What is a 7/12 pitch in roofing?

A 7/12 pitch means that for every 12 horizontal inches, the roof rises 7 inches. This slope is common for gable roofs and aids in water drainage.

A plumb cut is the angle cut on the end of a rafter that allows it to fit flush against the ridge board. It is essential for proper alignment and structural integrity.

Why is snow load not sized in this context?

Snow load considerations depend on local climate and building codes. It is important to consult local regulations to determine appropriate snow load requirements for your specific area.

How do I calculate the rise of a roof with a 7/12 pitch?

To calculate the rise, use the formula: Rise = (Span/2) * (Pitch/12). For a 20 ft span, the rise would be (20/2) * (7/12) = 7.5 ft.

7/12 gable rafter on a 20 ft span

Learn about gable roof construction, including the 7/12 pitch, plumb cuts, and the importance of snow load considerations. Get insights into multipliers and design factors.

Formula SSC-2026.1

7.00 / 12 · 30.26°

Pitch angle

30.26°

Multiplier 1.1577

Common rafter

12 ft 7 15/16 in

Tail 1 ft 1 7/8 in

Cuts

30.26° plumb

59.74° seat

Roof area

658 ft²

6.58 squares

Shingle bundles

3 bundles per square + 10% waste

Sheathing / felt

23 sheets

2 underlayment rolls

Delivery weight

2,654 lb

1,204 kg · 70 lb bundles, 46 lb sheets, 28 lb rolls

Gable truss triangleLive scaled blueprint

Rise and run are scaled from the span, overhang, and pitch. The small triangle is the pitch ratio.

Bill of materials and shopping list
Item	Net	Waste	Order	Unit price	Line total	Source Spec Material / Tool
Architectural shingle bundles	6.58 squares	10%	22 bundles	USD	$924.00	Source Spec Material / Tool
4x8 CDX sheathing	20.6 sheets	10%	23 sheets	USD	$644.00	Source Spec Material / Tool
Underlayment rolls	658 ft²	overlap allowance	2 rolls	USD	$110.00	Source Spec Material / Tool
Ridge cap bundles	26.0 ft ridge	—	2 bundles	25 ft per bundle	—	Source Spec Material / Tool

Source links open a product search on the Amazon storefront for the selected currency. SiteSpecCalc may earn a commission. The link does not change the quantities above.

Side-by-side pitch comparison
Pitch	Degrees	Multiplier	Rafter	Squares	Bundles	Sheets
7.0/12	30.26°	1.158	12 ft 7 15/16 in	6.58	22	23
9.0/12	36.87°	1.250	13 ft 8 1/16 in	7.11	24	25

Show the deterministic formula

Angle = arctan(rise ÷ 12). Multiplier = √(1 + (rise ÷ 12)²). Gable run = span ÷ 2 − ridge thickness ÷ 2. Rafter length = (run + horizontal overhang) × multiplier.

Plumb cut = pitch angle. Seat cut = 90° − pitch angle. Area uses both slopes on a gable and one slope on a shed, and it includes a rake overhang equal to the eave overhang.

Bundles = ceiling of squares × 3 × 1.10. Sheets = ceiling of area × 1.10 ÷ 32. Rolls use 360 ft² effective coverage. Delivery weight plans 70 lb per bundle, 46 lb per sheet, and 28 lb per roll, then the header converts that pound total at 1 lb = 0.45359237 kg.

Contractor sign-off

Project: 7/12 gable rafter on a 20 ft span

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This sheet is an estimate for ordering and layout discussion. It is not a sealed design. Confirm the quantities with a licensed local professional and the authority having jurisdiction before you buy or build.

Engineering notes

A gable roof with a 7/12 pitch indicates that for every 12 horizontal inches, the roof rises 7 inches. This slope is essential for effective water drainage and can influence the overall structural integrity of the roof.

The multiplier is a factor used to calculate the total rise of the roof based on the span and pitch. For a 20 ft span, the rise can be calculated using the multiplier associated with the pitch ratio. Additionally, plumb cuts are critical in framing, as they determine the angle at which rafters meet the ridge board, ensuring a snug fit and proper load distribution.

Code reference

Consult local building codes for specific requirements regarding roof design and snow load considerations.

Field questions

What is a 7/12 pitch in roofing?: A 7/12 pitch means that for every 12 horizontal inches, the roof rises 7 inches. This slope is common for gable roofs and aids in water drainage.
What is a plumb cut?: A plumb cut is the angle cut on the end of a rafter that allows it to fit flush against the ridge board. It is essential for proper alignment and structural integrity.
Why is snow load not sized in this context?: Snow load considerations depend on local climate and building codes. It is important to consult local regulations to determine appropriate snow load requirements for your specific area.
How do I calculate the rise of a roof with a 7/12 pitch?: To calculate the rise, use the formula: Rise = (Span/2) * (Pitch/12). For a 20 ft span, the rise would be (20/2) * (7/12) = 7.5 ft.