Onregelmatig Schilddak Calculator voor Ongelijke Dakhellingen

How to use it: enter both pitches and one horizontal run on roof A. The calculator finds the roof B run that reaches the same height at a square (90-degree) eave corner.

Geometry. The roof planes are z = slope A × x and z = slope B × y. Their intersection fixes the hip plan line. True length combines both plan runs and the rise. Each backing bevel is the roof slope seen in a vertical section perpendicular to that hip line.

The result above uses these exact values. This snapshot is included when the page is printed so the output can be checked against the original measurements.

Roof A pitch rise

6

Roof A pitch run

12

Roof B pitch rise

9

Roof B pitch run

12

Roof A reference run

3600 mm

Jack spacing along eaves

600 mm

Primary result: True hip length: 4686.1 mm.

• Measure from the datum or reference edge described by this tool, and do not mix inside, outside and centerline dimensions.
• Keep inputs in the displayed units and preserve more precision than the final cutting or purchasing tolerance requires.
• When the result is close to a limit, verify it with a test piece, field measurement, manufacturer drawing or qualified project professional.

This assumes straight eaves meeting at 90 degrees and pitches rising from the same eave elevation. Values are theoretical face-line geometry with no ridge thickness, overhang, birdsmouth, timber-width, housing, or connection deductions. Backing bevels are referenced from level across the member. Verify conventions and a test cut locally. This is not structural sizing or code approval.