Extending existing studs

[Localeng]

Existing house has top plates at 8'-0" high, but the owner wants to raise to 13'-0".
I'm thinking of two ways of extending the studs.
First way is to install 5'-0" new studs on top of existing top plates and Simpson straps on both sides of studs from new studs to old studs passing top plates. Minimum 30" strap, so minimum 12" on both old and new studs.
Second way is to install sister studs in full height, 13'-0" at each existing studs. This requires much more demolition.
First way is preferable if Building codes allow.

So, does anyone know the first way is code compliant?
If you know other ways of extending the studs, could you share with me?
Thank you in advance.

 

[XR250]

Straps are unlikely to be a viable option. The bearing part of the system will never likely stay tight enough to prevent unwanted hinging or looseness in the wall. ....and the studs end up being to tall to be code compliant (at least in the US)
If it is a 2x4 wall, sisters won't work either unless you use 2x6's. I do this a lot when a customer wants to vault a ceiling and the gable end needs reinforcing.

 

[jayrod12]

We have successfully in the past used steel wind posts that go from floor to underside of roof sheathing, and then used the existing double top plate as a wind beam between these posts. If allows for less cutting and installing. This fix came up the first time for me when some builder constructed a gable end wall in a vaulted ceiling application with standard 8ft studs to match the sidewalls. That wall bounced in and out like a trampoline when you leaned against it.

 

[KootK]

I've done the same thing as Jayrod but with wood stud packs spaced every 6' or whatever. It's a good compromise between constructabilty and half ways respectable engineering. The viability of this will somewhat depend on the nature of your walls though. If you've got some nice, straight runs, this works great. If you've got a jog or a window every 2', not so much.

I agree with XR that the steel strap solution is questionable. Given the realities of fastener slip and the straps straddling soft plate material, that makes for a pretty sketchy moment connection in my opinion. I'll do it for low importance, low axial situations sometimes. Guard wall bases or maybe gable end walls. It strikes me as too prone to p-delta effects for anything with real axial load though.

HELP! I'd like your help with a thread that I was forced to move to the business issues section where it will surely be seen by next to nobody that matters to me:

http://www.eng-tips.com/viewthread.cfm?qid=456235