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I would like some information on how best to make a curved stair case. Information such as, how to cut my stringers, what type of stringer to use, and how to calculate the length of the inside and outside radius and transfer that to my stringer.
HELP!!!!!!!
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Mike J.,
Joseph Fusco
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*Mike,A couple of years ago a talented man named Bob Dick built a semicircular stair on a job I supervised. Check a photo at http://www.bowa.com/photopages/classics/p_contemp8.htm.He laid the stair out on the floor below, drawing a full size picture, including the treads. For stringers, he laid up, in place, layers of 1/4" plywood ripped to 2'. They were glued and stapled together. The last layer was maple (our finish material). Now, traditionally, one erects a form in the shape of the stringer, such as a gang of 2x6 or 8 studs laid out along the curve on the floor, then presses the layers aginst the curved stud wall to get them to take their final shape. I don't think I'd be breaking a confidence to say that Bob found a superior way of doing it--he built a rough stair in the curve shape and built up the stringers right to it. I'll ask if he doesn't want to join us and tell the specifics on this.In this stair, there were 8 layers of 1/4" plywood for stringers. Once they were laid up, a hand planer trimmed the top & bottom to smooth, they were veneered on top & bottom, and Bob fit solid stock treads and risers between the stringers. We plastered the bottom. It's a beautiful stair.Incidentally, Bob drives a Vovlo 240 as a work truck. He showed up one day with *all* the plywood for this project tied to the roof--it was a stack about 10" thick. He said it was around 1200 pounds! I ended up buying that car from him and am still driving it as my family car. It has only 210 thousand miles on it.
*Handsome stair! Handrail construction?
*Mike, Be patient. I think you're going to get all the help you need in this thread, as there are a lot of very knowledgeable people posting in here. Joe Fusco is one of them. Supply him with the information that he has requested ( above ), and he'll come back with lots of good stuff for you to consider. If he's in the mood and has the time, being our resident CAD specialist, he might even crank out a 3-D drawing so you get an advanced peak at your staircase.In the meantime, as I have also constructed the rough framing for several of these circular staircases, let me pass on a few of my thoughts.The first and most important thing that you have to determine is the number of risers that you need to get from the ground floor to the second floor. To do this, you have to determine the total rise from the finished floor on the first level, to the finished floor on the second level.Suppose that the studs of the walls on the first floor are precut 9' studs. The measurement of these studs is 104 5/8". Typical framing adds a single bottom plate and a double top plate, so that the final height of the wall will be 104 /5/8" + 4 1/2" = 9' 1 1/8". You'll probably find however, that if you hook your tape measure on the top of the wall in several places, that in reality, the measurement will be more like 9' 1 1/4", as these measurements tend to "grow a little" as you nail the pieces together. In a similar manner, if the studs are precut for 8' walls, or perhaps 10' walls, the measurement is likely to be 8' 1 1/4" or 10' 1 1/4"To this measurement, you'll have to add the width of the second floor joists, as well as the plywood , or whatever , that is used for the subfloor. Let's assume that the floor joists are TJI's and are 16" in width and that 3/4" tongue and groove plywood is used to cover them, and finally that the precut studs are 104 5/8".This results in a total "rise" of 9' 1 1/4" + 16" + 3/4" = 10' 6". Lets also assume that carpet is going to be added to the treads as well as the second floor level. Make no deduction for this. But at the first level, let's assume that tile will be used and that the tile will be about 3/4" above the rough floor that you are measuring the rise to. Subtract this measurement from the total rise of 10' 6" and what you have is the rise from finish floor to finish floor, or 10' 6" - 3/4" = 10' 5 1/4". This is the measurement that Joe is asking for.A good place to start looking for how many risers that you will need is to assume an "acceptable" riser height of 7 1/2". If you divide 10' 5 1/4" by 7 1/2", you end up with 16.7. What this means is that you roughly need 16 and 3/4 risers at this height, or in reality, 17 risers. So divide 10' 5 1/4 inches by 17 and what you will find is that the riser height, instead of being 7 1/2", should be 7 3/8", a very comfortable riser height by the way.To check this over, multiply 7 3/8" x 17 and you get 10' 5 3/8", just 1/8" of an inch over what you want. When you frame the first step, you can make it 1/8" smaller, or 7 1/4", and then everyone of the next 16 risers will be 7 3/8".You must remember two things when you frame the first step.You ALWAYS have to subtract the thickness of the treads from the first riser height. Let's assume that you are going to cut the treads from 1 1/8" plywood. So instead of making the first riser height 7 1/4", you would have to deduct 1 1/8" from it, which would result in the first rough framed step to be 7 1/4" - 1 1/8" = 6 1/8". BUT, to this you have to add back the thickness of the tile, or 3/4", so as a result, you have to "rough frame" the first step at a height of 6 1/8" + 3/4" = 6 7/8".Rough frame all of the remaining risers at 7 3/8" larger than the first, and you should be good to go. There will always be one more riser than there are stair treads, so if these by some chance were the actual measurenets in your house, there would be 16 treads.My girlfriend has just informed me that my time is up. She wants to play FREECELL, so I'm out of here. Hope this helps. I'll continue to monitor this thread for awhile, but as I say, there is lots of good information that will be coming your way from others, hopefully.
* Ken,
Joseph Fusco View Image
*Mike J,Dougs post is very accurate. Don't try this yourself unless you have lots of time on your hands. That's my best advice.Ed. Williams
*Joe,I know that was a little long winded, but I'm sure you're well aware that, if you mess up on the riser height and/or cutting the first step properly, you're in for a world of hurt. So I attach special importance to this first step, whether it be a standard set of stairs, or circular. In my mind, it's especially important when framing a set of circular stairs, as you can't just quickly cut one straight stringer, and check it out for fit, before you continue. ( of course you could layout a storie pole, but I never do ) Now, can we, ( and others ), continue on to the next step, ( no pun intended ) and see if we can help Mike determine the inside and outside radii for the stairs? He needs to supply us with more information tho, like how much area exists in the location where this set of stairs is to be built. It would be ridiculous for example, for one of us to suggest that the inside radius might be 9' and the outside radius be 13', if he doesn't have that much room in the stair area.
*Ken,Don't get sucked in by Joe......That's what he lives for. Ed. Williams
*Ed, I appreciate your concern. But, not to worry, Joe and I have been banging heads for awhile now, and I'm sure that neither of us lose sleep because of it.I've noticed that the two of you have been doing the same thing in many of the threads lately. That's unfortunate, as we all have a lot to offer. It certainly would behoove all of us to stop ragging on each other as we do, and instead, concentrate on departing information that is helpful to others that read these posts, which certainly is the central purpose of this forum. Granted, that would require Joe to stop playing the role of God, but anything is possible.In the meantime, what ever happened to Mike J. who started this thread?
* Ed,
Joseph Fusco View Image
* Ken,
Joseph Fusco View Image
*Apparently.
*Ken,Thank you.I"LL try not to let Joe suck me down to his level anymore either. I quess I just don't find his down loaded algebraic equations that helpful nor am I impressed by his CAD software. I also find his personl attacks to good men like you and me from his keyboard cowardly. But I digress......Your post on tread height would be helpful to anyone constructing any staircase - curved or straight. That's usable information. All I could add to Mike J's question would be to tell he will have to build the layed up stringer material to a radius wall form built from 2x4s on close centers. We use 7" to 12" centers depending on how tight the turn is. This form is then removed after all the 1/4" plywood has been layed up, glued and screwed together, and the sub-treads and risers have been installed. I would suggest that the free standing stringers should be no less than 1 1/2" thick each. That's six layers of 1/4" plywood for each. Lots of time involved. We then add a plywood triangluar gussett to each inside stringer at each tread to hold the sub-tread and riser to the stringers. After all this dries, then we can remove the interior form.There are as many different ways to approach such a project as there are carpenters. Not knowing what the finished product is going to look like makes it hard to give good advice. If the stair has open risers and the treads are say 5/4 oak plank, then it becomes a whole other animal.Maybe we'll get to hear from Mike J again.Ed. Williams
*Maybe I already asked this, but how do you go about building a Code-compliant handrail?
*About the handrails:I've seen handrails made up the same way the stringers are made.Strips of oak (or whatever) under 1/4" thick were laminated and clamped using epoxy adhesive. (many clamps, maybe one every 5 or 6 inches) The handrail had been rougly formed to its final shape before being ripped into strips. It was of course formed much wider than it would eventually be because of the amount of wood lost in the ripping process.After laminating, the railing was routed and finally sanded by hand to achieve the correct profile. You couldn't even see the laminations when it was done.
*Ed,
Joseph FuscoView Image"The price of apathy towards public affairs is to be ruled by evil men." -- Plato
*Ed,I know how you hate this stuff. . . But, I just could not help myself. . .Click Here Ed, it's just for you. . . Joseph FuscoView Image"The price of apathy towards public affairs is to be ruled by evil men." -- Plato
*Mike:It's been a while since I've built a curved stair, but we did a few in a row on a bunch of houses a while back. The first one we did was a stairway sandwiched between two arced walls. This is the easiest. The next few butted a wall on one side, and sat atop a wall on the other. Never got to try anything like in Douglas' photo...Figure the total rise and calculate how many risers you need. Let's use Ken's numbers-- 17 risers. Heed previous advice about risers etc...The tread has to be a particular width in order to comply with code. The standard is about ten inches. With an arced stair, the tread width changes constantly over the length of the tread. You need for the majority of the tread to be use-able and safe to use. Consult your local code official to get a range of suitable sizes. For the sake of simplicity, let's figure that you need the outside of the tread to be roughly 13" tapering into the center of the stair. So the constants are: 17 risers and a radius that will give roughly 13" per tread.The variables are degree of turn and actual radius.If we try 90 degrees turn with 17 risers, (90 divided by 17) we get about 5.3 degrees per tread. scribbling on a piece of paper with a compass, protractor and ruler tells me that in order to get a 13" tread width, I need an outside radius of over ten feet. That seems like a lot of space to give to a staircase.If we divide 17 risers into, say 120 degrees, we get a little over 7 degrees, this yields a radius of about eight and a half feet. Maybe this is a more workable number, maybe not...After you determine what your radius should be, decide how wide the stairs will be. This will depend on the outside radius -- and your local code official I suppose. The inside radius needs to yield a safe tread width. The larger the radius the wider the staircase can be.As I said, the most simple way is to build it sandwiched between two walls. Find the center, square a couple of perpendicular lines from the center, draw your walls on the floor, then draw your treads with a protractor. It'll probably help to do a scale model on paper the night before... Use a dashed line for the back of the tread and solid lines for the overhang (nose). There's your tread template.Now build the walls.Next, rip a 1/4" sheet of ply to two feet widths and tack it to the inside of the outer wall. Plumb up with a level from the dotted lines on your floor template. Those are the risers. Now measure up from the (finished) floor level and mark your future treads. Remove the 1/4" rip and connect the lines with a framing square. There's the first stringer layer for the large radius. (Each layer of stringer will differ slightly since the radius gets smaller by a quarter inch with each additional layer). Glue and nail the first layer to the wall, and glue each successive layer too. For the successive layers of stringer, you can simply tack a two foot rip to the previous stringer and scribe from the back. Clean up your edges with a jigsaw/planer/sander...Do the same thing with the other wall, cut the treads using your tread template, glue, screw and nail...To build an arced stair butting one wall and sitting atop another derive your stringer as above. You can derive the stud heights from your drawing on the floor and your stringer on the wall. It seems to me that we placed a stud at each riser with another right next to it for the previous tread. Make sense? Shorter stud to nail the tread down to and another stud to nail the riser perpendicularly into. No stringer.Feel free to add blocking to tighten things up as you see fit.Like I said, it's been a few years since I've had the pleasure, but I think this is how we did it.Hope this will help,Dan
*Nice pictures Joe,But I think that Mike J. is looking for something more along the lines of the "how to" aspect of building a curved staircase. There's no way anyone could build from those computerized generations of a helix stair. What ever happened to good old fashioned drafting? Ed. Williams
*Ed,
Click the Images Ed so you can get a "BETTER" view. . . Joseph FuscoView Image"The price of apathy towards public affairs is to be ruled by evil men." -- Plato
*Now clicking " Delete from Your New Messages"...
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Joe, did you dampen the drywall to get it to conform to the radius wall in the picture?
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S,
Joseph Fusco
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"The price of apathy towards public affairs is to be ruled by evil men." -- Plato
*Joe,You sure seem to have a fascination with my "Bozo". The women tell me my "Bozo" is quite impressive. Perhaps you are just suffering from "Bozo" envy.I had assumed everyone posting here was 18 or over.Maybe you should turn off your father's computer and finish your homework before bed-time.I have wasted enough time on you.....I will post to you no more.Good bye,Ed. Williams
* Ed,
Joseph Fusco View Image
*Hey, Andrew D. You asked a while back how the rail was done. On this stair, it was built like Ryan said, only it was strips of maple 1/4" x 2", glued with yellow glue (which set too quickly) in place on the metal subrail. Bob Dick, the stairbuilder, correctly figured that the metal would be a little bit different than the stair itself--that is that the steel fabricators wouldn't be able to perfectly follow the stair. So he glued the rail up on the steel, with about fifty clamps and every person on the jobsite. Once it set up he used a router and planer to bring it into the shape he wanted.Bob did tell me that it's a lot easier to build up the rail directly on top of the stringer while the stair is under construction. You can use blocks screwed into the rough stringers to clamp the rail. But the supports for the rail have to follow the stringer exactly and although our steel men did a great job, it wasn't perfect enough.
*Douglas,We used the same process with a cherry hadrail about a year ago. The metal stringers and balistrade were already in place when we got there. The top of the handrail was a 1/2" wide by 1/4" strip of metal which had been welded to the top of the baistrade. The carpenters were able to twist several layers of thin cherry on top of the rail plate, and then glue and clamp 1/4" by 2" strips of cherry to the side to create a rail about 2 1/2" wide. ( I had to buy over 60 6" C clamps to do this.) After the glue process was done, the curved rail was removed and sanded smooth. The homeowner liked the way it looked so much that he had us laminate the straight runs too. It looked great, but it was a lot of work.Ed. Williams
*I'm glad I stumbled on these responses guys. I think this kind of on-site engineering is fascinating. Now, I'm interested in a fairly extreme application, a 6' diameter spiral stair. I've seen article about curved rails, but not spiral -- though the same principles are there. I like the clamp-to-stringer idea, then it would be easy to create a slighter smalled radius spiral if you wanted to hang the rail that way.Were the strips continuous from top to bottom of the stair? How were they cut, by a mill or table saw? Could you have glued up the lamination a section at a time to reduce the # of clamps and glue hassle?... and, the essential question -- how much did this cost?!? i may get a chance to do one of these at some point, who knows?
*anD,I've never done a spiral with that tight of radius, but the method I would use would be the same.The strips are not continuious.....and no, you can't cut down on the number of clamps as far as I know. We milled the strips ourselves on the job from 10/4 rough cherry. We surfaced it in the planer and then ripped the strips and surfaced both sides of the strips. If you don't surface both sides you can not get a good tight glue joint in my opinion.As far as cost? I don't remember. All our work is done T&M. However, no one complained. It was just part of the whole house package. I think the finish sq. ft. cost to trim that particular house was somewhere around $12.00 a sq. ft.Good luck and buy a lot of clamps.(in a pinch you CAN make your own....an old carpenter that I worked with many years ago taught me how).Ed. Williams
*Andrew,If I recall Bob had ours milled off site, but he brings a thickness planer to the job normally so he could have ripped and planed it there if he wished. I agree with Ed that the strips need to be milled on the glue faces. On this stair there are joints in the sections because the strips weren't long enough to run the outside in one piece. I suppose the strips could have been overlapped with offsetting joints to make one long rail but with the yellow glue it was hard enough just getting it into the curve and clamping before it set up. He had to do it in two sections now that I recall, then mark a spot to cut both, then butt join them.Here's a question--what kind of glue has an open time of an hour or so to make this process more workable?Now on a 6' radius, you might be able to use a different rail technique altogether detailed in a book by George R. di Cristina. He calls it "Tangent Handrailing" and it involves calculating the amount of twist in the rail and fabricating sections of solid stock with the proper beginning and end faces to butt exactly. The book is called A Simplified Guide to Custom Stairbuilding and Tangent Handrailing, but you may not find it that simple, at least compared to laminating rails. He does make the point that laminated rail isn't that pretty. Making solid rails on a helix is fairly complex though. This is a wonderful book if you'd like a good, thorough, detailed and well explained look at the math of helical stairs.One last thing. Some rail suppliers make their stock profiles in sets of strips with little tongue and groove type joint between them especially for making custom radius rails. They line up pretty closely and require minimal sanding after glue-up. That would save a lot of work compared to shaping a whole rail after laminating--if you want a stock profile, that is.As for cost, who knows. --Doug "there's a budget on this job?!" Horgan
*Doug,You can use an epoxy with a slow cure hardener. A bit messy but the results are great. Allow a few days to harden before sanding. And keep an eye on the temp.Rick Tuk
*Bla-Bla dittos; I think those guys are hacks, Joe. Always afraid of a challenge. I fear ignorance. The first one of these I did had a plaster finish and turned out awesome. I may put in my two cents if the clowns haven't run him off....JRNicholson
* Douglas,
Joseph Fusco View Image
*Douglas,I might suggest good old Elmers white glue. Plastic resin glue and resorcinol have a limited pot life (they cure real fast). Forget Gorilla glue, it foams when it cures.Ed. Williams
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Joseph FuscoView Image"The price of apathy towards public affairs is to be ruled by evil men." -- Plato
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I would like some information on how best to make a curved stair case. Information such as, how to cut my stringers, what type of stringer to use, and how to calculate the length of the inside and outside radius and transfer that to my stringer.
HELP!!!!!!!