Price a roof replacement from the cost build-up, not an average: measure squares including waste for pitch and complexity, cost tear-off per layer, add underlayment, flashing, ridge, vents and disposal, apply crew hours at burdened labor cost, add permits, then mark up to cover overhead and target profit.
One square is 100 square feet. Apply a pitch multiplier to the footprint area, then add waste, typically 10% on simple gables and 15% or more on cut-up roofs with valleys, hips and dormers.
Every line here is a real cost that gets forgotten somewhere.
State a decking allowance and a per-sheet change order rate in the contract. Absorbing rotten decking is one of the most common ways a roofing job loses its margin.
Total cost multiplied by (1 + markup) gives the price. Remember a 50% markup is a 33% margin. Steep, complex or high-access roofs justify higher markup because risk and non-productive time both rise.
WinkScope drafts a roofing scope with squares, pitch factors, tear-off layers and ventilation, prices materials against live vendor pricing, applies your labor rates and shows live margin. Add a decking allowance and change orders bill automatically when the deck opens up.
Divide the total roof surface area by 100, after applying the pitch multiplier to the building footprint, then add a waste factor of 10% to 15% or more depending on complexity.
Yes. Tear-off cost varies with layer count and disposal fees, and separating it makes multi-layer surprises easier to bill as a documented change.