Half-Wall/Sub-Wall around Spiral Staircase

[Hurley]

Hey Everbody!

I have put a spiral staircase in my house, and now am onto the final touches. I need to close in the staircase, so i'm hoping to build a half wall around it, with a nice hard maple cap, and a gate for entry. I have never built a half-wall before, and am weary about how sturdy it will be on the far end away from the wall, with only the floor joists below holding it. Mostly because it will have gone through 2 angled portions by the time it gets there.
Since I can't attach a pic because of Forum Regulations, you'll have to use your imagination.

Some info = LVL beams underneath and in line with proposed half wall, except for on the 'angled' portion...will need to put in support underneath for that maybe.... floor is 1 7/8ths thick (maple, then 7/8ths pine, then floorboards lol..old house)

Thanks in advance for any advice and knowledge. Can't wait for some replies!

[HayZee518]

once you find where you are going to place it, put lag bolts up through the floor into a four by four plate. if you spot the four by four over a joist lag down through the four by four into the joist. when you construct your wall screw everything together and use construction adhesive.