Height to width ratio for sound structure?

[Jim Timber]

I'm in the design phase of what will be a utility shed on the main floor, and a bunk house/ lounge on the second story.

I'm thinking 16' wide would be nice, but only want to make it 20' long. I want a full 8-9' ceiling on the ground level, and at least a 7' ceiling upstairs. I'll probably be using dimensional lumber for the structure, so I need to build with that availability/cost in mind.

The questions I have are how tall can you go before wind becomes an issue (we are in tornado country), and if you had a shed roof (slanted) would it be less desirable than a typical gable roof? Prevailing winds are from the NW, and the peak would be aimed South, so it should deflect some, but it's also a larger surface to push against.

I'd like to eventually have a deck for the second floor, so that could be incorporated to help keep it from being too skinny.


The foundation will be concrete pads. It'll have a full ground floor for structure.

 

[ace10]

...
The foundation will be concrete pads. It'll have a full ground floor for structure.

What exactly do you mean by concrete pads as a foundation?

 

[Jim Timber]

The set in place blocks. Not a drilled/poured foundation.

 

[Shenandoah]

Jim,

Building codes will most likely not allow for those 'pads'. They certainly don't in my area for any structure where the roof edge is 10 feet or more off the ground. That includes the gable ends. Any two story building will exceed those limits.

Additionally, you want to have the structure firmly anchored to the ground as much as possible without allowing for wind to get under the structure and lift it in high winds. I know it will be heavy, so is a fully loaded Boeing 747, lol.

I would strongly suggest a trip to your local building authority to get some real answers and parameters for what they will allow you to build. You'll most likely need a building permit for a structure that size. We need one for anything over 180 square feet around here, as an example, unless it's a farm outbuilding. And many times they dictate the HOW to build for certain elements of the structure.

 

[Jim Timber]

Well, it is a farm outbuilding, and a permit will have to be pulled for the size. The only height restriction is that it can't be over 34' mid span without a variance.

I'm trying to avoid needing equipment, as there's no access. I'll use a generator to run my air compressor, and haul everything in via atv trailer.

 

[BHD]

If one does a story and a half type build you do not increase the height that much, over a single story building, this is one I spotted and considered, I wanted a little cabin,





the original barn was,

Ashokan Barn Plan
I felt that not filling in the back corner would be a waste, and I for the cabin Idea wanted a sleeping loft that would be nicer,

 

[ishiboo]

I'm in the design phase of what will be a utility shed on the main floor, and a bunk house/ lounge on the second story.

I'm thinking 16' wide would be nice, but only want to make it 20' long. I want a full 8-9' ceiling on the ground level, and at least a 7' ceiling upstairs. I'll probably be using dimensional lumber for the structure, so I need to build with that availability/cost in mind.

The questions I have are how tall can you go before wind becomes an issue (we are in tornado country), and if you had a shed roof (slanted) would it be less desirable than a typical gable roof? Prevailing winds are from the NW, and the peak would be aimed South, so it should deflect some, but it's also a larger surface to push against.

I'd like to eventually have a deck for the second floor, so that could be incorporated to help keep it from being too skinny.


The foundation will be concrete pads. It'll have a full ground floor for structure.

You can go to 2-3 stories with conventional building methods with no issue.

But you're in tornado country and worried about wind. No matter how small of a building you build, it's waiting to be picked up/moved when built just sitting on concrete pads. I'd never build anything that substantial simply sitting on pads.

Given the remoteness, I would recommend building it using a post frame method with posts set into concrete, then stud/side conventionally with OSB or wood paneling thus making shear walls. This will be a very strong structure that is also economical. It will be easier to get bagged concrete out there, and all you need is a post hole digger for the holes.

 

[hddnis]

What about a pole building?

I don't know if code allows them in your area, but they are fairly common here and many are a garage on the bottom and living quarters on top.



Mr. HE

 

[Jim Timber]

This will be insulated, and covered in hardy boards. I'll run heat of some form in the winter.

Pole construction isn't a bad idea, but poles that long get expensive, and it would require a much more substantial main floor to keep from heaving in the middle where the joists weren't supported with footers. We have 5' frost depth. I mainly wanted it free floating to constrain costs/labor. I could anchor it down like mobile homes do. Maybe I need to get my buddy's Alaskan mill for a week and make some pole and beam wood when it comes time to putting this up. I know my 71cc Jonny isn't ideal for milling.

Loft for sleeping isn't what I want. I want a loft for occupying at walking around not hunched over height. It will serve as a living room (why I called it a lounge). I'm 6', and I have friends and family who are 6'4+. 7' minimum upstairs at full width, no less. I also despise dormers with a passion, and barn roofs make me vomit.

 

[ace10]

You can stick build on a wood pier foundation. Strength of traditional residential construction without the need for yards and yards of concrete.

Under no circumstances would I occupy a structure that relies solely on gravity to hold it in place.