roof rafters - no ceiling

[jonathanwilkins]

I'm working on a framing plan for a customer - the house has a very large 12/12 pitch roof and much of the 2nd floor is located inside of it. The living room of the house, on the plans, shows a vault from the exterior walls going flat at the same height as the 2nd floor ceiling. The longest rafter span (to a king rafter) is ~21'. There is also no way to support the ridge as it is over the living room.

End result is I can't use an i-joist rafter because there is no where to support a structural ridge, conventional framing doesn't even come close to working b/c the lack of ceiling makes the rafters way out of span. I thought about designing the top plate as a beam but can't get it connected at the ends.

Any ideas?

 

[Stillerz]

Man, someone had a bad meeting with an Architect recently!!! (by the way, at our office we call them "A's"..can't even say the full word).
I've never seen someone get so pissy about a little misnomer.
Do you also get pissed when someone says "footer" instead of "footing"?

 

[msquared48]

If this is common and accepted terminology in AU, the UK or other countriues, my appologies.

My point was not made in anger. If you construed that, you're wrong. I am a stickler though on using proper English as well as proper technical terminology for what I perceive is my profession. It was merely meant to educate. Take it as you will. No worries, and no offense intended.

Mike McCann
MMC Engineering

 

[paddingtongreen]

Not an accepted term in the UK, or not before I came here.

Apsix, I must have been stuck in Mid-Atlantic, I intended to write, "Sheeting Rails".

I thought we were just passing time, waiting for a sketch of the problem, especially with all of this ambiguous terminology floating around.

Michael.
Timing has a lot to do with the outcome of a rain dance.

 

[BAretired]

Quoting a portion of the definition from the glossary of building terms which Mike introduced,

One of a series of structural members of a roof designed to support roof loads. The rafters of a flat roof are sometimes called roof joists.

Personally I would not call a roof joist on a flat roof a rafter. I would call it a joist, but if it can be called a rafter, then maybe floor joists can be called floor rafters.

Just kidding! I really don't find the term "roof rafter" to be all than offensive.

BA

 

[jonathanwilkins]

Sorry I haven't posted a sketch, the roof is a hip roof...there is no gable end to post a ridge beam. That would be too easy. The main ridge terminates at a point over the vault...no where to post down.

I wound up not doing anything. The contractor is in an area where engineers aren't required & he "can make it work." Just thought an engineer could help him. I'm interested to see if I hear back from him.

Thanks for all the replies.

 

[BAretired]

Post a sketch! We are not mind readers! You are not fulfilling your obligation, namely to clarify the problem so that we have a clear understanding of it. We need your input in order to provide intelligent responses. Otherwise, this whole thread will have been a waste of time. Move it!!!!!

BA

 

[apsix]

Use a steel cranked ridge beam.
And, post a sketch.