Frequently asked questions

We use airborne LiDAR — laser scans flown over U.S. cities by the USGS 3D Elevation Program, NOAA and state agencies. Each scan records the exact 3D position of millions of points on rooftops. From the points that land on a building we compute the roof’s pitch and area.

The free result is a preliminary estimate: building outline times the measured slope, shown with a likely range. It is meant for a first estimate or a ballpark quote. The full report in the RoofTap app reconstructs every roof facet in 3D. Neither replaces an on-site inspection before you order materials.

Yes. The roof area, pitch and squares on this site are free, with no sign-up. The full 3D roof report, PDF export, client links and route planning are in the RoofTap iPhone app.

A roofing square is 100 square feet of roof surface. A 2,400 sq ft roof is 24 squares. Material is usually ordered by the square plus a waste allowance for cuts, hips and valleys — typically 10–15% on a simple roof.

We only measure where public LiDAR exists and has passed our quality checks. Coverage is wide in most U.S. metro areas, but some places have no scan, an old or sparse scan, or a scan we are still validating. Heavy tree cover or a house built after the scan can also prevent a measurement.

No. They are typical U.S. material-only prices per square, adjusted to your state’s price level (BEA Regional Price Parities). They exclude labor, tear-off, disposal, delivery and tax. Use your supplier’s prices for an actual bid.

Roofing contractors, estimators and sales reps who want a first roof estimate before driving to the job — and homeowners who want to understand their roof before getting bids.