The Metal for a Hip Roof calculator computes the metal roof materials for a hip roof based on the dimensions.
INSTRUCTIONS: Choose units and enter the following:
- (S) Span of Roof
- (L) Length of Roof
- (P) Pitch (choose pitch from list)
- (oH) Overhang
- (PW) Panel Width (default 36"). This is the coverage width and not necessarily the measured width of the metal panels.
- (TO) Tolerance (default 3"). This is added to trim and panel lengths as a safety margin.
Metal for a Hip Roof (m): The calculator returns:
- (TA) Area: Total surface area of hip roof.
- (r) Ridge Cap: Length of the Ridge Cap (red)
- (j) Hip Ridge Length: Length of each individual hip ridge
- (tRC) Total Ridge Cap Trim: Covers the top ridge and hip ridges
- (sG) Snow Guard: Total length of snow guard to for under the ridge cap.
- Metal Panels: Number and max length of Metal Panels (36" wide coverage)
- (PL) Length of Panels
- (nP+) Number of Panels with no-reuse. This is conservatively high.
- (nP-) Number of Panels with reuse of cuts. This accounts for one panel used in multiple segments in the hips (see ECONOMY below)
- (α) Panel Angle: The angle of the hip cuts
- (mS) Metal Screws: number of screws needed to attach panels to roof.
- (aT) Angle Trim: Total length of Angle Trim (yellow)
However, these can be automatically converted to compatible units via the pull-down menu.
ECONOMY: This calculator provides two numbers of panels. The first (nP+) is a high number with no reduction in the number of panels based on reusing panel leftovers for additional sections (see graphic). When smaller sections are cut out of a panel of maximum length, it is possible in many cases to use the residual (leftover) for another section. This maximum number assumes that a full panel will be used for each section and therefore provides the maximum number of metal panels needed. The second (nP-) number of panels is lower, because it assumes that cuts making the hip ends will produce leftover pieces that can also be used (see diagram).
The Math / Science
A hip roof is basically a rectangular trapezoid volume has regular trapezoids in the front and back and triangles on the sides. The bottom and top rectangles are centered, form parallel planes and separated by the height.
Safety Tolerances
An addition of the TO parameter (default of 3") s added to the following dimensions.
- (r) Ridge Cap
- (sG) Snow Guard
- (j) Hip Covers
- (PL) Panel Length
- (aT) Angle Trim
It's better to have too much and have to cut it, than not enough.
Roof Types
