No doubt, building deck stairs can always be quite a tricky job. However, if you plan it properly and follow a proper sequence then you need not do too many calculations to figure it out whether you are going right or not.
You may get a few wood tutorials from Wood Critique also where you may get a few DIY steps, and by following them you can replace your old stairs sets with new ones. You must have all your necessary carpenter’s tools available with you to start building.
Calculate rise and run
To start with, find the total rise, i.e. the vertical height of your staircase. Then measure down your landing location. With those dimensions, you can calculate the rise of each step.
Now you need to figure out the total run of your staircase that is the total horizontal distance your staircase will cover from your bottom step to the deck. Just multiply your step numbers by each step’s horizontal depth. Your optimum depth for the deck and porch steps will be 10”, which is sufficient space for installing two 2×6 treads.
For building the staircase for any height of deck, you need to break up your staircase with a certain intermediate landing after 7 or 8 steps.
You can mark the tread notches by using a framing square that is fitted with stair gauges. They provide an accurate way and mark several identical notches. Now clamp one stair gauge directly at your rise dimension. Then attach the other gauge with the body of the other square at your run dimension.
Then, start laying the square on your 2 x 12 by using gauges pressed against your board’s edge, and then mark your tread and riser. Slide your square down, and align it with your previously drawn notch, and then draw the next one. Cut the notches by using a portable saw after drawing the entire tread-and-riser notches on your first stringer,.
Now, trim the stringer bottom by an amount that is equal to your tread thickness. As an example, if you are installing 2 x 6 treads, then cut 1½” from the stringer’s bottom. Once you have completed all the cutting of the first stringer, then use it as your template to mark all the remaining stringers. That will ensure each stringer to be of the same size.
After you have set the stringers in their place, lay one long level all across the stringers and confirm that each of the step is leveled. If any high spots are found then pare them down by using a block plane.
Install treads and risers
By using any power miter saw, cut the risers for speed and accuracy. Then fasten each riser to the stringers by using 2½” trim-head decking screws that have tiny heads.
After installing the risers, fasten the treads by using 3” trim-head screws. Now leave a 1/8” – ¼”. space in between the treads. Keep installing treads. The 4×4 posts used for supporting the staircase handrail may often be bolted to stringers before you install the treads.
Finally, apply an exterior-grade finish, for deck stairs, and use acrylic-latex paint to the porches.