[chaz12]

Want to build a set of steps down a hill 12' How do I make the stringer?

[hkstroud]

Tell us a little more about what you are doing. Are you building steps from a deck to a sloping ground or just building steps down a hill side?

[chaz12]

I built a shed over a set of old brick steps on a hill side. The steps will be about 12 ft. longSo in fact I'm building them over a hill side.Sence I can't use the brick steps anymore I will build a set from of treated lumber about 4' away from them.
Thanks
Charlie

[ballengerb1]

OK we undertand what you are doing now. We need two measurements. How far is the drop between the shed and the final ground landing. How long will the stairs run, probably your 12'. Once we have these two measurements we can give you a formula to figure steps and risers and how to cut them. Most home center will carry stringers pre-cut.

[hkstroud]

Measure your run and you rise as shown. Determine tread width. Minimum tread width 9”, most common is 10”. That includes 1” nosing. Let's say you are going to use 2 1x6 deck boards, which are 1” by 5.5”. That's 11” minus 1” nosing. Your tread width is 10”. Divide run by tread width. If possible adjust lower landing to make come out even. If you can't adjust landing, adjust tread width such that run is divisible by tread width. That will be the number of steps.
Divide the rise by the number of steps. The quotient will be the height of the step. That number must be between 6 and 8.25. That will be you tread riser. Maximum tread rise is 8.25”. Minimum tread width 9”. Tread height must be within ¼” of each other. Some variation is allowed at bottom step.

If the number doesn't come out right, you adjust tread width and location of landing, therefore the number of steps, until it does. Might be easier to first divide total rise by a number between 6 and 8.25 (that divides equally), that quotient times the desired tread width will give you location of landing

The total run squared plus the total rise squared equals the square root of the stringer length.

If the stair risers are going to be enclosed, in other words you are going to use a riser board add its thickness to the tread width. If the ends of the treads are going to be enclosed, you nail or screw cleats to the stringer. If the ends are to be open you cut the stringers.

To mark the stringers use a framing square. Place the square on the stringer such that tread width on one leg of the square and the tread height on the other leg aligns with the edge of the stringer. Tool department of Home Depot has little clamps that you can put on square to aid in aligning square. Pay attention to which side of the square you are using, if you are using the inside measurements mark the inside edge of the square. If you are using the outside measurements mark outside of square.

Starting at the bottom, mark the first tread. Extend the tread line completely across the stringer. That will be you cut off line. Mark the next tread, that will be your first step.

When cutting, pay attention to which side of the line you are cutting. It is not unusual to cut one side of the line when cutting the tread and because you are cutting in the opposite direction to cut the other side of the line when cutting the rise.

For cutting the tread width is = tread width – nosing + thickness of riser board if risers are enclosed.

If you want the top step to be flush with shed floor, subtract thickness of tread material from total rise. If you want top step to be one step below shed floor subtract one riser plus thread thickness.

Bob,
Check me close on this, please.

[hkstroud]

Lots of numbers involved. You might want to make a pattern out of plywood before cutting an expensive 2x12. Also figure out how you are going to attach to deck of shed and allow top end cut for that.

[chaz12]

The steps are going to start on the ground at the bottom and end on the ground at the top,stringers are going to be attached to 4x4 posts in the ground.I was going to use 2x8s for everything,is that allright? Trying to keep costs down.I've spent over $500.00 already for a 6x10 shed attached to my garage for my new motercycle.

Charlie

[ballengerb1]

The only way you can get away with a 2x8 is if you do not cut it into a stringer. You could hang your step on a cleat nailed into the 2x8 but you are pushing the limits of the lumber. Stairs are normally designed with a 2x12 because one person caring an object could easily weight 350+ lbs, a 2x8 would start to deflect unless it had additional support along its length, like extra 4x4s along the way set into the ground. Try using this calculator. Stair PanelSet Application Range

[hkstroud]

Well in that case plant your four posts at the top and bottom. Make sure they are square using A squared plus B squared. Add third post each side. Cut and nail up stringers, make sure they are level with each other at several points. Mark location of top and bottom tread. Pick you step tread width and rise. Put square on stringer and mark. . Tread mark should be level and riser should be plumb. The step rise cannot exceed top the stringer edge, the step tread can. Means you have greater nosing. Measure between those two points along edge of stringer. The distance between the top and bottom tread must be divisible equally by that number. Nail up one cleat, use level to locate cleat on opposite stringer. Use square to mark location of remaining treads.

[jon123]

OK we undertand what you are doing now. We need two measurements. How far is the drop between the shed and the final ground landing. How long will the stairs run, probably your 12'. Once we have these two measurements we can give you a formula to figure steps and risers and how to cut them. Most home center will carry stringers pre-cut.

hk,ballenger, I too have a project building an add on platform to the existing box frame of an existing deck approx 8 ft off a sloping ground.. my question is when using temp supports for add on platform ,when measuring, is it top to top.. tape to furthest point on a 2x12, that is from top deck after initial layout.. cut plum top to box frame first and than bottom to top of slab footing on a crowned stringer?. than you can position slab /form to pour level etc. also , which design stringer is best suited using 4 in spaced ballester system.. notched stringers or solid cleated stringer? It's been awhile since I cut stringers but remember how to use the 2 ft sq., usually try getting each rise either 7 or 7.5 x 8.5 in. run for 2x10 tread and adjusting the slab to compremise. For weather snow, I think open rise open tread staircase is better than a closed tread on big staircase(easier to broom /shovel ice/snow) and also I think cut stringers look better (preferred over uncut stringers using block cleats for treads.. think a middle 4x4 support colume/post along each stringer with cross braces underneath for added support on long precut stringers with more than 12 or 13 steps.. what do you guys think?

[jon123]

Lots of numbers involved. You might want to make a pattern out of plywood before cutting an expensive 2x12. Also figure out how you are going to attach to deck of shed and allow top end cut for that.

hk, The deck is off a second floor , I want first to build a platform off the existing box frame using temp supports I plan on using your sketch method for cut stringer (open ends open treads (no board riser) I can put the slab form anywhere so if I were to cut a flush mount angle from top deck for my first 7 rise off x 8.5 sq plum cut tread for a 2x10 tread.. I must notch 8.5 for the rise for a 7 rise using an 1 1/2 tread (2x10) on a three foot wide staircase. Also the 2x10 is actually around 1 1/2 x 9.5 so the run cut should be 8.5 also for the bullnose run.. so the little clamps should be set at 8.5 x 8.5 using a 2x12 which is actually 1 1/2 x 11.5 and so a notched precut stringer will need support even on a 36 inch wide treaded staircase. So my layout for something 8 to 10 ft off the slab can be a standard precut knowing the slab can be positioned wherever the last step rise of 7 inches lands please correct me if I'm missing anything