Ok I'll try to explain the proposed process.
I am building a set of stairs that will go up to a quarter landing then from the landing to the second floor.
They will be 36" wide. I have built the landing after reinforcing the floor joists adequately. The landing is 36" x 48", the first set of stairs will sit against the face of the 48" face. The upper set of stairs will sit upon the landing 8 1/2".
My plan is to use 2 pcs. 2 x 12 x 10ft. for the lower set. 1 pcs. 2 x 12 x 12 cut in half for the upper set. I will layout my rise and runs to make a housed stringer. I will router out the pocket, I have done one set before with a circular saw and chisel and made a set with a router. They will look like this when I am done http://www.builderbill-diy-help.com/image-files/housed-string.gif
The pockets will allow for a 2x tread and a poplar wedge. I will make the pockets 3/4" deep.
I will use 2 x 10 x 12 cut to 4 boards 34 1/2" long to make treads. I will use 2 x 8 x 12 to make the risers.
I will cut poplar wedges to match the angle cut on the bottom of the pocket.
I will glue and screw the tread and riser will making sure the stairs are square. I will glue and brad nail the wedges in place.
I will tiling the floor at the bottom of the stairs and this will be 3/4 higher than the sub floor that the stairs sit on. The upstairs will be carpet so I have allowed for the hieght difference. Not sure how I will finish the stairs so I am allowing for 3/4" for hardwood, if I carpet I will build up with plywood to make the rises proper.
I hope I have explained myself well enough for you to understand. I have built these stairs in the past and I really just want to use the best material. I was going to look at the price of LVL but I think I will be using the 2 x's My lumber yard normally has great lumber and I have a good relationship with the yard guys.
Please let me know if you think I am making any mistakes.
I want a solid squeak free house. Thats why I am a bit screwy