Construction how-to guides
Step-by-step guides for the jobsite tasks behind the calculators: measuring a roof pitch, laying out a stair stringer with a framing square, cutting crown flat, and more. Every worked example is computed by the same tested code the CutOnce app runs.
Updated
- Roof framing
How to measure roof pitch
Four ways to read a roof's pitch, an attic level, a speed square, from the ground, or on the roof, then convert it to degrees and percent.
Read the guide → - Roof framing
How to cut rafters
Run, rise, line length, the ridge deduction, the tail, and the birdsmouth for a common rafter, plus how to read a framing-square rafter table.
Read the guide → - Stairs
How to calculate stair stringers
Riser count, riser height, tread depth, and total run worked step by step and held to IRC R311.7.
Read the guide → - Stairs
How to lay out stairs with a framing square
Set the stair gauges, step off each tread, cut the plumb and level lines, and drop the stringer so every riser finishes equal.
Read the guide → - Trim
How to cut crown molding flat
Find the spring angle and set the miter and bevel to cut crown flat on the saw table, worked at a square corner.
Read the guide →
Worked from the app's real math
The numbers in every guide are computed by the shared code the CutOnce app runs and checked against the app's own test suite on each build rather than entered by hand. Each guide pairs with the calculator that runs the same math, so you can read the method here and run your own numbers there.
The whole toolbox, offline
The app carries the full toolbox the guides describe: stairs, rafters, and roof framing plus materials, concrete, drywall, decks, and unit conversions, all working with no signal and exporting printable PDF plans.
