What goes up and down but never moves?

STAIRS

Objectives Students will… Identify and define the pieces within a basic set of stairs Calculate the proper dimensions and layout for the rise and run of a standard stringer, given a total rise.

Total Rise – The total height from one finished floor to the other finished floor

Total Run – The total length of the stairs

Risers – The vertical member of the stairs

Treads – The step

Stringers – The structure of the stairs, usually 2 or 3 2x12’s

Nosing – The extra lip on the tread

Landing – The beginning or end of each stairs, sometimes in the middle of a flight of stairs

Balusters or Spindles – Vertical pieces under the handrail, to prevent falling off of stairs, no more than 4” apart

Handrail – To help in assisting someone up or down the stairs

Kicker – A 2x4 let into the bottom of the stringers to prevent the stairs from “kicking” out

Hanger – Usually ¾” plywood attached to the top section of the stringers to mount the stairs to the floor above

Skirt board – Decorative trim board that goes along either side, usually, of a closed stairway

Newel post – Supports the handrail, can be decorative, found at the base of the stairs

Steps To Figure Rise And # Of Stairs Calculating riser height video – 3 minutes For all stair layouts you must know: # of risers and height, # of treads and depth Knowing the rise and run are the most crucial item in determining risers and treads. NEVER go off of a set of blueprints when determining risers and treads

Steps To Figure Rise And # Of Stairs From your rise and run of your stairway opening, you will be able to determine 4 things: # of risers, riser height, # of treads, and tread width Divide total rise (in inches) by 7 ½” Round answer UP to nearest WHOLE NUMBER THIS IS THE # OF RISERS Divide total rise by # of risers THIS IS THE RISER HEIGHT # of risers MINUS ONE = (# of treads) Divide run by NUMBER OF TREADS *** IF YOUR RISER HEIGHT OR TREAD DEPTH DO NOT FALL INTO THE ACCEPTABLE RANGE YOU MUST INCREASE OR DECREASE THE NUMBER OF RISERS!**

Turn a Decimal into a Fraction Multiply the decimal amount only by 16 (to get sixteenths of an inch) The new whole number is the new numerator (top half of the fraction)

Stair Guidelines 2 Risers + 1Tread ~ 25 (1 riser + 1 tread ~ 17) Treads should be about 10” TO 12” wide Risers should be about 6 ½” TO 8” high Minimum headroom from stairs to any point above should be 6’-8” Nosing should not exceed 1 ½” Minimum stair width is 36” (stairwell opening to be 39”)

Stair Guidelines The preferred angle of a stairway should be between 30 and 35 degrees When laying out the first riser THICKNESS OF THE TREAD should be deducted from the bottom If plywood is used as the hanger how much should be taken off of the top of the stringer? NONE, YOU MAY HAVE TO ADD THE THICKNESS OF THE RISER While only two stringers are required, 3 stringers are considered best practice. Stringers are usually made from 2X12 ALTHOUGH ENGINEERED LUMBER IS MORE STABLE AND STRONGER

Stair Guidelines A FRAMING SQUARE is used to establish the height of the HANDRAIL Handrails should be CLOSED in accordance with building and fire codes. Handrails help people up and down the stairs Spindles help prevent FALL-THROUGH and must be no further than 4 inches apart. When attaching the treads and risers using CONSTRUCTION ADHESIVE and SCREWS is the best practice.

Stair Layout Stair Layout – 24 minutes Circular Saw Safety – 25 min Saw blades – 7:30 minutes