Saturday, February 6, 2010

Gonna fly now..

Floor to floor height: 10'-3 1/4"
Divide by 7: 17.6014
Round off to get the number of treads: 17
You have one less riser then treads: 16
Divide 10'-31/4" by 17: 7 1/4"
7 1/4" is the height of each riser, for a total of 17 from the first floor to the second.

Multiply 7 1/4" x 2: 14 1/2".
Subtract this from 25: 10 1/2"
10 1/2" is the size of each tread, front to back.

Multiply number of treads, 16, times 10 1/2": 168"
168" is the length of the stairs --the run-- from the beginning of the first step to the end of the last.

The above is the basic calculations for figuring out the rise and run of the stairs for our house. Its simple until you account for the thickness of the finish floor and the difference in thickness between tread thickness and floor material. Its all simple and everything when its done, but I spent a bunch of time rechecking my calculations from the day before and eventually confirmed that it was all correct.

That allowed me to start on actually building the first run of stairs up to the landing. This is fun stuff too, involving a carpenters square, and two brass nuts that attach to the square at the markings for the rise and the run. The steps are laid out rise then run, rise then run all the way to the top step.

Accuracy is the name of the game here. Theory and execution should be a close to the same as possible.

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