BUDGET & SCOPE
What goes into a tile roof estimate?
Square footage is only the starting point. Compare the same work, identify allowances, and separate a planning calculation from a contractor’s site-specific quote.
What is a roofing square?
One roofing square means 100 square feet of roof surface. A 3,000-square-foot roof is 30 squares. Interior living area is not roof area: overhangs, garages, roof slope, and the layout can change the amount of surface being covered. Use a roof measurement supplied by a professional when you have one.
How the planning estimator works
The estimator includes the main house and any optional detached buildings separately. It divides total interior square footage by one, two, or three stories for each building, assumes equal floor sizes, adds a 20% roof-size allowance, and applies a blended $14 installation planning rate per estimated roof square foot. It shows a central planning amount and a range 10% below and above it. These assumptions are not measurements. Garages, roof pitch, unequal floors, and actual project requirements can put a quote outside that range. It is not a bid or insurance valuation.
Why a small repair is different
Replacing a handful of tiles cannot reliably be priced by multiplying the entire roof area by a new-roof rate. A repair can include mobilization, access, locating compatible tiles, opening the affected area, underlayment work, and labor. Ask for a site-specific repair quote. The calculator on this website estimates replacement planning costs, not individual tile repairs.
Ask what is included
Use a checklist for removal, disposal, tile, underlayment, flashing, attachment, permit fees, inspections, and cleanup. Ask whether the contractor expects decking repairs or structural work and how those would be priced. Do not add a removal allowance twice if it is already included in a quoted rate.
Compare cost with scope and risk
A lower total may reflect fewer included tasks, a different product, or an unresolved allowance. Ask each bidder the same questions. Keep insurance payment discussions separate from the price of the actual roofing work, and do not treat a planning range as a coverage promise.
Further reading
This Old House: published tile installation cost ranges ↗
General homeowner education. Site-specific work must follow applicable requirements and the selected product’s installation instructions.