Make the steps 12 deep by 26 5 wide.
Build two step stairs.
Clamp the stair gauges to the carpenter s square.
Cut a notch in the bottom of the stringers to fit over a piece of 2 x 4 lumber making sure to cut the notch in the same place on each stringer.
Using two treads on each step minimizes the cracking and cupping that might occur with a single wide board.
Learn about an old school technique to mark and cut stairs stringers without any specialty tools or calculators.
I recommend that anyone building a staircase in there home contact a building inspector to inquire about current and applicable fire building code.
This will create a stair stringer calculator.
For each stair cut 10 treads from 2 x 10 lumber and 7 risers from osb sheets.
Build your bottom step twice as wide as a single step.
The simplest way to do this is like a toddlers step stool with 2 steps instead of 1.
Rip 1 x8 risers to width and cut to length flush with the outside of the stringers.
All steps must be the same size the rise and run must be the same on every step width of each step must be at least 2 feet 8 inches normal household steps are.
2 steps at 9 66 leaving 9 66 from the second step to the hot tub.
To make extra strong steps place 2 in 4 in 5 1 cm 10 2 cm boards on both sides of the center stringer under the treads.
Also cut one piece of treated 2 x 4 lumber to 3 long.
29 3 9 66.
You will need one box for each step.
But the basics are generally.
Use the narrow part of the square for clamping the riser gauge and the wider part for the 10 1 4 in.
Lay out the stairs by drawing on the outside of the square sliding the square along until it meets the last mark to learn how to build steps.
Build your top step as you would for a single step.
Double box steps are built using the same techniques as for a single step.
For instance you could cut 1 in 5 in 2 5 cm 12 7 cm boards to the width of the stairs and install two on each step with a gap between them.
Fasten the two frames together with the back framing members flush with each other.