reframing opening in balloon frame
I’m installing new, bigger windows in the 2nd story of a balloon framed house. I’ll be spanning one more stud than the old timers did for a total RO of 34 1/2 inches. The old-timers skipped headers all-together but I figured I’d install them since I’m opening up the walls. Here’s my problem, what can my jack studs rest on? Would a good fastner into the existing studs be sufficient? Any other solutions? Ripping out the walls on the first floor is a no-go at this point.
Often there is not much weight to support above on the 2nd floor. If you have a pitched roof above, much of the force is often lateral and outwards, depending on how the roof is framed. I have seen this sort of alteration result in roof spread. If you have lateral loads, you would need a very different header approach.
Anyways, you have a few options I can think of for a conventional header.
One is to run the jack studs down to the rim joist, if you can get them in. Most of the balloons I have seen have a let in rim joist between the floors. These essentially act as a 'header' for the 1st floor openings in many cases. You should consider if you are shifting a point load to a position over a 1st floor opening with these mods.
Another option would be resting the header on heavy angle iron through-bolted to the ajoining stud. You do not get the 'doubling' effect, but it is better than what you have now.
A third option would be to just run the jack studs short to nothing. If you through-bolt them to the adjoining stud, they are as good as the steel, and provide some amount of stiffening to the stud.
Waiver- None of these may be code-approved, though the first is the most likely to pass muster- Also, I am no engineer and obviously have not seen what exactly you are up against.
Thanks Snowmon. Your 3rd option is what I was considering. I'm working with a hip roof and the windows are just below the top plate. The rafters rest on a cantilevered ladder-style assembly that juts out a foot to form the eaves. Second floor joists are toe-nailed into a 1x ledger except where they run parallel. Then the first joist forms a "rim."Very aware of the point-load issue you mention.
I've used Simpson HH4 hangers in that situation, and just extended the header to the next existing stud. "Headerless" balloon framing was actually made pretty dang stiff by use of 1" sheathing boards on both sides, but most often the interior layer is long-since gone in favor of insulation & drywall.
I'll check out the simpson hangers. Those sound like an easy solution. In my house a layer of lath and plaster was applied between the studs. So there's 3/4 sheathing, the "hidden" plaster, then lath/plaster inside as usual. Pretty tight house. I still have the plaster and will be preserving as much as possible, replastering what I take out. Not a big fan of drywall
With HH4s and minimal finish disruption, you can drill through the finish to expose the holes on the vertical tabs that engage the existing studs, then attach with 3" screws using a long-ish bit. The tricky part is getting everything in place. I like to wedge the hanger ears between the stud & exterior sheathing, cut enough interior finish back to allow bending that side of the hanger down, cut the header about 1/4" short, install, re-bend, and screw. Header thickness finishes at 3-1/2" with HH4s, so there'll be some shimming involved. HH6s are also available. I haven't checked codes for this, but haven't had any gigs.
I looked at the loads on the HH4 and it looks like it'll work in my application. For some reason I find it easy to forget about those steel products--thanks for reminding me.
A second vote for the simpson hangers to avoid header jacks altogether.
The inspectors in my region allow you to just run the jacks as far down as you can and nail them off real well. I like the idea of the simpson hanger though.
Remodeling Balloon framing can be dangeruos if you don't play it safe. Exterior load bearing wall, build yourself a temp wall to pickup joists and roof loads.
If you have the wall open, I would put in 2x fireblocks down at the 1x let-ins in each stud bay and use those new blocks as your plates for the trimmers.