What’s math? It’s been too long since I actually had to do more than punch the numbers into the CM.
I’m trying to determine the least amount of carpet to order to fully carpet stairs. Winders at the top and bottom, straight run in between. The straight run is a no brainer (I got plenty of that) but the winder portions will be cut and laid one tread and riser at a time.
When the carpet flops over from the tread to the riser, the angle of the tread causes an offset in where the edge of the carpet falls and I need to calculate the additional width to cut to make up that difference without wasting expensive carpet.
The installer will hack off an oversized piece of carpet and then cut it down to fit. That’s unacceptable waste, especially since the stairs installation is an upcharge per tread and the per sq.ft. installation charge is based on the total amount ordered and not on the amount installed.
There was a thread a while back where the installer offered to dispose of the carpet offcut – for free. The poster objected to having to spend an additional $400 or so for waste. Can you blame him?
I can template this very easily but maybe there is a triangle formula that would give me my answer based on the knowns of run, rise, diagonals and the measured angles of the winders.
Replies
hypotenuse squared is = to sum of the squares of the other 2 sides in a right triangle
if not a right triangle, make smaller right triangles from it
basic trig
http://www.mathwizz.com/algebra/help/help22.htm
http://www.horacemann.pvt.k12.ny.us/academics/math/pcbch/trig/sohcahtoa.html
bobl Volo, non valeo
Baloney detecter WFR
There's no advantage to cutting wedges because of having to align the nap - it's "longest side (tread + riser + trim allowance)" x "width (width of delivered carpet that will produce the needed tread width + trim allowance) x "number of steps"".
If you really want to ignore the nap direction, then you have multiply the "number of steps" x "longest side (tread + riser + trim allowance)", and then "number of steps" x "shortest side (tread + riser + trim allowance)" and select which-ever sum is larger, then do your number of step multiplication. You can play with cutting the treads out of full widths (or a multiple, like ½) or cutting from cross-strips; but, any cookie-cutter methods beyond that will be a disaster (like, you can't cut some north-south and some east-west - they WILL look different).
I wrote a program (unfortunately, for OS/2 in PL/I and requiring PM/2) for a friend in the carpet business to optimize carpet cutting and nap-matching, it was an interesting exercise.
Phill Giles
The Unionville Woodwright
<nap-matching, it was an interesting exercise.>
As someone with young kids, I can agree with that!
Forrest - always glad to help