Hey framers – I have a question about window rough opening framing. I’m designing my own house to be built in Missouri (90 mph windcode?)What I’d like to do is group windows together in a long run ( 8′-12′ wide), but use seperate windows instead of factory-mulled, to get the built up trim inside with cheaper vinyl windows (and also less header). I would do typical kingstud and double jacks each side, and i guess divide each rough opening with double 2×4’s from sill to header, blocking under the sill and over header for bearing to plates at each opening. I only want about 4″ trim between each window, otherwise I’d frame as usual with single jacks and kingstud for each window and stackem’. Knowhatimean?
I’ve never come across this before, and it seems like it would be a weak spot in the wall of windows since each kingstud doesn’t go plate to plate. I’ll have 1/2″ osb sheating if that helps. Maybe there’s a connector I could use also?
I don’t build full time, so maybe this is normally done?
Wondering if anyone’s done this before. Thanks.
Replies
Questions:
What is this wall supporting? Is it on the truss or rafter ends or on a gable wall with trusses.
How far are the windows from the corner or end of wall?
How long is the wall, how tall, and how tall are the windows?
And what’s wrong with more header?
Depending on your answers and not knowing now, I would run a continuous header and extended it at least 2 ft past the windows. By extending it past it will help keep the wall straight and not want to fold in or out a little by the window ends
Kgmz -The house is 9' ceiling, 12/12 pitch cathedral with structural ridge, no collar ties. Window groups start about 2' from outside corner average. Walls are 2x4. I'm wanting to keep headers light only because I'm building it myself (no money=no crew). I'm not as concerned about header size as I am nailing windows into double 2x4 that seems "scabbed" into the rough opening (toe nailed or kreg jig).Some of the windows are in rafter bearing walls, but the biggest set is in a 24'wide full gable wall with no interior partitions. Also the post for the structural ridge bears on this biggest set.I'll see if I can figure out how to attach the exterior views in a little bit.Thanks for the reply.
"Also the post for the structural ridge bears on this biggest set."That says you definitely need engineering help
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Thanks - I'm working towards engineering and finishing the plans.
Anybody know a structural engineer in the St. Louis area?Appreciate it.
Running the header past the opening by 2 feet! Man! That is a great idea!
"I would run a continuous header and extended it at least 2 ft past the windows. By extending it past it will help keep the wall straight and not want to fold in or out a little by the window ends"
I don't see where that would accomplish anything at all. You're moving the "hinge pioint" away from the windows a couple of feet. But it's still a hinge point.
By making the header longer, you're also making it weaker in the bowing in/out direction.
I wonder if the OP would be better off using short headers over each window with Simpson "Header Hangers".
Passing gas is necessary to well-being. [Hippocrates]
Some people extend headers past the window so as to have a solid block to hang curtain rods on. I suppose someone seeing that might think it was a structural issue and then go on thinking it was necessary, and teh urban legend is born.
Running headers extra long and up against the top plate can ease the pain a bit if they change their minds on the size or location of windows.
-- J.S.
In washington state you always have to run garage headers full length of wall if walls are shorter than 48"? Can't remember exact length, but it is very common for the wall to the side of the door opening is 16" to 24". Our code calls for the beam to extend full length of "wing wall" and when sheathing is hung you pepper the sheathing ino the beam. If the shear nail is called out 2" o.c. you must have a nail every 2" in a series of squares the entire surface of the beam where it sits on the walls. Pretty typical to have seismic hold downs at each end of the wall and the nailling pattern above the H.D.s attaching sheating to double studs/trimmers must be a double row of said shear nailing. It's not uncommon to have the same detail called at oversized windows where there is not enough wall left for proper shear.
I have done large headers in walls that you couldn't get seperate king and cripples in.
I use 1/2" osb on the outside sheathing and then use simpson 2.5's on the top connection where the short cripples hit the header.
Just remember where you put them and try not to shoot them with your trim nails.
You're such an inspiration,
For the ways I will never choose to be.
Stilletto - H2.5s - good idea. Besides, I love trimming houses with steel and nail heads poking out everywhere - not! :) It seems like the sheating would help hold things together too. Maybe I'm worrying too much.Thanks.
Are these plans engineered or are you even required to get them engineered where you are.
Around here just about everything needs to be engineered.
Just wondering if you have any shear panels, etc. with that many windows and so close to the corner.
I would build this just like you would do a double garage door opening with portal frames. And have attached a drawing.
View Image
Don't know for sure where the windows are, how many, and what the percentage of total wall they take. And if the post for ridge beam fall on a opening. But this drawing will give you the idea.
If this was my house I would run a header beam end to end just like you would with a garage door with shear panels at the ends. I would toenail the studs to the beam with what could be called a pressure block inbetween like you see in the pic in the upper window openings. The block will keep the studs from moving and no need for straps, etc.
Wow - thanks for taking the time to draw that up. That's exactly what I'm talking about. I was still stareing at my cheap cad program wondering how I was going to put it on the internet.I see what you guys mean by running the mid jacks down to the plate. The way I thought up seems pretty rickety after seeing that. Also the pressure blocks help take care of the shear and twisting that I was worried about. I'm just trying to break the header span up cause I'm cheap, but your right - think garage door header sectioned off. could always do a fetch (sp?) plate in place if I had to. I'll let an engineer tell me that.But now I can go forward with my plans and seperate window idea.
Thanks all! Onward and upward!
That snazzy diagram is how we'd frame it, and have framed others in the past.
The doubled jacks between the windows are usually spec'd from the arch or engineer with Simpson straps of one sort or another on both sides of the header running down the jacks. Very stiff.
Since the doubled jacks, even 2x4 jacks, can support a great deal of weight it's usually the case that the header is sized to span between the jacks, not the entire span. On the other hand if, say, you wanted to use a single jack, it may or may not be up to the task depending on the window opening and the header would get sized for the entire span if needed.
We always put the header as high as possible in the wall, or in the rim if a two story house. The higher the header is, especially with taller walls, the stiffer the wall will be since it creates less of a hinge with the taller jacks.
Good building.
Beer was created so carpenters wouldn't rule the world.
The block will keep the studs from moving and no need for straps, etc.
I'm a big fan of blocking of all kinds, although in this situation it would need straps to pass our local structrual insp., not that it's required everywhere, or even specifically spelled out in IRC or UBC.
As you've said, the sheer wall issue may be a larger problem than the header, depending on how many windows are in there and what kind of wall is left over.
Beer was created so carpenters wouldn't rule the world.
when you say, "just like you would with a garage door with shear panels at the ends"... are you talking about a system similar to what is on Page 8 of this APA guide?http://www.apawood.org/level_c.cfm?content=pub_searchresults&pK=tt-100&pT=&pD=&pF=YesJust curious.
This looks fine. The one note we'd have here in earthquake country is that the ends of the header have to be well secured to the adjacent king studs to keep it from rolling over.
-- J.S.
That looks good - given that he still has an engineer size things.
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I don't see anything wrong with your idea except that I would run the jacks to the bottom plate instead of breaking them on your sill.
For an 8-12' header, you might need triple king studs and triple jacks on each end, depending on your load and weight above. You can then put in 2 or 3 jacks to divide each window to get your ~4".
Run your OSB continuously from the header down the jacks (either sawzall or router your window openings (or chainsaw)).
I have done just that in the past.
I like the idea of running the intermediate jack studs to teh sole plate. I think that would stiffen things up a bit.
You say "For an 8-12' header, you might need triple king studs and triple jacks on each end, depending on your load and weight above. You can then put in 2 or 3 jacks to divide each window to get your ~4"
Why triple jacks on the ends? The reality is that the intermediate jacks will carry load and in affect make the 8 or 10 or 12 foot header more like a series of 3ish foot headers for load purposes. As such there is no need for more bearing surfaces on the ends, and the header could also be lightened up. I would likely still go bigger than lighter.
And why triple kings? The kings don't carry anything. I suppose three studs tied to the top plate gives you more nailing surfaces in order to tie the whole window unit into the top plate. But then again the sheathing above the windows do also and probably more affectively.
Not really questioning you as looking for logic to learn from.
I was just going off the top of my head last night...but I've got my JLC field guide in front of me now.For 36' of building width and 50 lb. snow load with an upper floor and a truss roof, you need 3 jacks for a header span of 4-11. That's a pretty extreme scenario, but I really didn't know what he was working with.I can't tell you why you sometimes need more king studs, I just now that it is sometimes the case. Many times we'll have double kings and jacks called out on the plans on larger window openings. Oftentimes on garage door headers (and this is when I lived in FL), the engineer would spec3 or 4 king studs on each end.IIRC, it isn't so much the downward force; with a big span, the king studs would have a tendency to deflect, or bow out, and doubling or tripling them helps prevent that from happening.I'd be interested to hear what forces are actually affecting the header assembly.
"the king studs would have a tendency to deflect, or bow out, and doubling or tripling them helps prevent that from happening."If the king stud is properly nailed to the trimmers, why would it be able to bow, esepcially if there are two or more trimmers on each end?
I'm not sure, I just thought I recalled someone telling me that at some time or another.Do you never have to double kings?
I've never seen it specified on plans nor has an inspector ever required it. I just double or triple the trimmers as needed, and usually that's not specified, either.
Sure. If the header beam is dropped, doubling the king posts is a good idea.
Edited 2/22/2007 12:09 am ET by fingersandtoes
If the king stud is properly nailed to the trimmers, why would it be able to bow, esepcially if there are two or more trimmers on each end?
Lets apply your question to a somewhat different type situation than you normally are used to seeing and see if your theory always stands up. I'm assuming that you are picturing a 8' wall with the header up tight and two trimmers nailed to a single king stud...right? Your question and thought process has merit in that case.
Now, lets look at a different arrangement, one that I've seen many, many times. The wall I'm thinking about is a tall garage wall....say 14' tall studs. The 8' garage header is positioned 7' off the bottom. Somewhere in the midspan of that 8' header is a point load so the header is a serious micro of some dimension. Using your theory, you'd be comfortable with three trimmers and one king stud. In theory, because of my experiences in the field, I know I'd much rather use three king studs and only one trimmer! In reality, I'd use a minimum of two kings and probably put two trimmers.
I remember seeing some Pulte plans that called for seven studs under a point loaded header or a steel column. To satisfy their engineers, we'd put two trimmers and five kings. I worked for another tract builder that always specified how many studs they wanted at the edges of headers. I had the superintendent clarify with his engineer whether he wanted extra trimmers, or extra kings when they called for four studs at the ends of the headers. They wanted extra kings. We often had headers with one trimmer and multiple kings.
The idea is to stiffen the post to prevent bulging.
blue
"...if you just do what you think is best testing those limits... it's pretty easy to find exactly where the line is...."
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Aha. Makes sense that you could have deflection in the middle of a 14 footer like that. Working on the old places that I do, I just don't encounter any wall much taller than about ten feet.
Op here. Drawing attached (hopefully) a little too late. Sorry if they're too big for dial-up - I can't remember how to downsize.Anyway, the bt south view is the longest window span, about 12', and the main one I was concerned with because of the ridge post bearing on the header. Bt south is a 24' wide room with cathedral ceiling, structural ridge. Room is 18' deep ( to other ridge bearing ) if that matters. Other view isn't a concern - just want to divide all windows with double jacks. This level sits on 8" concrete basement wall and the whole house is spray foam insulation which I think stiffens everything up. AR shingles, 2x12 rafters, 20 lb snow load... Ignore the chimney being short - still deciding if I want a red or white flashing light on top after it's raised :)Also, not to change the subject, but I don't know if I need an architect if I have a working plan. Somebody mentioned door swings, etc. I will have probably too many details, floor joist/ rafter spans, finish materials, fireplace details, staircase, etc., so I thought I could just get the 2nd level floor trusses and the structural beams sized, bearing paths called out, pay an engineer to check and stamp it (county required), and be good to go. It's just 2 x 4 platform frame on a pretty normal house.Like I said before, I just haven't dealt with architect/engineer much in the past - built simple houses that an architect would probably roll thier eyes at. Anyway, sorry to be so stupid on the subject. How does this usually work?p.s. - just attached file - 1692kb? - that doesn't sound good. We'll do one for now.
Ok, bow on the kings. That can make sense. But wow! 3 jacks and 3 kings, that makes for 9 inches of post. Not likely much bow in that puppy even with 16 foot garage door with roof load!
This is good, just wanted to add, glue exterior sheathing and try to bridge the hinge point as much as possible.
I read both your posts,get an architect. The cost of an architect will be made up in lost time,possible code infractions and many other problems too numerous to post.
Have fun designing your home ,but make sure a qualified person at least looks over your sketch
mike
Great tips - thanks. Mike , I agree - I'll have to get the plans structurally engineered anyway, so maybe I'm jumping the gun. The houses I've built in the past where simple with full span truss roofs, window openings under 6', so I haven't dealt with engineering or architects before ( except the guys at the truss plant ). I didn't think an architect/engineer would call out framing methods. I still might try attaching those CAD drawings. Looks like a PITA, though.
The main reason I'd want to get engeneering around here is our earth quake codes, not to mention our building depts. would laugh me out of the building with my preferred method of scetching ideas on the closest two by. That said, the real concerns are live loads, shear factors and from what I understand, how all the elements play together. From architects I've worked with I have learned that a lot of the engineering is done by computers, obviously, with the drawback being that often times you are practicing extreme overkill due to a program that is only as good as the info input where as in the past somebody was breaking out a slide rule and figuring out the specifics to you project[boy I bet I get a lot of mud for that statement] The upside of course being speed and a lot of people using the swame general parameters.. That said, better overkill than under considering it is carying your ridge.
As to the king stud/trimmer[others are calling it a jack stud I think]in western Washington single trimmers up to 4' spans, double trimmers over. The picture posted showing the mid-span trimmers from plate to beam is exactly how we do it, typically just toe nailed though we sheet every thing here with ply or osb. I think the pressure block is a great idea for keeping every thing square. Another plus to engineering is bearing points. I've never personally seen a call out for multiple king studs, but I depend heavilly on the engineering as our stick framed houses are about 50%simpson hold down anymore. You could pick up our houses with one a them magnets on a crane!
mike , you say "Have fun designing your home ,but make sure a qualified person at least looks over your sketch"
Are you mostly concerned about a structural review or a design review? If structural, why an archy and not an engineer?
This seems like an structural issue.
That said, I do think many people design pretty crapy houses and forget dozens of details, door swings, common ergonomic issues, and just butt-ugly cubes.
My son is an architect, so naturally I would prefer him. Either for structural issues,architect for both design and structural.An architect may have a structural engineer review his drawings, depending on the complexity of the design.
mike
Looking at the number of replies, you probably have more answers by now than you were looking for, but I feel like yumping in anyways.
First - if the kingstud does not go plate to plate, it is not a kinge stud. It sounds like you are thinging continuopus header, but the way i frame these would be with a header above each windowseparated by one king that is flanked by two jacks, one on each side.
That said though, it could be that your design is getting close to needing engineer stamp for shear and wind load
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Some great ideas thus far ....As owner builder youre building for youself, but you are also building for the B. Inspector. So I would talk to the man first, see if some parts of your plans need a engineer's stamp. In high wind areas make sure youve got positive connection from roof sheathing, (with proper nailing) to rafters-trusses to wall and below. If in seizmic area everything changes, and if building dept requires then problaly will need egineered plans. Some things weve done. First of all I have used your idea of separate windows several times but generally speaking you will save money with mulled windows. I mean if youre doing the work yourself it might be a wash, but if youre paying for labor ......Also applly the chip in such a way that it covers all the header -stud connections, plates, and rim joists, in a way, overlapp everything. Also I dont think you can get solid 4x stock for headers in Missouri so if you build up headers glue them together with adhesive. Use lots of solid blocking. trimmers-jacks must be one piece from plate to header, and Dbl up for longer headers. An inspector once told me, (a remodel) when putting in a header and there is some question, ply both sides, you end up with the whole wall becoming kind of a box beam. Hope some of these suggestion are helpfull.