A different way of cutting stair stringers……
Hi All,
A few years ago, when I worked in a stair shop, the installation guys had a way of cutting the rough stringers out of 2 X 12 material so that there weren’t any points.
The way they cut them didn’t follow the usual sawtooth pattern of rough stringers.
The treads for our straight stairs were always 11 1/4″ wide. So I would cut the finish skirt boards with a 10″ run. I have no idea what the installers cut for a unit run.
And, of course, the rise varied from house to house.
I’m guess that this different way of cutting stringers:
1. made for a tighter joint between the finished treads and finished risers
2. a stronger stair since more meat was left on the underside of the stringer.
Any ideas on how they did that? Thanks!
Replies
I always cut my rough in stringers that way. I leave about 6" of solid throat, layout my points on the 6" line with a calculator. The flat spot on the front isn't a problem since nothing bears out there.
So you pop a line six inches in from the edge of your stringer?
Then what?
I'm used to using stair gauges/buttons on a framing square to lay out for the tread and riser cuts.
I don't snap a line, I take a scrap and make a scribe stick. If you snap a line a crown would throw you off. I layout the points on the line. Find what the diagnal is, says its 11 7/8", then step them off down your line with a calculator, (I like a construction master). Set your angle on your square with your buttons only use your layout on your line. Usually you'll have about an 1" or so flat spot on the top or your carriage.
Good luck!
Allen, I'm curious...what is the big advantage of having a 6" snapline (scribeline or whatever), rather than simply cutting out the rise and run and leaving the 51/2" that is usually left there. Is that 1/2" or 3/4" that important or is there some other advantage?
If there isn't any other advantage, I see the whole exercise as a giant waste of time that falls into the category of "just because you can, doesn't mean you should".
blueIf you want to read a fancy personal signature... go read someone else's post.
I did a little CAD exercise, and it is attached.
I figured a 14-rise stair, single run, floor to floor, with a 2x10 floor frame sitting atop an 8/0 nominal wall framed with precut (92-5/8") studs.
The pic shows the "knocked off tooth" arrangement gotten by adhering to the "uncut 6-inch stringer" rule.
It shows a 2x12 tread and a 1x riser. It just as well could have shown a 5/4 bullnosed tread.
Provided care is taken in fixing risers so they flush up to tread bottoms, this stair is stiffer than one made by cutting to full points.
I'll have to go back to some text references to say how much stiffer. I cannot recall whether stiffness correlates directly to the square or cube of depth.
But I would say this stairbuilding method has credibility.
By the way, I always do the math to find out that "point to point" dimension, but I never step it off. I figure out where they all are from a zero end of tape, and hold the tape once, and mark 'em off. Stepping can build in accumulated error.
Blue,
The original theory is additional strength. It's become a "thats just the way we do it thing". I honestly don't know if an inch and a half makes much of a difference. The way we build stairs the throat could be 8 " but they need temporary treads. One thing I know for sure is laying out your points mathamaticaly is the most accurate way to go espesially if you need to locate a notch at the bottom.
Allen, I used to be somewhat enamored with the idea of laying out a stringer mathematically. I think I stopped doing that somewhere around 1990. It took a few years before I burned all of my router patterns...I still warmly remember that equisitly freeing day!
I guess everyone has their favorite ways of doing things, but I wouldn't recomend this to any rough framer. This falls into that category of.."it looks wrong" because of the gap. Additionally, it increases the chance that the headroom might be uncomfortably tight, yet meet the minimum code (you might be surprised at how oftn a tight headroom situation comes up...even in big homes.).
Here's my instructions to the kids....err apprentices: If strength is an issue, double the stringers carrying capacity by laminating (sistering) a 2x6 underneath...which normally fits perfectly. If accuracy is an issue, create and use a "speed pattern" which I make out of a corner of plywood in about 30 seconds. It will create an accurate layout that would rival your diagonal method...unless a rookie is doing the job.
Incidently, we do employ notches in approximately 75% of our stringers. The notch accuracy question has never been an issue. If it suddenly became a concern because of questionable layout techniques, I'd force the issue on using my "speed patter" plywood technique and/or insist on a direct measurement between the top nosing edge and the top edge of the landing. By keeping that dimension accurate on the final rise...it would render all the accumulated errors moot.
Personally, I use the accumulated error as a tool to teach accurate layout techniques. If accumulated errors do occur, we start looking for the root cause.
blueIf you want to read a fancy personal signature... go read someone else's post.
blue - "Here's my instructions to the kids....err apprentices: If strength is an issue, double the stringers carrying capacity by laminating (sistering) a 2x6 underneath...which normally fits perfectly."
If strenght is an issue why would you sister a 2x6 underneath rather than just cutting an additional stringer for the stair and using it down the center which is virtually right on the walk line as I mentioned above? You also get the added benefit that the center stringer saves you on labor later on in that you now already have a stringer in place that you can faster drywall or lathe to on the underside of the stair to finish it off.
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Actually Jerrald, adding the center stringer is mandatory on most 2nd story stair systems because they will receive drywall on the underside and drywall won't span 36", the minimum width of most stairwells.
I'm searching my memory banks for instance where stringer strength is an issue...about the only situation that I can come up with is exterior application where there is no under stringer wall or support.
In residential houses, the basement stairs are always framed in and drywalled. We install the wall studs in such a way that they carry the stringer. The second story stairs always have a supporting wall under them. That is precisely why I questioned the need for stronger stringers and more "meat". I've built a few hundred sets of stringer out of 2x10 and cannot remember any strength issues.
Personally, I don't like cutting three stringers, when I know two will suffice. I've often substituted a center framing member (a ceiling joist), rather than cutting that third stringer. I suppose you could make a case that the center stringer will keep the stairs standing for an extra fifty years, but I think my method will keep the stairs functioning for a couple of hundred anyways....I'm not trying to build a set that will out last the useful life of the house itself.
blueIf you want to read a fancy personal signature... go read someone else's post.
blue - "Actually Jerrald, adding the center stringer is mandatory on most 2nd story stair systems because they will receive drywall on the underside and drywall won't span 36", the minimum width of most stairwells."
Exactly, so that's sort of been one of my points. The thing I often see though is builders furring out the center of a stair after the installation to support the drywall and it's just not as efficient (or as strong a stair) doing it after the fact.
"I'm searching my memory banks for instance where stringer strength is an issue...about the only situation that I can come up with is exterior application where there is no under stringer wall or support."
Likewise I think all this talk to get extra throat depth and the resulting strength is a lot of wasted effort. Most stairs, interior at least, run along at least one wall and usually are framed as closets underneath so that supports the other stringer. There is one stair we did a while ago that came down from the center of a balcony with no support underneath and while it had three stringers to keep it from flexing or bouncing at all since it had glass in the balustrade we just ran some steel along on the insides of the outside stringers. And I think yup you are correct that maybe it might be a problem in and outside application like a deck but even if we did that kind of work we would probable still opt for using a center stringer.
"Personally, I don't like cutting three stringers, when I know two will suffice." Well yeah but it saves the step later on when drywall needs to be attached so it's not really a waste in that respect.
"....I'm not trying to build a set that will out last the useful life of the house itself."
Well we sort of are in some respects. On qualifying installations we will guarantee that our stairs (or the ones we install that we have Arcways sometimes produce) will never ever squeak. It may have been a mistake in saying that because since we started that a few years ago I began to always notice how the stairs in my own home squeak and it drives me nuts. (I/we didn't build them that's for sure).
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We seem to agree on most points.
The third stringer is another squeak possibility. That is one reason that tend to want to eliminate it.
blueIf you want to read a fancy personal signature... go read someone else's post.
True, true, real good point, it does provide 33% more points for possible squeaks to develop but squeaks are due to treads that have worked their way loose either through shrinking or flexing. The third stringer should take care of the flexing and we also seal the undersides of all our stairs and moisture/climate control being in place at the time of installation is also one of our warrantee requirements.
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I think its a toss up.
The third stringer might shrink differently...i've seen them remain high, while one or the other end stringers drop....
They would elmiminate some sagging in the middle.
It would be an interesting experiment.
blueIf you want to read a fancy personal signature... go read someone else's post.
I'll never again use sawn lumber for stringers. Strictly LVLs or LSL material for me.
Overkill
blueIf you want to read a fancy personal signature... go read someone else's post.
Howdie to you all,
WOW!!! I didn't know that I was opening a can of worms.
Thanks for all of your input. I would think that just screwing a 2 X 2 to the edge of the "rough" stringer material and using a framing square with gauges would give you the "no points" design I was originally asking about.
Using a construction master calculator to find the diagonal between the "inside points" is one method I had not thought of. My paradigm was shifted.
The finish skirts were cut or routed out with a 10 inch run b/c the treads were 11 1/4" deep. The bottoms of the risers were rabbetted to accept the back of the tread. Also, a piece of scotia was nailed between the tread and the riser
Supposedly, the riser and the tread were hand nailed together with some kind of (rarely heard of) nail.
Any idea of what that nail was?
How do you guys fasten your finished treads and risers to the stringers and skirts?
And of course, plenty of glue and construction adhesive was used too (PL?)
You must have a supply of well-KDd 2x10s and 2x12s that are straight, tight-grained, not split anywhere, and relatively free of knots, for picking out stair carriage stock.
I don't. Not unless I want to spring for clear doug fir at about the price of birch trim lumber.
Up through 2x8 in size, I can get the good Austrian framing #2 SPF, but all the 2x10 and larger stock carried here, is crap from the Canadian mills.
Look, we all know the 2x framing lumber shrinks after we build those homes. Tell me no one has ever experienced a drywall screw pop on a house you framed.
Look at the shrinkage half the width of a 2x4 can do to cause a mud-and-screw bulge in a wall. Now multiply that shrinkage by three or four for how much a 2x10 or 2x12 stair carriage can want to move, away from your tread or riser.
That is why I began to use Trus Joist's 1-1/4" thickness laminated strand lumber stock for stair stringers. And if the yard cannot get that, we'll use LVL.
We do have very good supplies of all dimension lumber.
I have issues with nailing into the edgegrain of lvls and osb.
If I had poor quality dimension lumber, I might rethink my techniques.
Shrinkage hasn't been a factor except in one case where I used 2/12's for risers on a circular stair. We don't do that anymore even though it worked great while it was wet.
blueIf you want to read a fancy personal signature... go read someone else's post.
blue - '....2/12's for risers on a circular stair."
Huh? For risers? On a circular stair. What are you doing there? I don't get it.
Ya'll do understand that hearing all this using 2x12 and LVLs for stairs is pure heresy for me. Stairs to me are "architectural woodwork" and you don't use framing lumber to build architectural woodwork pieces. I don't know, stairs are like cabinetry and ya don't build cabinets (at least not typically) out of framing lumber. To me(us) 2x12s and LVLs are for holding the stairs up. You use them to build the floors and balconys that the stairs connect.
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Jerrald, I was hanging the extra 4 inches down and laminating a 2x4 ledger to carry the tread.
It worked great...was strong, fast...but the shrinkage of the 2x12 hem fir came back to haunt us.
We've avoided that situation since.
I do remember using 2x10 doug fir in much the same manner and never had any issues.
blueIf you want to read a fancy personal signature... go read someone else's post.
But Jerrald, your work is at a completely different level, where houses have maid's quarters and butler pantries. Slate roofs. Exotic species used in staircases, balustrades, even flooring. Carriage houses. Iron gates.
You are in Westchester County, arguably the wealthiest in the state. I am in Essex, perhaps the poorest. It is deer season now, and most are hunting for the meat, not for the sport.
Rustic is our middle name here, and at the highest end of homebuilding, and it is all vacation homes for folks with area codes like 212 and 609, curved staircases are simply not done. Most are done with 14" diameter halved pine logs for stringers and treads.
I don't know where I would have to go to find a stairmaker who would build me a curved one, but I can get good straight ones built with housed stringers, and wedged and glued treads and risers. It is less expensive, though, for us to build them with notched carriages, spaced in from the wall finish, to accommodate full-board skirts, against which we fit, at the end of the trimout, the finish hardwood treads and risers. That's when the stairtool gage comes in handy.
Yes, we had good 2 X 12 SYP (I think SYP) stock to cut "rough stringers."
I like the idea of cutting them out of an engineered product. Nailing shouldn't be a problem because the glue and construction adhesive is what is really holding it together and hopefully keeping it from squeaking.
To Jerald, your work sounds like it is in a class by itself. Of course, having the customers,mmm... clientele, well heeled enough to afford such things would be nice.
Around here, southwestern Illinois near St. Louis, $300K on up will get you one of those McMansions.
Let me digress a little.... a few months back the girlfriend and I were on a walk and stopped by a McMansion subdivision. We checked out a house priced near the half mill mark and it had formica countertops.
I could not believe it. $500K and formica countertops. WOW! I guess it's like a lot like other things, you're paying more and getting less. I could go on about the other shortcuts and stupid things I've seen in new houses but that would be a whole new thread, if not a website by itself.
But then again, most people are too lazy or too trustworthy of the contractor to educate themselves on how the largest investment of their lives should be constructed. It's all window dressing.
I would rather have 1/10th the house on 10 times the land.
To Bob Dylan, how is that stair tool to use? Is it just used for stairs "housed" on both sides?
Bob Dylan - "But Jerrald, your work is at a completely different level, where houses have maid's quarters and butler pantries. Slate roofs. Exotic species used in staircases, balustrades, even flooring. Carriage houses. Iron gates. You are in Westchester County, arguably the wealthiest in the state. I am in Essex, perhaps the poorest. It is deer season now, and most are hunting for the meat, not for the sport."
I understand that but I think you are missing the points I was making in msg #49051.12 and a couple of posts here. It is my contention that building a staircase out of clear 5/4 white pine carriages (stringer) is cheaper or the same total cost (lab & matls) as the staircase built using 2x12 or LVL when the whole thing is complete. The 5/4 white pine carriage is a piece of finished wood workwork. The 2x12 or LVl stair still needs to be finished!!!! You may have saved a few bucks on materials but you've added on a lot of bucks in additional labor now to finish the stair and the labor costs more than difference in material costs.
I mean what all this talk about building a stair and then adding on a skirt board after the stair is installed? Skirtboard? That additional materials and additional labor! Plan and build the stair correctly in the first place with housed stringers instead of sawtooth stringers!
How do you finish off the exposed edges of the LVL carriages where they are seen? If the carriage was out of 5/4 white pine it would have a finished edge.
Are you folks using 2x12 carriages mitering the risers on your stairs to the carriage? It's easier to put the 45 on a piece of 5/4 pine than it is to cut it in a 1-12" thick 2x12. Plus tom have those miters work with a minimum of finishing (meaning no putty) you need to have a perfectly planed flat 2x12 which is very hard to find. You buy 5/4 white pine and it comes perfectly flat. Its a finish board, not rough framing lumber.
Which brings to mind a story. About five years ago I was doing a stair installation for a builder and one of the exposed carriages somehow somewhere got damaged in transit. I told him it was a tricky but I could pull off the stringer and attach a new one. I just need a 8' piece of 5/4x12. He said he'd get it for me. He would have it FedExed to me from the mill he was using for material from upstate in the Adirondacks (Saranac Lake I think). The damn piece of wood, even being FedExed, was cheaper that I could get it from my yard plus he saved on the cost of paying me to pick it up. Smart builder huh? He's a multimillionaire. The most successful builder I know. I've learned a lot from him about how to think lean.
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Jerrald, I'll bet that those of us discussing stairbuilding and making them with site-cut notched stringers, are talking about stairs that run up with gypboard wall finishes on both sides.
That is what kind I have been talking about, and building.
Carriage sets are built with 5/4 or 2x continuous cleats on the outboard bottom edge of the outer stringers, and fastened into place inside the two adjacent framed studwalls. The 1-1/4" or 1/1-2" spacer allows drywall to fit down to it, then an un-notched skirtboard finish, and finish treads and risers are fit to the carriages, so ends are tight to the skirts.
Since the carriage sets go up at the time of rough framing, they are capped with 2x sawn lumber temporary ("construction") treads to serve workers during mechanical rough ins, insulation, and drywall sequences, and at the end of trimout, the temps come off and the finish goes on.
When you are only doing shop-built housed stringer stairs, what do you do about temporary stairs? I am presuming you only can put in the finished ones after drywall and mud work are done.
Bob Dylan - "When you are only doing shop-built housed stringer stairs, what do you do about temporary stairs? I am presuming you only can put in the finished ones after drywall and mud work are done."
Over the years we often get asked to finish stair that were put in by framers and what we always did for the jobs we won was convince them to tear out the rough stairs entirely and we would replace them with our stairs. Well we wouldn't exactly tear them out, we would remove them and save the stringers. We used them many times over. So what if the top and bottom steps are off by an 1-1/2", it's a temporary work stair.
We also build a closed carriage stair using cleats (we use those Simpson TAZ Staircase Angles attached with screws so we can use them over and over again and the are also handy for putting together the temporary staging we need at times too). No miters. Takes an hour at best if that.
And even then a framer can have a apprentice or helper cobble together a set of disposable work stairs (that aren't necessarily suitable or accurate enough for finish work) quickly enough. Geze ya can even buy precut carriages in most of the big boxes too. Ya build the treads from all the 2x cutoffs.
"I am presuming you only can put in the finished ones after drywall and mud work are done. "
Well it depends but depending upon the base trim being used on the project it might be best to install before the drywall so that the surfaces line up and register correctly. If you install after drywall ya don't want to end up butting a 1x6 base board (3/4") to the 5/4 (1-1/8")thick trim board on the stair. Admittedly here in the more expensive home the base molding is often 1-1/8 thick so that it can accommodate some interesting cap molds. You don't install 5/4 boards though for the base you install a rip of 1/4 ply or whatever works as a ground then regular 1x.
Plus we always install protection for the stairs anyway. Corrugated cardboard skirts and treads-riser folds and then a 1/4" masonite treads tacked with brads to hold that all in place.
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Thanks for the info.
The attached pic is a CAD rendering of our next stair project. From the basement on up to the second, it consists of six runs, with each set of three having two intermediate landings.
Finish is clear red birch treads, maple risers and skirts, a 3/4 x 1-1/4 cherry cap, laying flatways atop the skirts.
Here is a photo of the stairs, taken in the house we are replicating.
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Except for the run going up adjacent the bookcase, all the others are about 43" wide, thus the use of 4 stringers shown in the CAD pic.
So, you would do all these with 5/4 housed side stringers? Treads and risers wedged and glued? No intermediate stringers?
Your inputs are appreciated.
Nice stairs.
I wouldn't do any of them...that's all finish work. I don't do finish work.
blueIf you want to read a fancy personal signature... go read someone else's post.
Another thought on the "strength" issue. One stair co. I've worked for occasionally doesn't use any carriages in the middle of their stairs. They rely on the secure fastening of the riser to the back of the tread. I used screws when I did this. I was sceptical at first but after I did a few I was amazed at how strong they where. The tread had a 1 degree bevel at the back and made a nice tight fit against the riser.
Allen, we don't screw them, but we do glue and staple them. It seems plenty strong enough to me.
Of course, I don't mind 1/2"osb on 24" centers either.
blueIf you want to read a fancy personal signature... go read someone else's post.
I have been cutting stairs for quite some time too- I like Blues plywood corner trick too, it works well. Especially if you don't have any trammel points. I wanted to ask all of you, how do you cut your second and third ( if you use three ) stringers. I used to lay out all of them, but have found that scribing, very carefully, has given me better results. I lay out the first one on the prettiest piece of wood and scribe #2 & so on. I seem to get a better match. What say you?
Like you, I cut one, and then use it to scribe the others for cutting.
But, before I scribe and cut others, I test the fit of the pattern, in place.
Amen to test fitting!! Thank you for the reply. RZ
Edited 10/27/2004 8:25 pm ET by robzan
I never test fit.
blueIf you want to read a fancy personal signature... go read someone else's post.
" I never test fit " LOL!! you are goood!
I should add Rob, that sometimes...the stringers fall into the basement!
I still don't test fit the next set though....I cut one, then make three, then bring them over and install....if they don't fall into the basement, I know that I've done a good job!
blueIf you want to read a fancy personal signature... go read someone else's post.
LOL!! that is goood all right- I think i have tried that method a couple times.....
Robzan, I use the same scribe method...basically, I'm just using the first one as a pattern....if there is a slight difference in one unit, it will be the same on the next.
One trick I learned is to stand the patten up on edge on the saw horses. that automatically corrects any crown issues.
blueIf you want to read a fancy personal signature... go read someone else's post.
sorry to bring back an old thread but it occured to me yesterday that the main reason I layout rough carriages with the math method is when I do the finish I like to wedge off the back of the carriage against the finish riser board to create a tight bond between the riser and the tread. The finish stringers are always layed out on the numbers and if they are the same I get a half inch gap between every tread/riser and it makes a squeakless stair. You can still do all this with out the math method but to acheive that kind of accuracy you have to really know your square and step down your carriage exactly the same each cut.
Edited 11/14/2004 10:25 am ET by ALLENSCHELL2
Edited 11/14/2004 10:27 am ET by ALLENSCHELL2
Allen it sounds like your using a two piece stringer system that we never use here.
I'm guessing the half inch gap is created for carpeting to fill.
I've used your mathematical layout method too, in my earlier days, but I just don't do it anymore....I find my corner plywood method to be quite accurate. If I was going to trim the house out, I might save my little template, but I really don't think it's too hard to reduplicate it. I suspect trimmers might have a little trouble getting a finish stringer to fit a rough stringer simply because they don't know the exact number that the rougher used. By the time the finisher gets to the job, the treads are in different shrinkage stages, slightly warped and dipping up or down and it's difficult to determine the precise rise and run.
Just a theory....
blueWarning! Be cautious when taking any framing advice from me. Although I have a lifetime of framing experience, all of it is considered bottom of the barrel by Gabe. I am not to be counted amongst the worst of the worst. If you want real framing information...don't listen to me..just ask Gabe!
Blue, the half inch gap is between the back of riser board and the carriage where I tap in a glued up wedge that smashes the riser against the tread.
I understand now Allen. You are talking about a closed stringer which is routed/housed/plowed.
We don't use those anymore. We cut an open stringer, then laminate a closed "finish rough stringer". Typically we use 2x10 open stringer and a 2x12 laminate. It is strong and fast.
blueWarning! Be cautious when taking any framing advice from me. Although I have a lifetime of framing experience, all of it is considered bottom of the barrel by Gabe. I am not to be counted amongst the worst of the worst. If you want real framing information...don't listen to me..just ask Gabe!
Can you explain in more detail? Are we talking here about sawtooth-sawn carriages? And finish treads and risers that are glued and nailed directly atop?
See the attached pic. Where does the wedging take place? Can you do the wedging if the bottoms of the carriages are already finished with gypboard?
I hope this works, I tried to draw in the wedges..
keep in mind there is a gap of about a half inch between the carriage and the tread/riser, thats where the wedge goes.
Edited 11/14/2004 1:26 pm ET by ALLENSCHELL2
Gene, here's a better pic, I think.........
I find the technique very informative,
I like to use toothless stringers, install brackets for the tread support aspect,and can scrap in backers for risers I still need the religious excercise of the mathematics to determine # of stairs and to find the riser,tread combo, even though I have that in a book...
I usually lay out on the floor in chalk lines and crayon too...Scribe once, cut once!
if I understand this right - how about just adding a 1" piece of wood to the edge of your your stringer to lay out your square against? take it off when your done (screws or small nails).
God I love this forum!
Every time I come in here I learn something new and today was no exception!
I've been cutting stairs the same way for 20 years, and now, starting tomorrow, I'm going to be doing it "better"
Thanks guys. Mark
LIVE AND LEARN
Okay Chills, I'm all confused here. I don't understand the question and we are a stair (& railing) shop! Re: "the installation guys had a way of cutting the rough stringers out of 2 X 12 material so that there weren't any points". What does "there weren't any points" mean?
And beyond that we don't cut any of our stringers out of 2 x 12 material. We cut them out of 5/4 and I never think of or refer to them as the "rough stringer" because in my mind they are "finish stringers" although we never refer to them using the word "finish" either. To me "rough stingers" are the type of stinger done by framers for site built stairs not the stairs built in a stair shop.
Further confusion but I think I figured out what you meant here. "The treads for our straight stairs were always 11 1/4" wide." I'm pretty sure what you are calling "wide" is what we call "deep". Stairs have to be at least 3' "wide" by code.
"So I would cut the finish skirt boards with a 10" run." Skirt boards are installed on site built rough stairs and never (or at least very very rarely) on shop built stairs so that has be confused on what your asking about too. Because if the stair was made with a 11-1/4" deep tread and had a 3/4" thick riser then the run cut on a skirt board would either be 11-1/4" (with the riser butting to the back of the tread) or 10-1/2" (if the riser board was sitting on top of the tread) but it wouldn't be 10".
So I'm guess I'm not really understanding the question and reading the responses you've already gotten on this hasn't helped clear things up for me yet either.
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Edited 10/21/2004 10:29 pm ET by Jerrald Hayes
Okay "Points", now I get it! (thanks to Bob Dylans sk and description). Ya all are trying to get the maximum possible strength against deflection out of the stringer by keeping its throat as deep/thick as possible.
Still I'm thinking we would never do something like that in that for a client who doesn't understand anything about engineering. It would just look like a short-cut was taken or possibly poorly planned sloppy work on the part of the carpenters. Yeah I know technically it's stronger but I think that that's what the uninitiated would think none the less if they are to see the stairs from the underside.
A couple of other more pragmatic and practical reasons why we wouldn't build a stair out of rough 2x12 with "no points" are
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this crude sketch might help.....
If the cut is less deep, then what are you nailing the treads/risers to?
Dryden Construction Services, Inc
"He who xxxxs nuns will later join the church." -The Clash
we use a routed skirtboard so the treads and risers are wedged and glued in the skirtboard rout. The tread only touches the 2x12 carriage at the back off the tread. It's wedged up off carriage. The riser is rabbited out at the bottom and recieves the back of the tread. I usually drive a glued wedge at the back off the rabbit to tighten it against the tread.