Answer 1: Mostly out of solid oak but I can't see any reason why you can't make the risers out of oak faced ply or even MDF if you wanted to go cheaper if you're trenching the treads and risers into the strings and you're covering the underneath of the stairs. If you're doing a cut staircase however I don't really think there's any way around using solid unless you pinned on mouldings etc... If you haven't thought about newel posts yet, I actually really like the Lathams Woodex 90x90mm Newel posts as there is machining to do on them at all, just trench them, mortice for a handrail and put a cap on top. They're 4 10mmish pieces mitred on the outside so that it looks like 1 single piece of timber for a post and then the inside is filled with offcuts of oak (Although I have come across chipboard in there while trenching before :shock
If I get a chance I'll take a photo of the end of one to show what I mean.
Answer 2: Completely straight flight with no winders/kites? All in one go with the exception of the D-end step if there is one. It's heavy and awkward, simple as that really. You could take the staircase in kit form and assemble it next to the opening if it was easier, then all you have to do is lift it into the hole rather than transport it and trying to carry it into the house, etc.
Answer 3: Not normally, it's usually the painter and decorator job. The absolute best finish job I ever saw was Osmo Polyx Oil, absolutely dead smooth, lovely colour, bombproof. He still won't tell me his secret of applying it though
Once did a job putting a secondary 12 step straight flight staircase above an old one to go into the attic space, all solid oak and seriously heavy. It took 5 of us to get it up the first staircase which had a 90-degree turn in it which luckily had a pretty open landing so we managed to get it there with a bit of grunting. Then it took 3 of us to actually put the stairs in the hole, one on a ladder on the stairs underneath to take most of the weight, one on the landing to lift the bottom end of the stairs and push it along, another up in the attic to take the weight of the staircase off the guy on the ladder and handle it into position.
Looked like a right bunch of cowboys to be honest! :lol: