hardwood-floorstairs
I'm a little confused about the finished floor (at the top of the stairs) and the thickness of the treads. The treads I'm looking at are around an inch thick. The finishing (hardwood, as seen at my local big box store) for the top of the stairs is 3/4" thick at most.
Is it assumed that the top tread nose will be different from the others?
Time = Money. And assembling these in a manner that won't cause you headache later is going to take a lot of time.
To make a tread, you'll need to laminate the floorboard together somehow, otherwise they will flex under the weight. Construction adhesive would work, but wood glue might be better. And don't forget to sand or plane off the finish before you glue them together because the glue won't stick as well to the finished face.
Multiply all of this by the number of steps you have.
Another method with slightly less work is to put down regular stair treads, then put your hardwood planks over the top. You need to carefully select the correct thickness of the tread, taking in to account the thickness of your planks and the nose molding. This is similar to what is described in the article you linked to in your comment.
There are 2 ways to do this, the first way is in essence just cutting the wall at the top of the skirt board and capping it off and setting the handrail on top of the cap that is finishing off the cut wall, sounds a bit crude, but essentially that describes what you will have.
The up side to this is you will not need to do a floor repair, depending on where your wall ends where the newel will be.
The other way to do it is by removing the wall entirely, repairing the floor, removing the treads and risers, and set longer ones with return nosings on either side. and re-support the stairs with a new walls under the existing carriages.
This is the most work, but will give the best result in my opinion.
Jan. 2, 2014 edit
Here is the work I did in 1989 that shows what I did.
This one shows the best example of the effect I was trying to explain. I do not have a shot that shows how the handrail goes past the ceiling, but with a little imagination you could picture what the rail would have to do if the stairs were much wider at the bottom.
Edit #2
I did a little calculating to help, if it may
Best Answer
The top step is not a tread. It's flooring. You buy the stair nose as part of your flooring purchase, not the stairway build. Most manufacturers of hardwood will provide a matching stair nose, but you may have to order it.
Note that the stair nose is a groove. You can also purchase a double-tongue that will slip in that groove converting it to a tongue should you need to.