What a roof replacement costs, and what changes the number
Roofing is priced by the square, a hundred square feet of roof surface, but the number of squares is the part that varies least between quotes.
What raises the price beyond size
Pitch. A roof steep enough that a crew cannot walk it needs staging and takes longer. Complexity: every valley, dormer, hip and skylight is cutting, flashing and labor that a simple gable does not have. Layers, because removing two is roughly twice the tear-off and twice the disposal. Access, because a house where the dumpster cannot get near the work adds hours of carrying. And height, since a third story changes the equipment.
The line item nobody can quote accurately
Decking replacement. Nobody knows how much of the plywood or plank sheathing underneath is soft until the old roof is off. Reputable quotes handle this by stating a price per sheet and an assumed number; quotes that ignore it entirely are not cheaper, they are just less complete.
Ask what the per-sheet price is and how many sheets are assumed. It is the single most useful question you can ask about a roofing quote.
Where quotes genuinely differ
Underlayment: synthetic or felt, and whether ice-and-water shield goes at the eaves and in the valleys or only where code demands. Flashing, replaced or re-used. Ventilation, whether the existing arrangement is being corrected or simply reinstalled. Warranty: the manufacturer covers the material, the contractor covers the labor, and the second is worth more than the first.
Where the house sits moves the number before anything on the roof does. A tear-off inside the Montgomery County line (Rockville, Silver Spring) carries labor rates, permit timelines and disposal arrangements that the same crew does not face on a comparable house in Bowie. None of that appears as a line item, and all of it is in the total.
Before you sign, make every bidder answer
- How many layers come off, and is disposal included?
- This one answer separates two projects that look identical on the driveway. Get the count, and get the dumpster stated inside the number rather than beside it.
- What is the per-sheet price for decking replacement?
- It is the honest way to price what nobody can see yet. Bids without it are not cheaper; they are simply less finished, and the difference surfaces mid-job.
- What waste factor is assumed, in writing?
- Cut-up rooflines waste real material at every hip, valley and starter run. A written percentage lets you compare two bids that otherwise look the same on square footage.
- New flashing, or reused and sealed?
- New metal at every junction costs more on paper and less across the life of the roof. Sealing over old flashing is where an inexpensive quote gets inexpensive.
- What exactly does the ventilation scope include?
- Intake and exhaust by name, balanced to each other. In a humid summer climate it is the single correction that changes how long the new covering lasts, and it is nearly free while the roof is already open.
Next step: Roof replacement
Prices vary by property, by material and by provider. This page describes what goes into a quote; it is not a price list and nothing here is a quote.