Hip Beam to Tension Ring Connection on Stick Frame Pyramid Roof

[Brick Jagger]

Hi y'all,

I have a 24'x24' stick frame pyramid roof with vaulted ceilings on an exterior ramada. There are no collar ties, so I plan to take the thrust out with a tension ring. I have scoured the existing threads on here about the design of this type of roof using diagonal hip beams and a tension ring at the plate. Those threads are very informative and I learned a lot, but now I'm trying to detail the hip beam to tension ring at the corners and I would like some help or direction.

The detail needs to restrain the hip beam and transfer its thrust into the tension ring All I can come up with is using screws to connect the hip to plate and a strap around the corner to tie the tension ring together. See the attached sketch. Has anyone detailed this before and can provide suggestions? Thanks!

 

[XR250]

I'd be surprised it you could get a screwed connection to work on a roof of that scale.
I usually end up doing a kinked flitch beam to support the peak in lieu of the tension ring strategy

 

[Brick Jagger]

Yeah I was having trouble finding strong enough screws for the thrust, which is somewhere in the 6-7 k range. Not to mention I'm not sure how to think about the load applied to the screws in that application. They seem like they would be simultaneously loaded in shear and tension.

I saw your previous posts about the flitch beam. So in that case, all thrust is taken out of the equation by the kink beam itself?

 

[KootK]

Yes... tension rings are all fun and games right up until it's time to sort the details.

You might be able to swing something with steel posts if that would pallatable.

 

[Brick Jagger]

Unfortunately structural steel is not an option, but what is interesting about this project is the architect wants 2'x2' masonry columns. So I was also considering something like attaching the hip beam to the top of column in such a way to resist the thrust and strapping the tension ring beams to the column. Not sure if straps from wood to masonry columns are an option though...

 

[XR250]

With 24x24 columns, you may not need a tension ring. Probably easy enough to embed a large flag plate in the masonry to make a decent rafter connection.

 

[Eng16080]

No chance a screwed connection like you show will work. Definitely needs to be something more like what kootk drew above.

This is what I came up with for a recent project. Obviously this is a little different than yours because I had a steel frame below the wood framed roof, but I would expect a similar type of connection to the hip. This connection used (4) 1/2" bolts. This roof was also only 13'x17', so I expect your connection may be more substantial.

 

[XR250]

I saw your previous posts about the flitch beam. So in that case, all thrust is taken out of the equation by the kink beam itself?

Yes but for something of this scale you are probably looking more of a kinked I-beam.