Does anyone have any advice on forming concrete steps with rounded nosing?
If you're talking about typical concrete stairs without overhanging tread nosings, have always seen the finishers do nosings using hand tool after the concrete is in the forms. A good finisher doing a set of stairs and also the walls on both sides... it's a great thing to watch.
ok, so it sounds like its a matter of finding the right guy, or is there another way to form square edge nosing to get away from the bulky look of a heavy 4" edge, maybe angled risers?
It is DEFINITELY a job for a very good finisher. It is not a DIY thing, and even though I have done a lot of flatwork I would not finish a set of stairs myself. If you find someone who does it every day, you should be happy with the outcome. Angled risers are the norm.
"is there another way to form square edge nosing to get away from the bulky look of a heavy 4 inch edge..."
First off, in a simple (normal) concrete step set-up, you simply round the tread's nose using an edging tool...the riser is slightly angled and the top is rounded...you don't have the nose protruding way out past the riser.
If you intend to have the nose protrude, then you must frame it out accordingly. on walls or even porches ( especially porches that extend out over the wall foundation) we rip strips of wood on a 45 degree angle and attach them to the inside edge at the top of the riser form. This strip produces a chamfer when the forms are removed. It cuts down on the bulky look.
Theorectically, if wanting the nose to protrude past the riser, and be rounded, you could rip PVC pipe of the appropriate diameter and attach it to the top of the riser. To frame in this manner, you would attach an "L" shaped form to the top of your intended riser form...the "L" shape allows the concrete to flow up and over your riser. On the inside of this "L" box, attach the ripped PVC pipe to it using drywall screws.This will give your tread a rounded look.
The key to any concrete pour and how well it turns out is to make sure the concrete consolidates properly...in other words, fill the concrete up slowly, and uniformly, creating no voids which will later honeycomb. Using a vibrator is almost mandatory...otherwise a lot of shovel action and soft pounding on the forms with your hammer will be required...but a vibrator works much, much better.
Key to concrete steps is to have your forms well braced...enough cannot be said about this...one blow-out will definately make you a believer. Knock on wood, I've never had a blow-out, but I've witnessed others who have had this happen...not pretty.
Word of advice...If you don't have much experience with concrete forming and pouring, you should definately hire someone who does to either do the work or inspect your work prior to pouring. This is one time where watching and learning is better than just diving right in.
Good luck with your project.
There are a multitude of ways to form steps depending on the type of steps you are forming. You might provide more information about what you are attempting and then you will probably get a better answer.
In general, I would vibrate all the concrete to make sure it is consolidated near the edges of the forms, let it set up a bit, form your edges, let it set up some more and then pull the forms and work the concrete with whatever tools are appropriate. This could be trowels, brushes, paste, whatever.
It can be as simple as pouring your lower step first and then later pouring the next one up.... until you get to the top, or you can do it all at once if you have some help and are very skilled.