107 — Roof Line

The roof line is what the top of the panel gets cut to. Six segments, each a straight run with a height at either end.

Two ways in:

  • Main Panel Details → tick Roof Line

  • ConstructiVision menu → Roof Line (c:cv-feat-roofline)

Note

This lesson also exists in the browser. Work it in ConstructiVision on the web — same steps, same values, so you can follow either and end up with the same panel.

The row

column

what it means

Enable

whether this segment exists

Meas From / Snap To

which end the distance is read from, and which edge

Distance

where the segment starts along the panel

Length

how far it runs

Elev Left, Elev Right

the height at each end

Everything about the slope is in that last pair. Equal, and the segment is flat — a parapet. Different, and it slopes between them.

The slope is 4:12

Not an example number. Every roof slope in this shop is 4:12 — four inches of rise for every twelve of run — and the lesson uses it so the arithmetic is the one you will actually do:

run 240"  ->  rise = 240 x 4/12 = 80"
Elev Left  240"   (20'-0")
Elev Right 320"   (26'-8")

If you are checking a panel and the two elevations do not differ by a third of the run, either it is not a 4:12 segment or one of the numbers is wrong.

Steps

  1. Open Main Panel Details and tick Roof Line.

  2. Enable segment one.

  3. Distance 0, Length 240.

  4. Elev Left 240, Elev Right 320.

  5. OK, then OK.

  6. Reopen from the menu and set Elev Right to 240. The slope goes flat — a parapet instead of a pitch — and it draws on OK.

Multiple segments

A panel under a ridge needs two segments: one rising to the peak, one falling away. That is what six rows are for. Each segment picks up where the last left off, so the elevations have to agree at the join or the roof line steps.

What to take away

Two elevations per segment, and a slope that is always 4:12. Those two facts place the cut line on nearly every panel you will draw.