Unit 10 - Stairway Construction

Stairway Construction For the installation of landscape decks, often times Landscape Contractors will have a difference in elevation between the deck surface and finished grade. This elevation is known as the “TOTAL RISE” of the deck. The total rise of the deck is an important measurement for staircase construction, because it will influence the amount of steps needed and the length of the staircase.

Stairway Construction For safety reasons, it is important to have steps of equal height and width. Steps of unequal heights and widths can throw off the “Stride” of the person climbing the stairs, and result in a fall, and possible injury.

Stairway Construction Nomenclature….. Total Rise - is the total height of elevation from finished grade, to the top of deck surface. Total Run – is the horizontal length of the staircase, and the amount it will protrude from the deck. Riser – is the actual height of the step. Average riser height is 7.5 inches, and they must be consistent from the top of the staircase to the bottom.

Stairway Construction Nomenclature….. Tread – is the width of the step, and also must be consistent throughout the staircase. Treads are typically 10” wide. Nosing – is the amount of overhang each tread has, typically 1-1 ½”. Stringers - are the side boards which hold the risers to the treads and the staircase to the deck. They are typically made of 2X10 or 2X12 boards, and are referred to as CLOSED or OPEN.

Stairway Construction The 4 rules of Stair construction….. #1 R+T = 17.5 +/- 1 Example: 7.5” rise 10” tread 7.5+10=17.5

Stairway Construction The 4 rules of Stair construction….. #2 R X T = 75 +/- 3 Example: 7.5” rise 10” tread 7.5 X10 = 75

Stairway Construction The 4 rules of Stair construction….. #3 2R + T = 25 +/- 1 Example: 7.5” rise 10” tread 15 X10 = 25

Stairway Construction The 4 rules of Stair construction….. #4 Slope should not exceed 35 degrees.

Stairway Construction Another helpful formula….. C = A + B 2 2 2