Vaulted Ceiling/no Ceiling Joists

medusa

Ok, I'm stuck with a house that had a 24' x 24' vaulted living room added, with no ceiling joists, there is (built on site) scissors truss used at 24" O.C., but, as California is earthquake country, anyone have suggestions on what/how to use-cable/threaded rod with turnbuckles/wrought iron to hold the outer walls together?
I know I'll have to get an Engineer to do the calculations, but just looking for suggestions, past experience, photos, etc. of similar situations.

nailbanger138

I have never used the turnbuckle method, but have done cut roofs like this in CA. Typically a ridge beam is sized by an engineer to carry the roof load. The rafters are "scissorred" over the top of this beam. This creates a sot of collar tie. The rafters can be seat cut on the top but dont have to be. Instead of running the rafters directly opposite each othe the run beside each other for through nailing over the beam. In this scenario, the walls cant pull apart unless the ridge beam is allowed to sag. The engineer obviously takes this into account in beam sizing. I hope this helps but it sounds like you are trying to fix what is already there.

medusa

Thanks for the response, and yes, I am trying to fx what is already there., so I think the threaded rod/turnbuckle or cable fix will be the bext way to go.
The ridge is 24' long, so it would take a heck of a beam to be installed, it is an option, though.
Funny, did an exaustive shearch on the internet for information on turnbuckle/rod and or cable ceiling joists, can't seem to find much of anything.

locofoco

Here's an idea. How about using 3/4" or 1" allthread encased in some decorative (hollow) beams. Would it be possible to tighten nuts down at the end(s) in lieu of turnbuckles? The rod,once tightened, would carry the span of wood beam. Fastenal should have the rod and turnbuckles.
This is just an idea, I'm not a P.E.
Loco

Tom R

This is the way I'd probably be leaning, too, - - but it depends what 'final look' you're out to achieve.

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medusa

locofoco ,
thanks, great idea, could use copper/brass pipe to hide the all-thread, let it age normally, or paint it. Simple/straight forward/inexpensive.
Tom R,
thanks for your input, the look I am working toward is as unobtrusive as possible, the vaulted ceiling with two ceiling fans looks great for the room right now, just having 1" +/- rods every 4' O.C would not change the look of the room much.

If I had the money to spend, a wrought iron designed traingle woudl look great.

Looking for an Engineer to get his stamp on sizing/grade of "rods".

Tom R

A 'natural-chain' look would be different, - - bold, yet unobtrusive, - - and you won't see 'that' at the Jones's house!!

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Nick H

If you are looking to span 24' I think you will need a vertical rod to support the middle to stop it sagging. Ive seen fairly decorative iron fittings used where these two rods would meet/join.

reveivl

What's the actual problem here? Is the structure failing now? Or are you simply concerned that it might fail? Maybe the scissor trusses are well built and appropriate to the span/load. It seems a shame to put bars across the ceiling if not totally nec. Get your eng. to look at the existing before fixing. Just a thought...

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