# How To Build Stairs - Part 1a

### Letters in Orange signify that the formula is on the free automatic staircase calculator.

The simplest set of stairs to make is a straight staircase as shown in Figure 1.

##### Figure 1 - Straight Stairs

The biggest obstacle to building a straight run set of stairs is space.

Besides requiring the "Total Run" of the stairs you need additional space at the bottom of the stairs in order to create a landing, which, at a minimum is the width of the stairs.

Stairs have some dimensional flexibility. However, there are guidelines and building codes which have set some minimum and maximum staircase design rules and numbers.

The one dimension that has no flexibility is the "Total Rise" as shown in Figure 2. This is the height of the staircase from the top of the finished basement floor to the top of the finished floor at the top of the stairs.

#### Table 1 - Fraction To Decimal Conversions

Fraction Decimal Fraction Decimal Fraction Decimal Fraction Decimal

1/32

0.0313

9/32

0.2813

17/32

0.5313

25/32

0.7813

1/16

0.0625

5/16

0.3125

9/16

0.5625

13/16

0.8125

3/32

0.0938

11/32

0.3438

19/32

0.5938

27/32

0.8438

1/8

0.125

3/8

0.375

5/8

0.625

7/8

0.875

5/32

0.1563

13/32

0.4063

21/32

0.6563

29/32

0.9063

3/16

0.1875

7/16

0.4375

11/16

0.6875

15/16

0.9375

7/32

0.2188

15/32

0.4688

23/32

0.7188

31/32

0.9688

1/4

0.25

1/2

0.5

3/4

0.75

1

1

Note: You will have to round decimal places to the closest 1/32 of an inch on conversion from decimal to fraction, see Table 3.

To determine the width of each step and the height of each riser you start with the "Total Rise" measurement. From this dimension you can determine how many risers and the height of each riser or stair. Most building codes have set a maximum stair rise of 7 3/4". For the purpose of this example we will use a "Total Rise" of 106 3/4".

The calculation to determine how many risers you require is:

#### 106 3/4 ÷ 7 3/4 = 13.77

As it is impossible to have a fraction of a number of risers, the number obtained is rounded off to the next highest whole number, in this case 14.

Continued.......

Part 1a

Part 1b

Part 2

Part 2b

Part 3

Part 4

Part 5

Part 6

Part 6b