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Hello All,
I am playing with some modular design ideas, you know, make everything fit to a 4′ grid, and I have run into a question that only a contractor can answer. Specifically, how much can a rough opening be larger than that specified by the manufacturer, and still work? And how much of a pain is it if the difference can NOT be made up exactly w/ standard lumber. As an example, w/ 2′ o.c. studs, one bay would leave 1′-10 1/2″ as the rough opening. Eagle makes a 1′-8″ wide window that specifies a 1′-8 1/2″ rough opening, i.e. exactly 2″ smaller. With 1X lumber on each side, this could be brought down to only 1/2″ too big. How viable is this from the standpoint of the designer wanting the builder to think said designer is one swell guy, rather than one $!@#$%! Once the difference get’s much bigger than this, the difference would need to be made up with 2X lumber, and you would start loosing the material benifits associated with designing to the module. For that matter, is there a window manufacturer out there who makes windows designed to fit between standard stud bays? You would think this would be a nice little niche market.
Anyway, thanks for the input.
Gordon Price
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Gordon,
You can spec your own sizes to window manufacturers. If you want a 1' 10" window, you can order it made that way.
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Yes, but at that point you are dealing in a custom window, are you not? Part of the benefit of designing with the module is standardization (and cost savings), but not very many windows actually fit in a standard stud bay or combination of stud bays. It seems to me that a window manufacturer could make some money by being the only manufacturer to offer an entire line of windows designed to fit perfectly in a combination of 16" or 24" bays. I have been looking over the various catalogs and making a list of windows from different manufacturers that fit comfortably in different stud layouts, but that definition of "comfortable" is one that I think the contractor defines, along with the material use and cost issues of filling in a standard bay to get a window to fit. For the moment I am assuming that trimming the hole with 1X material to get the rough opening to no more than 1/2" larger than the suggested RO is O.K., but I would like to hear if that 1/2" is such a large gap as to make it easier to add studs and get a correctly sized hole. I would also think that a window with a nailing fin would make it easier, as long as the fin allows you to drive your nails at various distances from the frame. On the other hand, I would think that extra shimming with an all wood window would be a real pain.
Of course one way to learn all this would be to just make a decision one way or the other, then go politely listen to the builder who hates the idea, and develope from there. however, the less abuse I can invite, the better ;)
Regards,
Gordon
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Gordon,
What does framing lumber cost where you are? How many studs are you going to save and what will the cost be per house. Plan on dealing in major volume? If you build a house for me, I'll give you a couple hundred bucks extra if you promise not to scrimp on studs. I think they help keep the roof up. While I'm in favor of not wasting resources in building, I think there are better ways to approach it than this. How about cutting down on the total sq. footage, eliminating a bathroom or at least a jacuzzi? Run the numbers. The only people I know who are seriously concerned about saving wall studs are framing subs dealing in volume. $50.00 a unit is $5,000 in your pocket every 100 units.
JonC
*No matter where the window is or what size it is, it still needs jack studs, cripple studs, a header, sheathing cut, drywall cut, casings installed, etc. etc.putting studs on 16" centers instead of 14-5/16" centers makes work alot easier but worrying about the size of a window doesn't save much in time.By the way, I pay for windows by the unit inch. Same price per inch if it's in stock or made just for me to my size. To answer your question: 1/2" over recommended RO is no problem. It's sure better than 1/2" under.
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Correct me if I'm wrong but isn't 16" OC based on a 4' grid? 4' drywall, 4' plywood etc. 24" OC is okay, I guess, but you would never sell me on the inferior strength in the design. I'm not even sure it's allowed by code.
But that's not your question. If you want to use 24" centers I'm sure you save enough lumber that you can afford to make a few ecceptions where applicable and frame the ROs to the corect sizes. I they're already framed and a 1x brings you to within 1/2" of spec then I guess the window won't fall out or anything like that. But, as Ryan C points out, many companies price their windows by the square inch whether they are off the shelf or custom fit. And the ROs in new framing should be done to spec no mater what centers (16" or 24") you're using. By the way, the space between 16" and 24" is 14-1/2" and 22-1/2" respectively. Also, we here in the midwest do 16" OC for peoples homes and 24" OC for garages and sheds (sometimes).
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I'm sure Gordon that in your study of stock window sizes you found not much "standard". My suggestion to window manufacturers would be to at least get a cpl that fit the same RO. In your case, just spec the size and location and let the framer make the opening. That'll save time and money. People do layout different. I think it would be better to get the window where you want it rather than where it falls on layout.
*Am I the only one who thinks a 1' 8 1/2" wide window would look lousy ?
*Yeah, that's the critical point: getting the window where you want it. If you start with the window, and then lay out the wall, going by Gordons suggested method, you're going to have troubles somewhere, at least at the corners.On the other hand, I can really see where Gordon is coming from in trying to use the module at it's most efficient. There is a reason people started designing strucures based on modules in the first place.
*Gordon:Are you serious? You are putting all this work into finding a window that is less than Two Feet wide? Surely you can't be using more than a couple just to get light to a specific location, because that is all they are good for.Or, maybe this is the snooze relief post of the day?
*Nothing effects the aesthetics of a house like window and door size and placement. They either look right or they don't. I have seen houses where a window or two were slipped a few inches right or left to put the RO on a stud. If you back up and look at it you can tell.Incidentally, the kind of windows you propose are already being made for the mobile home industry.Steve
*No sir Ron, you're not alone.
*At the risk of stirring up trouble, have you investigated SIP's rather than stick framing? Then you can put windows pretty much anywhere you want, in any size. One maker around here (R-Control panels, http://www.teamindusties.com) allows up to a 48" opening without a header if there is no point load above. If you engineer the house to use SIPS I think it's a better way to build.did
*RonI like the 24" on center 2x6 fraiming can do a 12 foot wall. with the 22 &1/2 wide windows you can frame with out regular headers no criples no jack studsjust 2x6 blocking top and botttom for the siding sheithing to nail onto. because your studs run all the way from sill to plate. with a 4 foot shear pannel on each end going all the way up and one shear pannel say at least every 30 feet a series of such windows gives you the parrie house effect I think the catchy name was good cents framing
*Gordon, I've read all the posts, and I still don't get it . Why would you want a house with windows that only have a 1' daylight opening? Is this to save on lumber? The window mfgrs. don't make them because there isn't the market for them. You will regret any "savings" you realize with this plan when you try to sell the result.
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Steve (and all),
I think the example given was a bad example. The idea is to put all the studs exactly on the module, and intentionally choose a window that will fit in that module (and serve any other purpose required) be it 1 bay or 4 bays. By keeping all the studs exactly on module, you can also have interior walls that center on the module, and have a garanteed stud to back up against. As for the 1' window, it does have a purpose on occation. Because it fits in a single bay, it needs no header, so you could have a string of square ones side by side, up high, bringing daylight deeper into the room, without loss of privacy, or exposing a bad view. The only limit on how many would be the required shear in the wall. With a moment frame, you could use them to almost float the roof on the walls. Also, a 1' wide window that is really tall can be very nice to frame a view, such as a tree.
An for the original question, I realized that any window that fits in multiple bays will still need a header, and therefor trimmer studs to support the header, so the default RO is reduced by another 3". I will have to look again at the available sizes and see if that makes more available.
Also, it is interesting that the modular idea seems to not be as popular as I had thought it would be. I expect designers to balk at the idea, "It's a crutch, you aren't being creative", and forgetting that FLW was modular on almost all his residential designs. Maybe I should start a thread on how modular SHOULD work (from a builder perspective), and then just sit back and take notes ;)
Regards,
Gordon Price
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No matter where your window falls, the sheathing and drywall above the window will fall on the header and therefore you have good blocking for the seams.
No matter where your window falls, you can put a cripple stud below on 16" centers and again a full sheet falls in the right place.
As for the windows themselves...no matter where they are or how big they are, you gotta cut the sheathing for them anyway.
Modular design is better than random spacing but too much of a good thing isn't necessarily any better.
*Deleted my previous to add an attachment...Gordon, In regards to your first theoretical setup, with single stud bay windows (non-stuctural, no structural header or cripples required): You still need a simple sill and header for nailing purposes. Header, since non-structual, could simply be a 2-by on the flat. To fill in excess width, do it however you want...an extra 2-by nailed off on one stud with a length of half-inch ply on the other, etc.Once you break a stud and get into windows that span two or three stud bays, now you're looking at doubling (possibly tripling) up your studs (jacks/kings) and adding structural headers and cripples. If you had to fill in 2" on an opening that spanned two studs, I'd add the jack on one side of the window opening to the inside of the window opening, reducing the width of the opening by 1.5". I'd add the king on the other side of the window opening to the outside of the modular stud, the modular stud would now be the jack. Add a half-inch filler of ply to the inside of the opening on either side and your opening is reduced by the required 2". I'll attach a quick sketch as my words seem garbled even when I read them. The top part of the sketch shows what I'm trying to get across in the above paragraphs.I think it's perfectly feasible to layout your 2x6 studs on 24" centers. I also think you can save materials by having one side of all windows use one of these "modular studs" as the king stud for the window opening and letting th other side of the window fall where it may. See bottom portion of attached sketch.I do not think it wise to limit yourself to windows that fit into these rigid 16" or 24" framed openings, though. Windows do need to be scaled to the size of the structure, to the proposed use of the room, and to the intended view outside that room. By at least having one side of the window fall on a structural stud you'll still save a few in the process. Trying to be too frugal, while admirable, can result in nasty looking structures that are unbalanced to the eye and frustrating to the homeowner trying to enjoy the view from inside the structure.
*Gordon, most ro's can deviate by 1/2" without causing too great a concern. Your idea to fit a window into a modular stud bay is misdirected however. The bigger savings is accomplished by the window manufacturers that use standard sized glass panes to manufacture their stock windows. Glass comes in standard sizes just as plywood does. I believe that glass uses two inch increments. Your idea would save $1.89 for a stud, but cost $150.00 for the additional cost of creating unstandard sized glazings. It sounds like a guy who is spending dollars to save dimes.Keep up your effort to save the owls however. I'm the biggest owlsaver in this forum (Ithink) and admire the thought process.blue
*The four foot module is a useless misconception often...I have on the job changed roof overhangs less and inch to stop form putting on a inch strip of plywood, and also I have moved an interior partition so carpet wouldn't need to be seemed...but I really don't care about four feet in general...two feet near the stream, four feet in the sack, aj
*I've done the same (or similar) thing Jack. Four foot modules work well for plywood but the last time I looked, houses were made up of more than plywoood!blue
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Hello All,
I am playing with some modular design ideas, you know, make everything fit to a 4' grid, and I have run into a question that only a contractor can answer. Specifically, how much can a rough opening be larger than that specified by the manufacturer, and still work? And how much of a pain is it if the difference can NOT be made up exactly w/ standard lumber. As an example, w/ 2' o.c. studs, one bay would leave 1'-10 1/2" as the rough opening. Eagle makes a 1'-8" wide window that specifies a 1'-8 1/2" rough opening, i.e. exactly 2" smaller. With 1X lumber on each side, this could be brought down to only 1/2" too big. How viable is this from the standpoint of the designer wanting the builder to think said designer is one swell guy, rather than one $!@#$%! Once the difference get's much bigger than this, the difference would need to be made up with 2X lumber, and you would start loosing the material benifits associated with designing to the module. For that matter, is there a window manufacturer out there who makes windows designed to fit between standard stud bays? You would think this would be a nice little niche market.
Anyway, thanks for the input.
Gordon Price