Hip Cap Quantity
Determining quantity of hip caps to be used with horizontally run metal roofing systems requires some effort.
The compound angle that is created by a roof hip (outside corner) means that the exposure achieved by individual hip caps will vary based upon roof pitch.
For products using lineal hip caps, the quantity determination is relatively simple. It is based strictly upon knowing the lineal footage of hip line. Keep in mind, though, that the lineal footage of hip rafter will not be the same as the lineal footage of the common rafter for the abutting roof planes. If the system being installed uses individual one-per-course hip caps designed to lock over the shingles on either side of the hip, then the hip cap quantity is determined by the number of shingle courses. To determine this, take the lineal footage of the common rafter and, based upon the exposure of the shingles being installed, determine the number of shingle courses that will be installed. The hip cap quantity for each hip is then one per course.
Some roofs are built with unequal roof pitches on either side of the hip. When this happens, special hip cap installation procedures must be taken with products that normally have individual one-per-course hip caps. Refer to Technical Bulletin #19 for further details on this.