framed house, this area required structural steel welded in place to accomplish the desired look.

I used to do some remodels, and was often asked: "Is it possible to...?"
My standard answer: "Anything is possible. how big is your checkbook?"

The county will require engineering. May as well consult one now, rather than ask random pilots on the internet.
 
A cousin who is structural engineer did the "impossible" for his own house. Cathedral octagon, with no visible collar ties.
While it's a standard wood-framed house, this area required structural steel welded in place to accomplish the desired look.

I used to do some remodels, and was often asked: "Is it possible to...?"
My standard answer: "Anything is possible. how big is your checkbook?"

The county will require engineering. May as well consult one now, rather than ask random pilots on the internet.

I can see how that would work. Eight runs of top plate, non of them real long themselves. It probably wouldn't take a huge amount of steel to do the job. I'm curious to know how long each of the eight legs was. There is going to be an Engineer used to finalize the plans and put his stamp on them. I'm just doing some homework hoping to find a paragraph from Building Code to quote. I haven't met the guy yet and don't know how experienced he is. Just hoping to keep his hours down. Don't want him spending time 'calculating' if calculating isn't needed. I'm looking elsewhere for answers, not just here. I've seen a lot of experience, and questions answered here on POA on a lot of subjects.
 
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