Stud Location?
Stud Location?
(OP)
Is there a provision in the code that requires studs to be placed directly under floor joist and roof rafters/trusses?
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RE: Stud Location?
RE: Stud Location?
I understand about designing the top plate for bending. Last time I looked into that it failed miserably.
When I was framing houses during college summer vacation I was told to always locate the joist/studs directly above the joists below. This required a little more planning but was a much better system.
RE: Stud Location?
Might not be able to prove that - but it has worked for 100 years.
RE: Stud Location?
BA
RE: Stud Location?
I understand the check.
I was talking to a contractor I am currently doing a project for and he commented about my 2'-0" o.c. stud spacing. I stated that the 2' spacing was in order to make the studs fall in line with the roof trussed above. In this particular case 2'-0" o.c. didn't work for the loads so I have to reduce the spacing to 1'-0" (the contractor didn't want to use a large knee wall to reduce the height of the studs). The contractor suggested using 16" stud spacing. Once I informed him of my requirement he stated the typical "never done that before" and "the building inspector has never complained". I was just wondering if there was a code requirement that I couldn't find requiring this spacing.... otherwise when using the prescriptive IRC he is correct (in this case we are outside of the prescriptive code).
He is going to use the 1'-0" spacing.
RE: Stud Location?
I have had the same problem a few times. On one occasion, the architect wanted a 16" spacing for drywall support. The roof trusses were spaced at 2' centers and the double plate did not satisfy the code, so I specified a triple top plate. I didn't feel that it added significantly to the cost.
The architect took exception to this and sought the opinion of another engineer who argued that the double top plate was adequate based on his experience. So they went with a double top plate and I lost the job (I wasn't sorry).
If you use a 1'-0" stud spacing, it seems to me that the studs will share wind load equally, but alternate studs will feel little or no axial load from the roof. If you used double studs at 24" centers, all studs would be loaded similarly.
BA
RE: Stud Location?
Mike McCann
MMC Engineering
RE: Stud Location?
True enough, but I don't feel comfortable relying on the nailing of those items when resisting the reaction of a fifty or sixty foot long truss.
BA
RE: Stud Location?
This at is my problem. What is the capacity of the sheathing to support some of the load? If I can't justify it by numbers, I'm not going to put in on the design documents.
Also, the daughter of this contractor is a lawyer. Not going to mess with that.
RE: Stud Location?
BA
RE: Stud Location?
RE: Stud Location?
BA
RE: Stud Location?
Good point.... I agree... but that only qualifies where there is a rim joist. In particluar I am talking about roof construction where they do not use a rim joist.
RE: Stud Location?
RE: Stud Location?
RE: Stud Location?
On the jobs I worked on sheet rock was used on both sides of the studs. On jobs that I signed, when I could not get the numbers to check, I would use triple plates or other methods to distribute the load.
Another approach that has been used is to space the studs at 16" o.c., adding one additonal stud at 2' directly under the trusses.
Regarding Conventional Framing, I am not as familair with it now, as I was in the past. However I would expect that when trusses are used Conventional Framing doesn't apply.
As pointed out by Smb4050 when CF is used you must have framing that complies with the CF provisions of the code. CF in the past, gave stud size, height and spacing for walls that supported floors and roofs framed with joists. The load on the walls was limited by the maxium spans allowed for floor and roof joists. A 2x10 spanning 16' is very different than floor trusses spaning 30'.