Quick Answer: How to Calculate Raked Wall Studs
For a raked (sloping) wall, calculate stud lengths by adding the slope rise per stud spacing to the shortest stud height. Stud spacing is typically 450mm or 600mm centres in Australian framing per AS 1684. The slope rise per stud equals: stud spacing × tan(pitch angle).
For two-height walls, enter your tallest and shortest wall heights plus stud spacing in the calculator above.
Raked Wall Calculator — Calculate Raking Wall Stud Lengths
Calculate stud lengths for raked (angled) walls including cathedral ceilings, skillion roofs, and gable ends. Enter your wall dimensions and roof pitch to get individual stud lengths instantly with our free raked wall calculator.
What is a Raked Wall?
A raked wall follows the slope of a roof rather than being flat across the top. Common in cathedral ceiling designs, skillion roof buildings, and gable end walls. Each stud is a different length, making accurate calculation essential. Raked walls are one of the most common framing scenarios in Australian residential construction, particularly in modern home designs that favour open-plan living with vaulted ceilings.
How to Calculate Raked Wall Stud Lengths
The fundamental formula for raked wall stud calculation is:
Stud Length = Shortest Wall Height + (Stud Position × tan(Roof Pitch Angle))
For example, with a 2,400mm low wall, 600mm stud spacing, and a 22.5° pitch:
- Stud 1 (at 0mm): 2,400mm
- Stud 2 (at 600mm): 2,400 + (600 × tan 22.5°) = 2,400 + 249 = 2,649mm
- Stud 3 (at 1,200mm): 2,400 + (1,200 × tan 22.5°) = 2,400 + 497 = 2,897mm
- Stud 4 (at 1,800mm): 2,400 + (1,800 × tan 22.5°) = 2,400 + 746 = 3,146mm
Each stud increases by the same increment: spacing × tan(pitch). The calculator above handles this automatically for any number of studs.
Common Raked Wall Angles in Australian Homes
| Pitch | Degrees | Rise per 600mm | Common Use |
|---|---|---|---|
| 5 deg | 5° | 52mm | Skillion roof, Colorbond |
| 10 deg | 10° | 106mm | Low-pitch metal roofing |
| 15 deg | 15° | 161mm | Standard skillion, minimum for tiles |
| 22.5 deg | 22.5° | 249mm | Cathedral ceilings, popular residential |
| 25 deg | 25° | 280mm | Standard tile roof pitch |
| 30 deg | 30° | 346mm | Steep gable ends |
| 35 deg | 35° | 420mm | Traditional pitched roof |
Common Raked Wall Applications
- Cathedral ceilings — living areas with exposed roof slope, popular in modern Australian homes
- Skillion roofs — single-slope roofs on modern homes and extensions
- Gable ends — triangular wall sections at roof peaks
- Clerestory windows — raised wall sections for natural light
- Mezzanine walls — partial-height walls following roof slope in loft conversions
NCC and AS 1684 Framing Requirements for Raked Walls
Under AS 1684 (Residential timber-framed construction), raked walls must meet specific framing requirements:
- Stud spacing: Maximum 600mm centres for load-bearing walls, 450mm in high-wind areas (N3+)
- Top plate: Raked walls require a continuous top plate fixed to each stud with the correct nail pattern
- Bracing: Raked walls typically require additional bracing because the angled top plate creates different load paths. A minimum of one bracing panel per 9 metres of raked wall is typical
- Noggins: Horizontal nogging at mid-height for walls exceeding 2,700mm. For raked walls where some studs exceed this height, nogging is required in those bays
- Connection: Top plate to rafter or truss connection must use framing anchors or skew nailing per AS 1684 Table 9.6
Raked Wall Framing Tips from Experienced Builders
“Always mark and cut your raked wall studs on the ground before standing the frame. Set up a cutting station with your shortest stud as a template, then add the increment for each subsequent stud. It is faster and more accurate than measuring each one individually.”
— Experienced Australian carpenter, 20+ years residential framing
- Cut all studs before assembly: Calculate all lengths first, label each stud with its position number
- Account for plate thickness: Subtract the top and bottom plate thickness (usually 35mm each for 90×35 framing) from your floor-to-roof measurement
- Bevel the top cut: The top of each stud needs a bevel cut matching the roof pitch angle so the top plate sits flat
- Add 10mm tolerance: Cut studs 5-10mm long and plane to fit — easier than packing short studs
- Use a storey pole: For long raked walls, set up a storey pole at each end to ensure the rake line is straight
Stud Timber Sizes for Raked Walls
| Stud Size | Max Height (N1/N2) | Max Height (N3+) | Common Use |
|---|---|---|---|
| 70x35mm | 2,700mm | 2,400mm | Internal non-load-bearing |
| 90x35mm | 3,000mm | 2,700mm | Standard external walls |
| 90x45mm | 3,600mm | 3,000mm | Tall raked walls |
| 140x35mm | 4,200mm | 3,600mm | Cathedral ceilings, high walls |
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