It's best to support the head of the stairs independently of the deck frame to avoid overloading an end joist or a rim joist. Here, a single 2x6 is fastened to the 4x4 posts with structural screws and supported by 2x4 jacks fastened to the posts and bearing on top of the footings. The 2x6 is in plane with and provides additional support to the end joist of the deck.
Stair layout starts the same as for cut stringers. Determine the rise--the height from the top of the finish deck to the point on the landing where the bottom step will fall--and the run--the distance from that point back to the deck.
Stringer layout is similar to cut stringers, except that the top of the finish tread is marked, rather than the bottom of the tread, or cut line. Instead of using stair gauges or lining up the framing square by eye, the author screws a 1-by strip of wood to the framing square to mark the tread and riser heights for more accuracy. While laying out the steps, he draws a heavy line for the tread and a light line for the riser. Since the marks aren't cut out and the actual position of the risers will be 3/4 inch behind the stringer nose, the light riser lines can be erased later.
After the primary stringer layout, make a second pass to scribe the bottom lines for the treads using the 1 1/2-inch tongue of the framing square. This lower line is where the top of the tread brackets will be aligned.
To transfer the layout onto the mating stringer, square a line where each of the riser and tread marks meet along the top edge of the pattern stringer.
Then align the pattern stringer with its mate flush across the top edge and transfer the edge marks to the mate.
Face the two stringers so that they mirror one another, then use the framing square to mark the mate with the light riser line and the top-of-tread and bottom-of-tread lines. Positioning the stringers to mirror one another ensures that the same face isn't marked on both stringers.
The top stringer cut is one straight line with the top ear clipped for the decking to pass over. At the bottom, the author cuts both the heel line and the riser line, but the riser-line cut is optional. The stringer can be left to run out onto the landing, but it looks better when it terminates with the nose of the tread.
It's easier and faster installing the hardware when the stringers are resting across a pair of sawhorses, but they can also be screwed in place when the stringers are in position. In either case, orienting the bracket along the line at the bottom of the tread is important: too far forward and the bracket will interfere with the riser installation. On these stairs, the author wanted the tip of the tread nosing to line up with the top of the stringer, so he positioned a section piece of 2x12 at the tread line and measured back 2 1/4 inches along the bottom from the face of the tread: 3/4 inch for the tread nose overhang (code is 3/4 inch-min. and 1 1/4 inches-max. projection) and 1 1/2 inches for the 2x10 riser thickness.
After setting the brackets, the author drills pilot holes for structural screws to be driven through the outside of the stringers and into the end of the treads to help keep the assembly tight.
After positioning a tread between the stringers, the author drives structural screws up through the metal brackets into the treads.
Structural screws driven about a foot apart through the back of the risers and into the back of the treads beef up the assembly.
The front of the treads are screwed down to the structural risers at 12 inches oc.
Five-inch flat-head structural screws are driven through the pilot holes in the stringers and into the treads and risers.
The stringers are fastened to the rim board and header using stair-stringer connectors and structural connector screws.
Bracketed stringers are taller and provide more attachment surface than cut stringers, so they tend to be more stable front to back. To keep posts from moving side to side, the author uses a Fastenmaster-designed Thrulok block-and-screw system, where the 4x4 posts and blocking cut the length of the riser board height are ThruLok'd to the structural riser. Longer ThruLok screws are then driven through the stringer, post, and block.
After notching bottom tread around the 4x4 post, the author screws it into place like the other treads, and finishes up the railing.
