1 1/2 story cottage wall plan ?

[schiada]

Hello John.
Been out with a shoulder problem ,but getting back at it.

Could I use a 12'- 6" x 10" instead of the 10' - 6" x 10" for the wall studs ? Saying I leave every thing else the same ? Would like to add the height to the upper floor. Think its like 1' now, and would  become 3'. Could the wall take it ? Here is the idea with a dormer added.

If the walls can talk it I will need to have some engineered truss made for the roof at the dormer.



Thanks for the input. Randy

[John Raabe]

The limit of the 10' studs in the stock plan was for an open cathedral space where a wall taller than 10' will require ties to keep the two sides from spreading.

If you will have a full length loft floor, and a truss system for the roof, then you do not need to use a balloon framing system at all and can do platform framing with the knee wall built on top of the loft platform. The roof trusses above with resolve the outward forces and keep the roof from pushing outward on the wall. I expect a 4' or 5' high knee wall will give both more usable loft space and be an easier truss design for the truss company.

[schiada]

Thanks John ! Yes I need to keep the  cathedral .

On sheet 0/3 , Loft Framing, the ties at #3,#6,#9 #12 are not enough  for the 2' extra on the wall studs ? I know not to use the "E" word. Could the ties  at #3,#6,#9,#12 be pulled up to the point where the roof truss would meet the 12' wall ? What about 2 x 8 wall also ?

Sorry for being a pain !

Thanks, Randy

[John Raabe]

If you are using commercial trusses along with their metal connectors then you are not putting outward forces on the tall walls in the cathedral section of the house. The question then becomes is that 12' high wall stable with its own ability to stand up to wind and other sidewards forces. The 10' limit of the prescriptive unbraced wall height goes back to the days of 2x4 framing as was not updated for 2x6. A 2x6 framed wall with structural sheathing well nailed will be much stiffer than the prescriptive wall, I think most people would agree. Is that enough? Such an engineering problem would involve calculating things like exposure at the site to strong winds.

If you want to make your own decision, there are things that could be done to make that wall stiffer such as an interior sheathing of plywood or foundation straps running from the foundation and nailed over the wall sheathing and into wall studs. Those might be what a prudent builder would do.

But we can't give you engineering advice.

[schiada]

Thanks a bunch John !

So having the tall wall system engineered is the way to go.

Randy

[John Raabe]

Yes. That would be the best way to check it.