Roofing, Siding & Exterior Building Products worked example

Warranty Reserve at 2.88% projected claim incidence: a worked example in roofing, siding & exterior building products

This scenario runs the warranty reserve calculation on the strong side: 2.88% projected claim incidence, with every other input held at its documented default. A product manager uses it to size the dollar reserve booked against long-term finish or weather warranties on a roofing or siding shipment.

The inputs for this scenario

  • Squares shipped under warranty: 1,200 squares (unchanged)
  • Expected claim cost per square: 45 $/square (unchanged)
  • Projected claim incidence: 2.88 % (raised for this scenario; the documented default is 2.5)
  • Admin & inspection overhead: 150 $ (unchanged)

Working through the calculation

  • Applying the documented formula (Total warranty reserve = squares shipped x claim cost per square x claim incidence + admin overhead) to the inputs above produces each figure below.
  • At this operating point the engine returns 1,705 $ for total warranty reserve cost, the number this scenario is built around.
  • At this operating point the engine returns 1.42 $ / piece for warranty reserve cost per unit.
  • At this operating point the engine returns 1,555 $ for variable warranty reserve cost.
  • At this operating point the engine returns 150 $ for fixed warranty reserve adder.

How this compares with the baseline

  • Against the tool's baseline example, where projected claim incidence sits at 2.5% and the headline result is 1,500 $, this scenario comes in 13.68% above the baseline at 1,705 $.
  • Use it when booking a warranty accrual for a shipment, pricing warranty into a product line, or stress-testing reserves against a rising claim trend. Treat this as a target state: the delta against the baseline quantifies what the improvement is worth before you commit to chasing it.

Results at a glance

  • Total warranty reserve cost: 1,705 $ (headline result)
  • Warranty reserve cost per unit: 1.42 $ / piece
  • Variable warranty reserve cost: 1,555 $
  • Fixed warranty reserve adder: 150 $

Run it with your numbers

  • Every input above is editable in the live Warranty Reserve calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.