Header for a door and shed/garage door opening

[wendigo]

Hello all,
I'm looking to build a 12x12 cabin/shed to stay in while we build a larger place.
For the moment we are building it as a cabin with a standard door, but next to it we will have a header for a larger shed type door at a later date, for the time being we will just put a window in that location.

Based on the dimensions there is only an 8.25" space between the headers, is there any reason not to extend the entire header across the wall and just place trimmers? Seems like this allow for more flexibility at a later date.

Oh yeah, some other notes: This will have a 12/12 roof, this side is the gable end, the structure will be in an area that can get huge snow loads.

[MikeT]

As usual, I will chime in and then let the real experts give you the accurate skinny:

Assuming this is load bearing, you can go the full length, but then you might need a wider header.  I don't have time to refer to a header table, but I know there is one here.

Of bigger concern might be the lack of wall space.  This wall does not appear to have a lot of bracing area.  It is definitely smaller than the prescriptive path, but that isn't a deal killer.  Still I would want others to comment on whether they think you have enough shearwall here.  Even in a small structure, you need to counteract the potential racking forces.

mt

[MountainDon]

We need one more detail; is this going to be inspected or are we simply trying to do the best but perhaps skirting code a little?

[bayview]

   Yes . . . I would also be concerned about racking.

   What if you framed for the shed door and temporarily framed in the "unused side".  You could then install the standard door on of the open side. . .   When needed, you would remove the standard door and the unused framing.  And then install the shed door.  (Please see image.)

   Or, how about a standard double entry door?

[wendigo]

Bayviewps - that is most likely the way things will end up. Thanks for the input.

As to the code question, the property is unzoned, we could build the most lavish blue tarp tent and that would be ok

[MountainDon]

IIRC, to have a door right next to the brace panel, the IRC states that you need one full 48" wide standard exterior sheathing panel at one end of that wall. Or you need to use one of the prescriptive (more expensive) narrower braced wall sections in it's place. The simplest, least expensive solution would be to have a 4x8 ft sheet of ext sheathing at either corner, nailed properly; 6" intervals along the perimeter and 12" intervals in the field (inside). 6D nails. The 4x8 sheet assumes you have an 8 ft high wall; taller wall sections require wider IIRC.

Don_P will have the info on the top of his head, tip of his tongue...

To be on the safe side you should do something that would be acceptable to a code inspector.

[MountainDon]

Link to a link on IRC

http://countryplans.com/smf/index.php?topic=6224.msg81129#msg81129


chapter 5 is on walls.

[davidj]

In CA, an "alternate braced wall panel" is 32" wide, has hold-downs at each end (with significant anchoring into the foundation), two regular anchor bolts in addition to the hold downs, 4x6 studs at each end (for the hold-downs to attach to) and closer nailing on the sheathing (4"?? 6"??).  Narrower than that and I think you get into engineering.

[MountainDon]

Let it be noted that an end gable wall like that is generally NOT load bearing so the gives you leeway on the header(s).  IF the roof framing used a ridge beam instead of a ridge board is one of the conditions where the gable end wall becomes load bearing.

[Don_P]

Not too sure about the tip of my tongue, I think you've gotten good advice, this is more background if you want to research deeper. If you can rework it to have a more generous braced wall section in there it'll be a whole lot simpler, and stronger too.

My codebook is close but is state specific on this, Chapter 6, section 602.10;
https://www2.iccsafe.org/states/Virginia/Residential/Res-Frameset.html
(The double bar in the margin means this is altered by my state from the original ICC version) It's good stuff to review and think about what they are trying to accomplish.

I had seen the narrow wall bracing techniques described in a couple of APA pdf's. You'll need to register to download but they're ok. The articles are here;
http://www.apawood.org/pdfs/download_pdf.cfm?PDFFilename=managed/F435.pdf
http://www.apawood.org/pdfs/download_pdf.cfm?PDFFilename=managed/G440.pdf
there is more at www.wallbracing .org

As an aside. If you start thinking about how beefy we are requiring wall sections to be built to resist racking and then look down and see a pier and beam foundation.. I know I'm beating a dead horse but there's a disconnect there.

[rocking23nf]

Hey what size header is normal used above a door or 3 foot window on a load bearing wall?  I was going to use a 2x6 but maybe i should go 2x8?

[Don_P]

It depends on the load being supported. I'll answer another way, a double 2x6 supporting just a roof and ceiling on a 28' wide building with a 50 lb/sf snow load is good up to 4'-1" span. Supporting roof ceiling and a clear span floor 3'-4" maximum span. Holler back with more info if that didn't clear the hurdle 

[rocking23nf]

This is just a 12x12 extension, with prebuilt trusses, i believe they are 1/4.  So I would assume 2x6 is safe... which is good cause I hate driving 15 mins to town to buy 2 pieces of wood.

[Don_P]

Probably 4/12 pitch trusses  , you would be safe with a double 2x4 header as long as the snow load isn't ginormous.