Re -wiring , insulating ,& rocking an old house .1 story studs 2x4 16 OC, Rafters 2x6 24" OC?
Answers:
The best thing for you to do is to find out what code your municipality enforces and refer to that code. In most model residential codes, a second floor is easily allowed to be supported by 2x4 stud walls with double top plates. The largest problem you normally have is calculating what size floor joist will be required to span between the existing downstair wals.
That is really not a problem for you though! There will certainly be a floor joist supplier/vendor that will have a standard load/span table and can size them for you. They will also usually know what code your municipality is enforcing (if they're in your muni) so can size the joists for the loads the code requires.
This is really not a big intimidating deal as others might have made it sound.
I always recommend an Architect but a capable builder will be just fine too most of the time. As far as your city requiring an Architect's stamp, MOST do not. It is odd they would require it for residential work. Especially if you build "out of the book' as it is called when you build to model codes. The city will def. want a PLAN and will do a review themselves.
A home designer might be the person you would want to contact about this.
So to answer your original question, USUALLY 2x4 studs at 16"oC will support a second floor used for normal living.
Good luck.
Other answers:
What the hell do you mean "sister out the studs"? I've been framing for many years, so it's obvious to me you have no idea what the hell your talking about or asking. So let me help you, you moron. When you build a second story on an originally one story family house, you do what is called "platform framing". Platform framing is the standard for all multi-level houses anyway. At the top of your existing studs, along the outer walls of your house, you will notice two 2 x 4s stacked on top of each other running horizontally. These are called "headers". In 2 x 4 construction, all load bearing walls must consist of two 2 x 4s stacked on top of each other. Now, when you look at the tops of any interior walls, if you see two 2 x 4s stacked horizontally on top of the studs, you'll know it's a load bearing wall. If there is only one stud, it is not a load bearing wall but rather just a partitioning wall. When adding a second floor, all loads must be carried by load bearing walls only. You cannot use partition walls to carry the weight of the floor joists above. The floor joists must be attached to load bearing walls only.In addition, you want to line the floor joists up wherever possible with the studs below. I could go on and on about this stuff but I can tell that you'll never be able to do it yourself cause you're a loser, so just hire a contractor ok?
What the hell do you mean "sister out the studs"? I've been framing for many years, so it's obvious to me you have no idea what the hell your talking about or asking. So let me help you, you moron. When you build a second story on an originally one story family house, you do what is called "platform framing". Platform framing is the standard for all multi-level houses anyway. At the top of your existing studs, along the outer walls of your house, you will notice two 2 x 4s stacked on top of each other running horizontally. These are called "headers". In 2 x 4 construction, all load bearing walls must consist of two 2 x 4s stacked on top of each other. Now, when you look at the tops of any interior walls, if you see two 2 x 4s stacked horizontally on top of the studs, you'll know it's a load bearing wall. If there is only one stud, it is not a load bearing wall but rather just a partitioning wall. When adding a second floor, all loads must be carried by load bearing walls only. You cannot use partition walls to carry the weight of the floor joists above. The floor joists must be attached to load bearing walls only.In addition, you want to line the floor joists up wherever possible with the studs below. I could go on and on about this stuff but I can tell that you'll never be able to do it yourself cause you're a loser, so just hire a contractor ok?
first of all,Son of Bruhn whoever is an ***.the 2x4's he is refering to are called"plates"headers are the large pieces of timber located over doors and windows,in California anyway.To legaly and properly add a second story,you need to have an architect/engineer do a load calculation,then provide a drawing to the building department for a permit.the drawings,or blueprints will specify what dimension lumber you will need to use.I suggest hiring or atleast consulting a proffesional.
Wow.... That was rough, however accurate. There is only so much information one can pass on in this forum. Some things take years to learn, and longer to master.
You do not have to sister any studs. You may have to add additional load bearing walls to the first floor, depending on spans, and dimensional lumber you choose.
Even though the first post was rather abrupt, it was accurate.