Advice for building a staircase

[Phip]

Hi All, sorry about the long post. I'm going to move my stairs as this will allow me to squeeze in an extra room upstairs. I'm planning to build the new staircase myself from scratch - I realise that buying a kit is the easiest way to do this, but I fancy the challenge and reckon I can do it a) more nicely than the cheap kits, and b) more cheaply than the nice kits. Also, as my house is far from straight and plum I'm not sure they'd fit. I think my woodworking skills are up to the task but I've never done this before, so if anyone has any advice I'd be very grateful.

I'm going for something similar in style to this staircase:

I'm thinking dark wood treads, newel and handrail, and with white painted risers and spindles. Here is a rough mock-up of what the stairs will look like:

There is a stone wall to the left as you climb the first three stairs, and a stud wall to the left once you have turned the corner.

For the treads and newels I'm thinking of using sapele - I've been using it to build some window frames so I have some familiarity with it. I tried dying a bit of scrap with some Liberon "dark Oak" and it came out pretty nice. My current stairs have 20mm thick treads. I was going to replicate this on the new stairs, but this company https://www.pearstairs.co.uk/staircreator/ recommend 32mm treads. Any thoughts?

Any recommendation on what wood to use for the risers? I am thinking of 18mm ply as it's cheaper, more stable, and they will be painted. However I want to do a proper job, so do you think there is a good reason for going solid wood throughout?

Stringers - the treads will be about 800mm across, and the only advice I've been able to find suggested one stringer per 400mm which would mean three stringers are needed. However, all of the standard household stairs I've seen in the UK, including the one I'm replacing, only seem to have 2 stringers. Also, I''m thinking of using 2*12" timber for the stringers, does this sound right, considering that at least one of the stringers will be cut?

My current winder is built with horizontals that have one end in the newel post, and the other set in the stone wall. The new winder will not be in the same place so I can't use the existing holes. My current plan is to do something similar, but using resin fixings to attach the stairs to the stone wall (I'm using resin fixings to attach a ledger plate on the same wall for the new floor so I can do all the fixings at the same time). I've seen that some people build a succession of boxes instead, are there any benefits to either method? In case it makes a difference, the floor beneath the stairs is stone flags laid on earth.

 

[Deleted member 174758]

Advice? Yes, stop reading American web sites on stair building (three stringers? boxes?) - the types of stairs they build in parts of the USA wouldn't meet Building Regs here and in any case, were you aware that staircase replacement, unless like for like, is notifiable works. I'd suggest you go off and read a British book on the subject of stair building, then you'll be able to see what is involved in doing the job safely

20mm is too thin for treads IMHO - sounds like you have a horrible, cheap MDF tread staircase. Most wood staircases use 28, 32 or 38mm treads, although 25mm is sometimes used with hardwoods. Quality staircases are hardwood throughout and cut stringer stairs by their nature need to be solid wood throughout. You can only use plywood risers where the stringers are the fully housed variety, although it can be fairly thin (down to 6 or 8mm) - the edge of plywood will show through however many coats of finish you slip on it and looks shoddy.

Stairs are supported at the top by fixing to the trimmer and at the bottom by fixing to the floor. Any ties through the wall side stringer are only for added stability, not as a primary means of support. My reading g of what you wrote suggests that you seem to think.otherwise

If you've never built a staircase below (and what you said indicates that to be the case) I'd recommend mastering a straight flight before attempting the more technically challenging winder set with one cut stringer and one housed stringer your are seeking to attempt.