ToolHuts

Praktische tools voor nauwkeurig werk

Veelhoekig Prieeldak & Sparren Calculator

Bereken standaardsparren en hoekkeper-hartlijnen, stijging, plattegrondhoeken en dakvlakoppervlak voor regelmatige daken met 3 tot 16 zijden.

Bereken de indeling, controleer het diagram en druk het resultaat af voor de werkplaats of bouwplaats.

mm

Measure one outside wall face of a regular polygon.

mm
Hip rafter centerline2878.5mm
Common rafter centerline2699.2mm
Roof rise1207.1mm
Building apothem2414.2mm
Plan half-angle22.50deg
Roof face area21.59

Centerline lengths run from the wall or fascia polygon to the central apex. Apply the ridge block, seat and tail details from the framing plan before cutting.

Werking

Enter the number of equal wall sides and the length of one side. The apothem is the horizontal common-rafter run; the center-to-corner radius is the hip plan run. Roof pitch converts those plan runs into true centerline lengths.

Worked example: an eight-sided gazebo with 2000 mm wall sides and a 6-in-12 pitch has a 2414.2 mm wall apothem and about 1207.1 mm of rise before the overhang is applied.

Voorbeeld met huidige invoer

Het resultaat hierboven gebruikt precies deze waarden. Deze momentopname wordt bij het afdrukken opgenomen om de uitvoer met de oorspronkelijke metingen te controleren.

Number of sides
8
Wall side length
2000 mm
Pitch rise
6
Pitch run
12
Horizontal overhang
300 mm

Hoofdresultaat: Hip rafter centerline: 2878.5 mm.

Vóór gebruik van het resultaat

  • 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.

Beperkingen

This assumes a regular polygon with a central apex and one common pitch. It does not size structural members or deduct ridge blocks, seats, tails, fascia, birdsmouths or member thickness. Check the actual wall polygon corner-to-corner before cutting rafters.

Veelgestelde vragen

Does side length include the overhang?

No. Enter the wall side length and the horizontal overhang separately. The tool projects the roof perimeter outward from the wall polygon.