Circular stairs: what is your favorite arrangement?

[jimAKAblue]

I'm going to be rough framing a set of circular stairs next week. I have my favorite options and techniques in the hidden chambers of my memory banks and I'll probably choose one of them, based on the available materials onsite...

but...

I was curious about how others approach this task.

The possibilities are many: dimensional treads, dimensional risers; dimensional treads, plywood risers; ply treads, dimensional risers, etc.

And, what do you use to support the treads and rises. What is your radius walls comprised of?

The set I'm building is located over a solid wood deck, so supporting everything will be easy. Here's a drawing of the set I'll be roughing in.

[olllee]

Re: Circular stairs: what is your favorite arrangement?

I would build them in the shop and then install . Do they not spec material? Shop built is always better

[jimAKAblue]

Re: Circular stairs: what is your favorite arrangement?

No, they do not spec the materials. In fact, there is no other details regarding the construction of the circular stairs other than the floor plan. I can order any material I want for the stairs and I'm reasonably sure that they would ship it out, unless I demanded some exotic wood imported from overseas.

So, how would you configure your parts? What would you use? Do you have a favorite system? Have you ever framed one onsite in the field, in the open air (with rain and snow gracing the experience)? If so, what materials were chosen/used?

[Tim Uhler]

Re: Circular stairs: what is your favorite arrangement?

Jim,

If you do build them onsite, I'd use Advantech for the treads. It is crazy stable.

[jimAKAblue]

Re: Circular stairs: what is your favorite arrangement?

Jim,

If you do build them onsite, I'd use Advantech for the treads. It is crazy stable.

Tim, they will be built onsite, sometime late next week (weather is coming in). I'm a fan of Advantech and some of it's competitors.

I'm most interested in how you, and other support the treads. I've done them many different ways and there are pros and cons to each decision.

I'm leaning toward using 2 x 10 risers, with a 2 x ledger glued and screwed on the riser to support the tread.

I'm somewhat concerned about shrinkage on the 2 x 10. I've seen stair systems shrink out of control, resulting in substandard results. I'll make the decision when I see the actual materials that is shipped.

I'm contemplating a laminated system on the riser but I hate doing double duty.

This is a new builder and new lumber supplier so I don't know what the materials will be. I'll be hashing it out with them on Tuesday, weather permitting.

[Ed Michnick]

Re: Circular stairs: what is your favorite arrangement?

No, they do not spec the materials. In fact, there is no other details regarding the construction of the circular stairs other than the floor plan. I can order any material I want for the stairs and I'm reasonably sure that they would ship it out, unless I demanded some exotic wood imported from overseas.

So, how would you configure your parts? What would you use? Do you have a favorite system? Have you ever framed one onsite in the field, in the open air (with rain and snow gracing the experience)? If so, what materials were chosen/used?

There no details in regards to the finished materials? What about tread thickness, finish riser? Railing and balasters? All these will affect your layout and how the stair is built. What about finished flooring material? This will also affect your layout.

As mentioned, a stair like this would be fabed in a shop and installed after the drywall and finished flooring are in. There are a lot of things going on with a switchback stair like that, if your not experienced with stairbuilding it might be best to sub it out to a stair company. Stick with building the basement stairs and stair backs.

[Tim Uhler]

Re: Circular stairs: what is your favorite arrangement?

Jim,

I think I used a 2x12 and 2x4 ledger. Here is the photo gallery of the one I did in 2006 https://plus.google.com/photos/10166...artnerid=gplp0

and a similar one in 2010 https://plus.google.com/photos/10166...artnerid=gplp0

My preference if the $$ is there is to use 1 1/8" LVL rim board instead of 2x12, but the 2x12 doug fir we get is pretty good, especially if I order 12' lengths.

[olllee]

Re: Circular stairs: what is your favorite arrangement?

Ed has it right if you want something that will be around for many years sub it out to a stairbuilder ,it should be in sometime before drywall ,or after depending local traditions but for sure before finished floors as most atair builders build to sub to sub floor and most would like the finish to meet the scribed stringer,risersub floor conection

[Dick Seibert]

Re: Circular stairs: what is your favorite arrangement?

I would add my voice to those who say sub it out to a stair builder, even the best of carpenters can't laminate stringers and skirt-boards on the jobsite, and somebody's got to laminate the rails including the gooseneck that has to be carved.

[jimAKAblue]

Re: Circular stairs: what is your favorite arrangement?

I would add my voice to those who say sub it out to a stair builder, even the best of carpenters can't laminate stringers and skirt-boards on the jobsite, and somebody's got to laminate the rails including the gooseneck that has to be carved.

Dick, I'm not sure that you, Ed and Ollie are understanding that I'm the rough framer on this job and the rough circular stairs are included in the rough frame. I'm not doing skirt boards or rails or the finish treads etc. I'm simply roughing in the circular stairs and it really isn't that big of a challenge. I was just trying to see how other rough framers did theirs. That's why it's posted in the "rough framing" section.

[jimAKAblue]

Re: Circular stairs: what is your favorite arrangement?

Jim,

I think I used a 2x12 and 2x4 ledger. Here is the photo gallery of the one I did in 2006 https://plus.google.com/photos/10166...artnerid=gplp0

and a similar one in 2010 https://plus.google.com/photos/10166...artnerid=gplp0

My preference if the $$ is there is to use 1 1/8" LVL rim board instead of 2x12, but the 2x12 doug fir we get is pretty good, especially if I order 12' lengths.

Tim, there was a set of circular stairs in the second link. I'll probably go with the 2 x 12 riser too if there is any on site. It's a TJI job so dimensional planks might be scarce. We also get pretty good doug fir here, so I'm leaning that way. I gave some thought to the rim joist idea too and I will propose that to the builder.

One difference I immediately noted is that you start your stairs from the top and work your way down. I'll see about doing some pics of my system.

[jimAKAblue]

Re: Circular stairs: what is your favorite arrangement?

There no details in regards to the finished materials? What about tread thickness, finish riser? Railing and balasters? All these will affect your layout and how the stair is built. What about finished flooring material? This will also affect your layout.

As mentioned, a stair like this would be fabed in a shop and installed after the drywall and finished flooring are in. There are a lot of things going on with a switchback stair like that, if your not experienced with stairbuilding it might be best to sub it out to a stair company. Stick with building the basement stairs and stair backs.

I've got no info regarding finished materials. I do know that the finish materials on the stairs will match the height of the finish at the foot and head of the stairs, so no adjustments in the rise is needed.

Regarding your helpful suggestion to let someone else do it if I don't have the experience: How would I ever get the experience if I keep letting someone else do them LOL?

[Tim Uhler]

Re: Circular stairs: what is your favorite arrangement?

Jim,

I started from the top because that is how John Kirkpatrick suggested I do it. I found it easy to keep things plumb this way, and ladder placement was easy. I don't know otherwise.

[jimAKAblue]

Re: Circular stairs: what is your favorite arrangement?

Jim,

I started from the top because that is how John Kirkpatrick suggested I do it. I found it easy to keep things plumb this way, and ladder placement was easy. I don't know otherwise.

Who is John Kirkpatrick?

I've always started at the bottom because I want the luxury of having steps to get to the higher treads and risers, and, to have a place set my saw and nail gun. Depending on technique, there is a slight danger of getting to the top and not having the correct sized tread/riser, so, in some ways, it's much "safer" to start at the top and work down.

[Baldwin]

Re: Circular stairs: what is your favorite arrangement?

Dick, Ed and Ollie have already said a few things. Here's a few more...

As a professional, finish stair builder, my job often begins with a complete demolition of the rough framed stair. As a general rule, nothing the framing carpenter has done is either right or acceptable (and overlaying a rough stair with finished stair materials was never a good idea).

Since (as you've stated) "I've got no info regarding finished materials", your chances of getting it right (in my opinion) are reduced to zero. Matching finish materials on the 1st floor, stairs, landing and 2nd floor (as you've been told) is highly unlikely. Hardwood treads are typically one inch while flooring and tile are 3/8"

I understand your dismissal of all of this (since it's not your job) but that won't do me any favors. Of course it's not your fault, it's the architects' responsibility to provide both rough and finish carpenters with all the details. (They typically don't and when they do, they get it wrong anyway).
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OK, now that that's off my chest, I might offer some more constructive advise or opinions...

Start with a story-pole and get it right. Never let it far from your sight. Verify that the concrete slab or sub-floor, is level. It's not uncommon for a half-inch or more of discrepancy between the location of the first step and the last.

Construct the entire sub-stair from plywood and (preferably) LSL studs. Do not use any construction lumber (2x12's etc.) I use 1 1/8" sub-floor plywood for both the treads and risers. The risers are best ripped clean and straight on a table saw and nailed to the studs. They are then glued and screwed to the back of each tread. A rabbit or dado in the riser receives the back of the tread.

Do not include any overhang or nosing on the tread (since I'll just have to cut them off anyway). Never construct a stair with "kick-back risers" since I'll have to "un-kick" all of them (and attempt to kick your ass afterwards) The tread/riser joint is best glued and screwed (no squeaky nails please) and preferably glue-blocked from underneath.

A typical stair will not require a middle stringer or any other mid-span support. Do not add one since any rough-cut contact with the stair will positively squeak.

Glue is defined here as carpenters wood glue or epoxy and not sub-floor adhesive in the tube.

Omit any round-end starting-step since I'll only have to tear that out as well. There are other considerations but I'm writing a novel here
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It's really too bad that rough and finish carpenters can't get together a little more often since we're both trying to do the best we can.