Hip framing for barrel roof

[spockman]

I am designing a timber frame structure with Glulam trusses (100ft span, 20ft o.c.), glulam purlins and 2x rafters. The architects have now added hips at each end of of the roof. Does anyone have a recommendation on how to frame the hips?

 

[msquared48]

Is this a regular hip, where the hips are at 12:12, meeting at a point 50 feet in from the end, or a Dutch hip?

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[spockman]

It is a regular hip.

 

[ToadJones]

there are numerous ways to do it, but if it is open underneath the architect will likely have a preference

 

[focuseng]

Hip girder trusses off a main girder truss?

MAP

 

[hokie66]

I would put a truncated girder truss 30' from the eave, thus 20' from the peak. That way, you only have to connect one hip truss to the girder at a time. Connecting them all at a peak is a real pain.

 

[woodman88]

The nice thing about hokie66 idea of a 30' setback hip truss is that it will only have 25/20 higher stresses than the 20' oc truss.

Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.

 

[ToadJones]

The problem with the truncated hip girder trusses is all the messy framing it takes to complete the hip.

I'd still like to know if the framing is exposed underneath.

 

[spockman]

Yes, the framing is exposed from underneath. The bottom chord bracing will also be glulam and exposed.

 

[ToadJones]

well, then I doubt the architect is going to want to look at hundreds of hip roof truss framing members. The standard hip roof truss packages aren't very pretty.

You might consider stick framing the hips with large LVLs or glulams.

 

[spockman]

My current design shows glulam hip roof trusses framing into a girder truss at 8ft o.c with 2x sub-purlins. However, since the hip is on a barrel, and the ridge is curving and sloping it will mean that each truss will be different. I know this works, but it is also going to be expensive. I was hoping there was an easier way to do it.

 

[MiketheEngineer]

Obviously, you are going to a custom mfg for the Glu-lams. Ask them. While all the responses are great - the mfg will tell you how they want to do it - preferably economically!!

 

[hokie66]

"the hip is on a barrel, and the ridge is curving and sloping" tells it all. The architect is building a monument, and you can't expect it not to be expensive.

Is it possible to attach a framing plan? We might (or might not) have some useful suggestions.