Curved staircase

[Brandon Sistrunk]

I am getting ready to start trimming a house that has an 180 degree curverved staircase. I will admit I have never done a curved staircase. I will have to bend the skirtboards to get them in place. The outside of the case is open. The skirts will be paintgrade. I am not sure what species they want for the treads or the baulisters and handrails. I am looking for good resources on trimming out this curved staircase. I would also appreciate any tips or tricks that can be shared. The bottom step is square no bullnose.

[David DeCristoforo]

Well, there's a first time for everything. But this is not a simple project, there are many ways to approach it and it's going to be difficult to get all the information you need from a thread like this. I would start by getting some really strong coffee and a book like this:

http://www.cambiumbooks.com/books/stairbuilding/0-8069-8101-6/
or this...
http://www.cambiumbooks.com/books/stairbuilding/0-941936-63-5/

Then stay up all night for as many nights as it takes to read it.....

[Richard Wolf]

I will assume the rough staircase has been framed in the house already and this is not a shop built self standing staircase. If that is the case and you are only trimming out the stairs your stringers are not supporting but only to finish the stairs.
Use bendable plywood ripped into strips to laminate the stringers. If you can't get bendable ply, 1/4" ply will most likely work. Only the last layer of the lamination is visible, use 1/4" hardwood for that, poplar if it is paint grade. Hope you have a lot of clamps.
If this is not going to work, take some pictures or include more information and I will try and help you.

Richard

[Cliff Rohrabacher]

without knowing the actual application I submit that Kerfing the inside of the trim boards will allow you to bend them. Take a look inside any guitar. The strips of wood that increase the joint surface between the sides and back and soundboard are kerfed.

A sliding chop saw or RAS would do this best. It'll be some work to put that many kerf cuts across the molding so many feet long as a stair case might be but once done it will let you bend a thick piece of wood.

As an aside all the surface area opened up by the kerfing will substantially increase moisture absorption so if you take such a route it'd be well to paint it before applying it.

[Richard Wolf]

The problem with kerf cutting the stringer boards, and to some extent also using bending ply is, the stringer is not only curved, it is also twisted. If you think you are going to use a material that will only bend in one direction you will have a real fight on your hands. In theory, you should cut the bending ply on a byiss at the angle of the staircase. Depending on how tight the curves are, "most" bendable material will also twist to your needs, but should to be tested.

Richard

[bill mullin]

Just finished one a few weeks ago. It was less than 90 degrees, though. I used 1/4 inch (actually 3/16) poplar ply, 4 laminations.
At 180 degree turn, not sure if this would work. You may have to go to the bending ply.
Lots of clamps for the handrail, at least 2 per riser plus a couple at top and bottom.
I made half my clamps, using 2x4 vertical at junction of tread and riser, screwed thru drywall into framing (before applying finish treads and risers), and 1x4; two 6 in. bolts (one under the rail, one over the rail), clamping the rail between the 2x and 1x.
A little extra time, but saved a lot on clamps.
Used Flex-Trim base cap under skirts.
Hope this helps.

[Jim Kountz]

Man its jobs like this that make me go bbbbbbbbllllllllllllllllpppppppppppppffffffft. Thats about what my brain is saying to me when I think about it. Ive only done a couple of these in my lifetime and will not even try to sound like an expert. Richard is the go to guy here for stairs, looks like Bill has them down pretty well too!! Good luck with it and let us know how it turns out!!

[Brandon Sistrunk]

I am going by the house today, and I will take some photos. The case is already framed, and I will only be trimming out. I am still unsure of the materials the customer wants to use. I appreciate all of your help, and any other resources you know of. Richard, your work is really nice, have you thought of writing a book on stairs?

[Larry Edgerton]

I use this jig to laminate stair parts. I used to do it vertically but found horizontal to be easier when working alone. I intended on making an adjustable one but then work dried up. I love the challange of circular stairs. I have the books David recommended, good choices, and I would add "A treatise on circular work in carpentry"

Mr Wolf does this solely for a living, and I too bow to his experiance.

[Richard Wolf]

Thank you all for the compliments. I just stumbled into this over twenty years ago and it turn out to be a great niche. After twenty years you better be good or you will starve to death.
Nice idea Larry with the horizontal work. Someone used to make a commercially availble adjustable jig, very expensive. Have you thought of using a vacuum bag, sure saves on a lot of clamps.
Bill, nice work on the staircases.
Brandon, yes, send pictures, will always love to see pics. and it makes it easier to understand where problems may be.

I have put my website in my signature line, I don't think that is a violation.

Richard

[Larry Edgerton]

. After twenty years you better be good or you will starve to death.
Nice idea Larry with the horizontal work. Someone used to make a commercially availble adjustable jig, very expensive. Have you thought of using a vacuum bag, sure saves on a lot of clamps.

Richard

Richard, in my rural area it is hard to be specialized. I have done everything from horse stalls to fine furniture to make sure there is food on the table, so my tool selection is all over the map. I have been wanting to try it, but there is no one around here to learn from, so I have not jumped.

I do have a new large medical grade vacuum pump, and a vacuum controller out of a factory, but that is as far as I have gotten. I would love to have a better way on round/spiral work, clamps are a pain. I will get ahold of you if I get another round project and pick your brain.

I just sold my commercial building and so will be moving/building a new shop, and that is one of the things I want to play with once I have ZERO PAYMENTS! I figured my client base is shrinking with the shrinking of the auto industry, so it was time I downsized myself. I'm looking forward to the low overhead.

[Brandon Sistrunk]

Guys here are those pics, sorry it took so long. I will be starting on the stairs Monday. Wish me well. After talking with Richard privately I will need it.

[Richard Wolf]

What makes this staircase such a difficult stairs to trim out and ultimately
build a railing for, is that the pitch of the stairs changes 4 or 5 times in the total run. Brandon has some other pictures where you can see that the top two treads are one size, than they change to wedge shaped, back to the first size, changing again to wedge treads and back again. Not all staircases are symetrical all the way down, but if I'm building them, I try very hard to keep the pitch at the rail line as uniform as possible.
The good news for Brandon is, he is not doing the rail, they are going with wrought iron, which makes for a much easier job than wood. A wood railing on a staircase like this would require an expert stair man to do a good job. And even then, it may not look very pleasing to the eye with all the pitch changes.

Richard

[Walter Plummer]

First off good luck. Not trying to be smart but have the stairs passed any framing inspection? Sounds like it is not really your responsibility but I`m not sure they would pass code around here. Something you might ask before you put a ton of work into something that might turn into a finger pointing legal mess. Just saying:rolleyes:

[Richard Wolf]

The size of the tread does not have to be the same on every step. Think about landings and winders. The risers must always be within tolerances. It just make trimming them out a nightmare.

Richard

[Brandon Sistrunk]

Guys, just an update. I've got all the skirt boards on and risers, 2 treads left to install on these stairs. I made templetes for all the winder stairs, and it is going great. We are using 3'' wide by 1'' thick tongue and groove pine for the treads. I know about the longevity of pine, but believe me there was no talking the homeowner out of it you know what I mean. I finally said, you want pine, lets install pine. I will post pics we had to get some flex trim to cap the skirtboards. I am having one issue. When I scribe in the winder treads my old Milwaukee jigsaw blade is allowing my blade to flex and causing a front bevel on the tread material. I am having to go back and back bevel on the miter saw. I am looking at possible upgrading jigsaws, has anyone had any experience with this. I am thinking about getting the Bosch JS5, but i don't know if that is the issue.

[bill mullin]

Posting this pic in response to Brandon's request via PM.

[Brandon Sistrunk]

We just got this case trimmed out, it took us just over a week. The stair treads are now being stained and the wrought iron is being installed next week.

The homeowner chose 1'' pine tongue and grove material for the treads. They were built on site. I built the front step, but had the millwork shop who ran the trim, build the first tread. We had to use flex trim to cap the inner and outer skirt board. The wood would not make the bend on the outside skirtboard. This was a very tedious but rewarding project. I am glad it is under my belt, and the best part is that the homeowner is very happy.

[Steve Clardy]

Looking good. :cool:

[Paul Girouard]

I am looking at possible upgrading jigsaws, has anyone had any experience with this. I am thinking about getting the Bosch JS5, but i don't know if that is the issue.



Bosch is the way to go IMO. Festool might be better, I've never used a Festool , to spendy and I've never seen one on a job site either, so maybe only rich hobbyist buy them.


On your treads the "ears" should be mitered and returned into the skirt board , at the back / riser to thread joining area. Thats the proper way to do it. Not just cut off flush as you have done.



Over all it looks OK , the grain matching, or miss matching, really could use some work as well.
At least put mixed grain boards next to mixed grain , straight grain next to straight grain. You have wild grain , mixed , staright all willy nilly-ed to together.

The bottom line is the client is happy , but those couple of things you should take into consideration on future projects. The next "Boss / client " may not be so easy to please.

Good luck on your future projects.

[Brandon Sistrunk]

Paul thanks for the tip, I am looking to improve so I am open for areas of improvement. Anybody else don't hesitate to offer ideas on how I could have done something else to add a more professional touch to the project. I have to be honest, never having done any stairs before, I felt as though I did the best I could. So I do appreciate constructive criticism. Also I do have more pictures if anybody would like. Send me message with your email address and I will be glad to send them to you.

[Richard Wolf]

Overall, the staircase looks good, a curved staircase will do that. I am going to be a little tough on you with my criticism.

1.The starting step is not large enough for a volute.

2.The left side of the staircase doesn't over lap the wall enough, the railing may not die into the wall.

3.The mitered returns should only be 1 1/4" wide and run past the end of the riser.

4.You should have cove molding under the treads on the front and side. The small strips up the side of the risers look amateurish.

5.The stringer boards look terrible. In some spots it is 2" above the treads, and others it is 12" above.

I know you had a poor foundation to start with and a lot of compromises had to be made which the home owner was alright with. In the future it is important to understand where the problem areas are going to be so you can either correct them or cover yourself in advance.

With all that said, I'm sure you learned a lot. If it was easy, everyone would be doing it.

Richard

[Brandon Sistrunk]

Richard, thanks for the tips, I will definetly look at things a little different next time. Would you provide a little more detail on comments 1 and 2 on your last response, I would like to better understand your point.

Thanks,
Brandon

[Richard Wolf]

The bullnose end on the starting step should extend about 11" past the second step to allow room for a volute. It doesn't appear that you have enough room, so how do they plan to start the railing?

They will need a rail on the left side of the staircase, 3 steps. It looks like the rail will not hit the wall to have a clean ending. Those left side treads should overlap that wall corner by about 4".

Like I said, I am being tough on you, but sooner or later, a customer will.

Richard

[Clara Koss]

hate stairs so i never will buy a house with 2 or more floors... but the ones pictured are gorgeous....:D