Properly learning how to build deck stairs will enable you to create a beautiful entrance to your deck that will last for years to come. Deck stairs are the ideal choice for creating an entrance and exit for your deck when it is elevated above ground. Decks are one of the most commonly used outdoor constructions for any home, and the stairs are one of the most important parts of the deck.

To build deck stairs, you will need:

• 2 two-by-twelve boards
• A tape measure
• A hand saw
• Wood nails
• Cement mix
• Paper
• A pencil
• A calculator
• A shovel
• A level
• Pea gravel
1. The first step in building stairs for your deck is to measure the height from the deck surface to the ground. Mark the spot directly below where you want the stairs to be placed. The height will determine how high your staircase will be. The number should be recorded in inches. Divide this number by 7.5 inches, which is the average rise height. Record this number as it is the amount of stair treads you will need. Always round up when you are figuring out the number of stair treads.
2. The next thing you will need to do is divide the height by the number of treads. An example of this would be 108 inches divided by fifteen treads equals 7.2 inches. After doing this calculation, we determine that the rise will be 7.2 inches per tread. The standard depth of each tread is usually ten inches, so we will need to take the fifteen treads and multiply them by ten inches, making 150 inches.
3. Measure the final number that you determined from the spot marked on the ground for the landing. In this case, we would measure 150 inches from the spot immediately below the deck that was marked in step one. This spot will be the ground area for the stair landing. Measure a spot six inches in front and behind this space, and mark the entire width of the stair case.
4. Use a shovel to dig an area about six inches deep at this area. The hole will be one foot by the width of the stairs and six inches deep. Fill this area with cement until it is one inch below the ground, then add a layer of pea gravel.
5. While the cement dries, continue constructing the staircase by preparing the two-by-twelve board. The two-by-twelve boards will be the sides, or stringers, for the stairs. In order to figure out the length for these boards you have to use the following formula: a² x b² = c². For "a," take the height of the deck, which is the first measurement you took, and "b" is the distance of the landing. The example above would read: 108² x 150² = c², or 11,664 x 22,500 = 34,164². You then want to find the square root of c², in this case 184.825 inches. This number is the length of the two-by-twelve board. Cut the board to the specified length.
6. Begin by drawing a flat line for a return at the top end of the board, where the stringer will connect to the deck. Start at the top corner of the two-by-twelve board and begin marking the portions to be cut away with a framing square. Place the square to the rise calculated for your stairs, and the other to the width of your treads. Continue to trace along the inside edges of the square, making sure to line up each square with the line previously drawn. Draw another flat line on the bottom of the board, where the stringer will be placed on the ground. Cut out each outlined area.
7. Install the stringers by nailing them to the deck. It is important that these are level with each other, and spaced one inch in on both sides to allow a lip. Once the stringers are installed, begin to install the treads from the bottom of the stairs to the top, leaving a one inch lip on each side. Each tread should be nailed with two nails into each stringer.