# Every square, bundle and run. Counted.

> Enter the house and the roof pitch. StudSheet works out the roof area with the slope factor, the bundles, starter and ridge cap, underlayment, ice barrier, drip edge and vents, the siding squares and the gutter runs, with the math shown, then prices it for an estimate the client signs on their phone.

## The exterior Sheets

- **[Shingle roof](https://studsheet.com/sheets/roofing)**: gable, hip or shed roofs in architectural, 3-tab or designer shingles; squares with the pitch factor and waste, starter, hip and ridge cap, underlayment, ice barrier, drip edge, flashing, vents and nails, and the tear-off weight for the dumpster.
- **[Siding](https://studsheet.com/sheets/siding)**: vinyl, fiber-cement or engineered-wood lap siding by the square, with house wrap, starter, J-channel, corners and trim.
- **[Gutters and downspouts](https://studsheet.com/sheets/gutters)**: aluminum or vinyl sections or seamless aluminum, downspouts sized to the roof they drain, hangers, corners, end caps and outlets.

## From the roof Sheet: 40′ × 30′ house, 6/12 roof

40′ × 30′ house, 6/12 roof: 1503 sq ft of roof is 50 bundles of shingles (architectural, 10% waste), with the underlayment, ice barrier, drip edge and nails.

| Buy | Item | How StudSheet counts it |
|---|---|---|
| **50 bundles** | Architectural shingles (laminated) | 42′ × 32′ with the overhangs × 1.118 for the 6/12 slope = 1503 sq ft, + 10% waste (gable roof) = 16.53 squares × 3 bundles a square. Read the wrapper: some bundles cover a little less. |
| **2 bundles** | Starter strip shingles | 84 ft of eaves + 72 ft of rakes + 5% ÷ 105 ft a bundle. Starter on the rakes too keeps the edge shingles down in wind. |
| **2 bundles** | Hip and ridge cap shingles | 42 ft of ridge + 5% ÷ 30 ft a bundle (25–33 ft by brand). |
| **2 rolls** | Synthetic roof underlayment | 1503 sq ft ÷ 900 sq ft a roll after laps. |
| **1 box** | Plastic cap nails | About one per 2 sq ft of underlayment — follow the pattern printed on the roll. |

The Sheet has 11 lines like these, each with its math. Change a size and every line follows; on a job, each line takes your price. [The whole worked example](https://studsheet.com/sheets/roofing) · [Open the roof calculator](https://app.studsheet.com/p/roofing)

## Questions

### How many bundles of shingles are in a square?

A square is 100 sq ft of roof, and most shingles come 3 bundles to the square. Add waste for the cuts (about 10% on a simple gable roof, more on a hip roof), then the starter and the hip and ridge cap, which come in their own bundles. The [roofing Sheet](https://studsheet.com/sheets/roofing) shows each line.

### How does the pitch change the roof area?

Multiply the flat footprint by the slope factor, `sqrt(1 + (pitch / 12)²)`. A 4/12 pitch is ×1.054, 6/12 is ×1.118, 8/12 is ×1.202 and 12/12 is ×1.414. The roofing Sheet applies it for your pitch.