Creating deck stairs for a wrap-around deck is quite similar to building stairs for a regular deck. The important thing to remember when building a wrap-around deck is that the position of the stairs will need to put in a portion of the deck that won’t stick out like a sore thumb.
Step 1 - Determine Location
The steps will need to be in a location that is centrally located but sort of flushes with the design. Typical wrap-around decks will have access from the house that goes naturally by simply adding a door. Steps stand out a bit more. It might be the best option to install the steps at the point of the deck that is toward the side of the house, not the front.
Step 2 - Measure the Deck
Measuring the height of the deck is the next thing to do. You can secure the measuring tape at the floor of the deck or have a partner hold it for you. Be sure that the measuring tape is as perfectly vertical as can be to get the most accurate measurement. A level will be helpful.
Step 3 - Calculate the Stair Tread
The tread is the width of the step from back to front, the part you step on. The product of the riser height multiplied by two, plus the tread width, should be about 24 to 26 inches. For example, if your riser is seven inches tall, multiply that by two, giving you 14. The tread will have to be 10 to 12 inches because 10 to 12 inches added to 14 is between 24 and 26 inches.
Building the Steps
Step 1 - Pour the Foundation
You need to add a kicker plate when pouring the foundation. The kicker plate is simply a board that is secured to the stair foundations with concrete nails or bolts.
Step 2 - Make the First Stringer
The first stringer, which is a pattern cut board that is used to help form the size of the stairs, will be made from the calculations from Step 3 of the previous section. On the short arm of a framing square, make a mark that indicates the dimension of the height. The marked side of the framing board will be placed at the outside edge of the board. Holding the square securely in place, slide it up and down until the long arms width dimension is on the board’s edge. Now trace the outside edge of the framing square. It should look like a "V".
Step 3 - Continue Tracing Treads
Your board will then look like three "V"s together (VVV).
Step 4 - Fit the Bottom around Kicker Plate
You will fit the bottom of the stringer to the kicker plate by subtracting the thickness of the tread from the bottom of the stringer and then notching out a section, making it fit.
Step 5 - Cut along the Trace
Use a handsaw to cut the trace lines made prior.
Step 6 - Cut Second Stringer
You can use the first stringer and make an identical cut from it to make your second stringer. You will want to be sure to check the deck’s alignment before doing so. You may have to measure more accurately if the alignment isn’t right.
Step 7 - Attach Stringer to Plate
Attach the joists to the tops of the stringers with angle brackets or bolts. Lag screws or angle irons will connect the bottom of the stringers to the kicker plate.
Cut the treads and risers to the stairway width you want. Just be sure to leave a 3/4 of an inch overhang on both sides.
Now nail the risers in place. You can also screw them in place if you prefer. Add the treads. The back of the treads will be attached to the bottom edges of the risers.