A roof measurement report packs every number you need to estimate, order material, and price labor. But the first time you open one, the legend looks like a math test. This guide walks through every line item — squares, pitch, ridge, hip, valley, eave, rake, drip edge, and waste factor — so you can quote with confidence and stop overordering.
- →1 square = 100 sq ft of roof area (not floor area).
- →Pitch is rise over run, written X/12. Steeper = more material + more labor.
- →Ridges, hips, valleys, eaves, and rakes each carry their own line items.
- →Waste factor is added after the geometry — typical 10–15%, up to 22% on cut-up roofs.
- →Always cross-check total area to predominant pitch ratio (sanity test).
The cover page — at a glance
Every report opens with a top sheet showing total roof area, predominant pitch, ridge & hip linear feet, valley LF, eave LF, rake LF, and the suggested waste factor. This is the bid-ready summary — most experienced estimators quote off the cover page and only dig into the detail pages for verification or supplements.
Squares — the master number
1 square = 100 square feet of roof surface area (not floor area). A simple 30-square house has 3,000 SF of actual roof. The number is reported with pitch already factored in — a steep 12/12 roof on a 1,500 SF footprint can easily measure 25+ squares because the slope adds surface area.
Sanity-check the squares
Quick check: footprint × pitch multiplier should approximate total squares. A 6/12 roof multiplier is 1.118; a 12/12 is 1.414. If a 2,200 SF footprint at 6/12 reports as 35 squares, that's reasonable (24.5 base × 1.118 + cut-up). If it reports as 55, something's off — verify before bidding.
Pitch — the cost driver
Pitch is written as rise over run in inches per foot — a 6/12 pitch rises 6 inches for every 12 inches horizontal. The report shows predominant pitch (the most common slope) and a pitch breakdown if multiple slopes exist.
| Pitch | Multiplier (footprint → roof) | Labor impact |
|---|---|---|
| 3/12 | 1.031 | Standard |
| 6/12 | 1.118 | Standard |
| 8/12 | 1.202 | +10–15% labor |
| 10/12 | 1.302 | +25–35% labor (toe boards required) |
| 12/12 | 1.414 | +45–60% labor (roof jacks + safety) |
Ridges & hips
Ridge = horizontal line at the top of the roof where two slopes meet. Hip = sloped line where two roof planes meet at an outside corner. Both require ridge cap shingles and ridge vent (if vented). Reports give linear feet of each.
Estimating tip: 1 bundle of hip-and-ridge cap covers ~22 linear feet. A house with 60 LF of ridge + 40 LF of hip needs ≈ 5 bundles. Don't forget closure foam at hip-to-ridge intersections on vented systems.
Valleys
Valleys are the inside corners where two slopes meet — water concentrates here. Reports give valley linear feet so you can order ice & water shield (always required at valleys per IRC R905.1.2) and valley metal if specified.
Eaves & rakes
Eave = bottom horizontal edge of the roof (where the gutters hang). Rake = sloped edge along the gable end. Both get drip edge per IRC R905.2.8.5 — eave drip edge underneath the underlayment, rake drip edge over the underlayment. Reports give linear feet of each.
Drip edge calc
Drip edge comes in 10 ft sections. Total LF = eave LF + rake LF. Add 5–8% for cuts and waste. A house with 120 LF eave + 80 LF rake needs ≈ 22 sections.
Waste factor — the line item that kills budgets
Waste factor is the % added to base squares to account for cuts, starter strips, and cap material. The report suggests a number based on geometry — simple gable: 8–10%. Hip with valleys: 12–15%. Cut-up cottage with dormers: 18–22%.
Material order math
If the report shows 30 squares and 12% waste: order 30 × 1.12 = 33.6 squares. Round up to 34. At 3 bundles per square, that's 102 bundles. Always order full pallets when shipping cost favors it; the homeowner doesn't pay more if you have a half-bundle left.
Cross-checking before you bid
- Total area ÷ pitch multiplier ≈ footprint (Google satellite view should match)
- Ridge LF + hip LF + valley LF should look reasonable for the building shape
- Eave LF + rake LF should equal roughly the perimeter at gutter line
- Waste % should match the visual complexity (more dormers = higher waste)
What to do when the report looks wrong
Reports are generated from imagery; occasionally a tarp, snow patch, or tree obscures part of the roof. If the geometry doesn't match what you see on site, request a re-measure (RoofGenius offers free re-measures within 30 days; EagleView charges). Never bid off a report you don't trust.
Faster-than-the-cover-page quoting
RoofGenius pipes measurement reports directly into the Estimator — squares, pitch, ridge, valley, eave, rake, and waste auto-populate the pricing book. The estimate is built before you finish reading the cover page. See the integrated workflow.