CURVED STAIRS

did any of you gentlemen have experiance creating curved stairs? How would one
go about curving a stringer. I guess it would be a built up box beam 5" x 8"
how to though, it's all about how too.
Reply to
CropseyIronWorks
Loading thread data ...
I've seen curved stringers made from lot's of stuff, 1/2" x 12" plate, open channel iron, channel boxed with plate, two channels welded toe to toe, pipe and square tube.
Tube in your 5"x 8" range would be the first thing I would look at.
JTMcC.
Reply to
JTMcC
The tread is made op of a piece of sheet, about 16" on outside end and 3" on inside end with a piece of pipe attached in a vertical position. Both front and back edges are bent with a 1.5" lip to give strength. The piece of pipe acts as a collar to slip on over the verticle pipe the stairs are wound around. Just slide them all on and weld into place when spaced properly.
Clear as mud......right.
Bert Newfoundland
Reply to
Bert and Eileen Plank
What you describe is commonly known as a "spiral stair", and rarely has a stringer. The poster ask about a "curved stair", which is different than a spiral, and almost always has at least two stringers.
JTMcC.
Reply to
JTMcC
This probably doesn't help much, but I witnessed the construction of a grand spiral stairway for a "mansion". It was out of wood, however, the spiral "stringers" were constructed out of thin plywood sheeting. Once the curve and incidence were set to please, layer upon layer was added, glued screwed and clamped, layer by layer until the desired thickness was reached.
I would imagine, similar, pleasing results could be done with steel. Building up the thicknesses to the desired level.
Scott
Reply to
Scott
Curved steel pieces are generally rolled, it's quick and convienient.
JTMcC.
Reply to
JTMcC
You will need some measurements first such as total rise and the radius of the turn as well as the total angle of turn you want. The rise and run on the centerline radius will have to be to code . I use the rule of 75. The product of rise and run should be about 70 to 75 so a 7.5 rise has a ten inch run. If you provide the rolling shop you select with the particulars they will confirm your slope and radius then roll the tube or plate to the shape. A built up box member would be two pieces of eight inch flat bar rollled to the spiral. The caps top and bottom would have to be cut and tacked to the corners of your two sidewalls. If you don't want to do the developments you can erect the two sidewalls with small flat bar spacers to hold them five inches apart. You can then take cardboard and trace the shape from the erected sidewalls of your box. Running a plumb bob off your points down to a circle laid out on teh floor will help to confirm you have the correct radius of turn. We just completed a spiral stair that was over 14 feet tall. We did it horizontally. Interesting experience is all I can say.
Randy.
Reply to
Randy Zimmerman
In the business they are called "sweep" stairs.
Find a local rolling shop to have them formed.
Reply to
Ernie Leimkuhler
Perhaps rolling them is convenient in most cases. However, to roll them on the grand scale I witnessed the carpenter do would have been rather difficult. The curve was huge (18' radius for the outside rail) and tall (for 12' ceiling). It would have taken a semi to haul and it would not have fit through the door. Also, the tread wide was at least 8'.
But, anyway, now I am curious. Is it possible to for a free-form or not-so-spiral staircase to be made out of steel as I described the wooden one? Layer by layer.
Scott
Reply to
Scott
Scott,
Large pieces are rolled routinely, staduim roofs run hundreds of feet in length and consist of hundreds of rolled members. Curving bridges can have rolled sections over 1/4 mile. Long and large curved stairs are pretty common in commercial building and have been for decades. They come in on many semi loads. The many pieses are field welded of course. Chicago Metal advertises the capacity to roll 44"x285lbs. beams the hard way, and 36"x845lbs. beams the easy way. There are companies in every part of the country that roll big iron.
JTMcC.
Reply to
JTMcC
You are correct. I guess I should have mentioned the part about getting it throught the door first. I am sure there are plenty of places that do rolling. The other trick would have been the shape itself. The carpenter did make quite a few adjustments in the shape to make it fit the location best. I am not sure how he would have made the specifications to give to the metal works.
Scott
Reply to
Scott
I've been on many jobs, in existing buildings, where large openings were made in roofs or walls or both, to move big things inside. Seismic retrofits are a classic example. I've also had to saw cut large openings in concrete basement walls to remove old chiller units. It's suprising how many times additional construction doesn't take into account that the chiller will have to be replaced at some point. If they are willing to spend the money required, anything can be put anywhere.
JTMcC.
Reply to
JTMcC
As JT says it can be done if there is money available. A sweeping staircase can be made with rolled stringers that bolt to the floor and to the landing above. All the intermediate stairs as well as the railing could be bolted. Conceivably all the pieces could be carried through a conventional door with four people to carry the steel stringers. There would be no reason to laminate. Just watch a structural steel building go up. All the holes and distances are calculated before the pieces are made. If everyone does their job right a whole project can go up without a single out of position hole. It happens occasionally. Randy
Reply to
Randy Zimmerman
All of the above can be welded as well as bolted. I've seen on historic buildings, where the goal is as little disruption as possible, large amounts of iron hand carried up two or three floors in small pieces. That makes for a whole bunch of extra labor making it back into large pieces, but some buildings you just can't put a hole in the roof. And some very old neighborhoods don't have room for a crane, or won't support one without risking damage to really old underground water pipes, ect.
JTMcC.
Reply to
JTMcC
In what business? There have always been 4 types of stairs, and 4 classes within each type. I've never seen drawing with the term sweep on it. What would the term sweep refer to, circular or curved? And what term would you use for the other? Who changed the classifications and when did they do it?
JTMcC.
Reply to
JTMcC
Can't answer your questions, but the term does seem to be used
formatting link
Not to forget this one, seems you can sweep most anything
formatting link
:-)
Wayne
Reply to
wmbjk
Well I have been in the architectural metal business for 8.5 years, and in the Seattle area everybody knows that a sweep is a curved staircase with no center post.
Sorry if that offends you, but everybody in the Northwest understands the term,including all the union ironworkers and boilermakers I know.
I have never had to explain the term to anybody, and I have never heard anybody but a homeowner call them anything else.
Reply to
Ernie Leimkuhler
I'm definitly not offended by any use of differing terminology, and my Ironworkers apprenticeship manuals are not the current edition, but I've hung quite a few sets of stairs and like i said, there have always been 4 types, and 4 classes. I've never seen anything else on a drawing. If you call a curved stair a sweep, then what term do you use for a circular stair?
JTMcC.
Reply to
JTMcC
If it has a center post then it is a "spiral" stair.
Reply to
Ernie Leimkuhler
Leave straight stairs, and spiral stairs out of it as they are self explanitory terms, how do you differentiate between a curved, and a circular stair? If you use the term sweep for one, what do you call the other?
JTMcC.
Reply to
JTMcC

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.