Lots of small details can impact the amount of insulation that you need for a 10×12 shed. People’s needs will differ based on roof styles, stud dimensions, and stud spacing.
The tables below reflect detailed calculations that tell you how much insulation your shed will need. We account for three different roof designs, five different stud spacings between 16-24 inches, and three different stud sizes.
A 10×12 shed will require approximately 386 ft² to 435 ft² of insulation, depending on the stud size, stud spacing, and whether the roof is flat, gabled, or skillion.
Assumptions the Calculations Are Based on
- We are assuming that the wall height is 8 ft. This is because 8 ft is a standard length for timber, boards, and other wall materials. It’s also the standard height of ceilings in construction.
- The calculations are based on the 10×12 measurements being taken on the exterior sides of the shed.
- A shed typically has no ceiling, so insulation will sit between the rafters as opposed to between the joists of a ceiling.
- The stud work for the 12-ft walls extends to the back edge of the stud work for the 10-ft walls. For example, if you’re using 2×4 studs, the first stud on the 10-ft wall will start 4 in. in.
- Our calculations do not include doors or windows. When tailoring the calculations to your own shed, determine the area of your doors and windows, add them up, and subtract this from the total area.
- The spaces created by the sides of the gable and skillion roofs will have the same angles on the external and internal points of the triangles created by the rafters.
For more detail on the calculations used below, refer to our explanation of how to calculate how much insulation you need for a 10×16 shed.
Dimensions of the Framework
There are three sizes of studs that are commonly used in sheds: 2×4, 2×6, and 2×8. If you use larger studs, you’ll be sacrificing interior space. Plus, it’s okay for the wall cavities to be narrow because there is no minimum R-value (insulation thickness) required for a shed.
We look at different choices for stud spacing: 16 in., 18 in., 20 in., 22 in., and 24 in. These are the most common spacings found in sheds.
Shed rafters will be similar to wall studs, either 2×4 or 2×6.
Rafters should be spaced 16 in. apart.
When calculating the insulation needed for the roof, we need to consider that a pitched roof has more area than a flat roof. A standard gable roof pitch is 4/12, meaning a rise of 4 in for every 12 in of run. A skillion roof is commonly pitched 10°.
Wall Insulation
12-Foot Walls
| Stud spacing | Real-life number of studs (including end studs) | Wall width excluding total stud width | Area requiring insulation (per wall) | Area requiring insulation (both walls) |
| 16 in. | 10 | 124 in. = 10.33 ft | 82.66 ft² | 165.32 ft² |
| 18 in. | 9 | 126 in. = 10.5 ft | 84 ft² | 168 ft² |
| 20 in. | 8 | 128 in. = 10.67 ft | 85.33 ft² | 170.66 ft² |
| 22 in. | 8 | 128 in. = 10.67 ft | 85.33 ft² | 170.66 ft² |
| 24 in. | 7 | 130 in. = 10.83 ft. | 86.67 ft² | 173.33 ft² |
10-Foot Walls
| Stud spacing | Real-life number of studs (incl. end studs) | Wall width excluding total stud width | Area requiring insulation (per wall) | Area requiring insulation (both walls) |
| 16 in. | 2×4: 6 2×6: 6 2×8: 6 | 2×4: 96 in. = 8 ft 2×6: 92 in. = 7.67 ft 2×8: 88 in. = 7.33 ft² | 2×4: 64 ft² 2×6: 61.33 ft² 2×8: 58.67 ft² | 2×4: 128 ft² 2×6: 122.66 ft² 2×8: 117.34 ft² |
| 18 in. | 2×4: 6 2×6: 6 2×8: 5 | 2×4: 96 in. = 8 ft 2×6: 92 in. = 7.67 ft 2×8: 90 in. = 7.5 ft | 2×4: 64 ft² 2×6: 61.33 ft² 2×8: 60 ft² | 2×4: 128 ft² 2×6: 122.66 ft² 2×8: 120 ft² |
| 20 in. | 2×4: 5 2×6: 5 2×8: 5 | 2×4: 98 in. = 8.17 ft 2×6: 94 in.= 7.83 ft 2×8: 90 in. = 7.5 ft | 2×4: 65.33 ft² 2×6: 62.67 ft² 2×8: 60 ft² | 2×4: 130.66 ft² 2×6: 125.34 ft² 2×8: 120 ft² |
| 22 in. | 2×4: 5 2×6: 5 2×8: 5 | 2×4: 98 in. = 8.17 ft 2×6: 94 in.= 7.83 ft 2×8: 90 in. = 7.5 ft | 2×4: 65.33 ft² 2×6: 62.67 ft² 2×8: 60 ft² | 2×4: 130.66 ft² 2×6: 125.34 ft² 2×8: 120 ft² |
| 24 in. | 2×4: 5 2×6: 5 2×8: 5 | 2×4: 98 in. = 8.17 ft 2×6: 94 in.= 7.83 ft 2×8: 90 in. = 7.5 ft | 2×4: 65.33 ft² 2×6: 62.67 ft² 2×8: 60 ft² | 2×4: 130.66 ft² 2×6: 125.34 ft² 2×8: 120 ft² |
For the Walls in Total
| Stud Spacing | 2×4 studs | 2×6 studs | 2×8 studs |
| 16 in. | 293.32 ft2 | 287.98 ft2 | 282.66 ft2 |
| 18 in. | 296 ft2 | 290.66 ft2 | 288 ft2 |
| 20 in. | 301.32 ft2 | 296 ft2 | 290.66 ft2 |
| 22 in. | 301.32 ft2 | 296 ft2 | 290.66 ft2 |
| 24 in. | 303.99 ft2 | 298.67 ft2 | 293.33 ft2 |
Roof Insulation
Flat Roof
Based on 16 in. rafter spacing.
| Number of rafters (including end rafters) | Width lost to rafters | Roof width (excl. width of rafters) | Area requiring insulation |
| 10 | 20 in. | 124 in. = 10.33 ft. | 103.33 ft² |
Gable Roof
Roof Panels
Based on a 4/12 pitch and 16 in. rafter spacing, we have the following information.
| Rise | 20 in. = 1.67 ft |
| Run | 5 ft |
| Pitch angle | 18.4 degrees |
| Length of roof panel (hypotenuse) | 5.27 ft = 63.25 in. |
| Number of rafters | 10 per panel/side |
Using this information, we can calculate how much area requires insulation on the roof panels.
| Roof panel width (excl. total rafter width) | Area requiring insulation (per panel) | Area requiring insulation (both panels) |
| 144 in. – 20 in. = 124 in. = 10.33 ft. | 54.46 ft² | 108.91 ft² |
Gable Spaces
The gable spaces (the triangles between the 10-ft walls and the roof panels) also need to be insulated.
The broad sides of the rafters of the roof panels as well as the rafter beam installed on top of the 10-ft wall stud work extend into this space, so the rafter size makes a difference.
We will be looking at 2×4 and 2×6 rafters.
Our article on 10×16 sheds explains in detail how to calculate gable space area.
| 2×4 rafters | 2×6 rafters | |
| Area of half the gable space | 204.06 in² | 84.04 in² |
| Area of one gable space | 408.12 in² = 2.83 ft² | 168.08 in² = 1.17 ft² |
| Total gable space area | 816.24 in² = 5.66 ft² | 336.16 in² = 2.34 ft² |
Total Gable Roof Area Requiring Insulation
| 2×4 rafters | 2×6 rafters | |
| Roof panels | 108.91 ft² | 108.91 ft² |
| Gable spaces | 5.66 ft² | 2.34 ft² |
| Total gable roof area | 114.57 ft² | 111.25 ft² |
Skillion Roofs
Roof Panel
10° is a common pitch for skillion roofs on sheds. Using this and 16 in. rafter spacings, we have the following dimensions:
| Rise | 1.76 ft. = 21.12 in. |
| Run | 10 ft |
| Pitch angle | 10° |
| Length of roof panel (hypotenuse) | 10.15 ft |
| Number of rafters | 10 |
Using this information, we can calculate how much area requires insulation on the roof panel.
| Roof panel width (excl. total rafter width) | Area requiring insulation |
| 144 in. – 20 in. = 124 in. = 10.33 ft | 104.85 ft² |
Gable Spaces
There are also triangular spaces on the sides of skillion shed roof designs, which have to be insulated, too. We will be looking at 2×4 and 2×6 rafters here as well.
| 2×4 rafters | 2×6 rafters | |
| Area of one gable space | 3.37 ft² | 1.64 ft² |
| Total gable space area | 6.74 ft² | 3.28 ft² |
Wall Extension Area
The skillion roof creates an extension of one of the 12-ft walls, from the top of the actual wall to the apex of the roof, which requires insulation.
The extension has studs, not rafters, and these will match the studs of the wall beneath it. So, 16 in., 18 in., 20 in., 22 in., and 24 in. rafter spacings and 2×4, 2×6, or 2×8 stud sizes.
| Stud spacing | Number of studs | Wall extension area requiring insulation coverage |
| 16 in. | 10 | 18.18 ft² |
| 18 in. | 9 | 18.48 ft² |
| 20 in. | 8 | 18.78 ft² |
| 22 in. | 8 | 18.78 ft² |
| 24 in. | 7 | 19.06 ft² |
It’s easier to incorporate the extension area into the total wall area. Here is the total wall area (10-ft walls + 12-ft walls + wall extension) that requires insulating for a skillion-roofed shed:
| Stud spacing | 2×4 | 2×6 | 2×8 |
| 16 in. | 128 ft² + 165.32 ft² + 18.18 ft² = 311.5 ft² | 122.66 ft² + 165.32 ft² + 18.18 ft² = 306.16 ft² | 117.34 ft² + 165.32 ft² + 18.18 ft² = 300.84 ft² |
| 18 in. | 128 ft² + 168 ft² + 18.48 ft² = 314.48 ft² | 122.66 ft² + 168 ft² + 18.48 ft² = 309.14 ft² | 120 ft² + 168 ft² + 18.48 ft² = 306.48 ft² |
| 20 in. | 130.66 ft² + 170.66 ft² + 18.78 ft² = 320.1 ft² | 125.34 ft² + 170.66 ft² + 18.78 ft² = 314.78 ft² | 120 ft² + 170.66 ft² + 18.78 ft² = 309.44 ft² |
| 22 in. | 130.66 ft² + 170.66 ft² + 18.78 ft² = 320.1 ft² | 125.34 ft² + 170.66 ft² + 18.78 ft² = 314.78 ft² | 120 ft² + 170.66 ft² + 18.78 ft² = 309.44 ft² |
| 24 in. | 130.66 ft² + 173.33 ft² + 19.06 ft² = 323.05 ft² | 125.34 ft² + 173.33 ft² + 19.06 ft² = 317.73 ft² | 120 ft² + 173.33 ft² + 19.06 ft² = 312.39 ft² |
The roof panel and gable spaces combined are the total roof area for a skillion roof.
| Roof panel area | Gable space area | Total roof area | |
| 2×4 | 104.85 ft² | 6.74 ft² | 111.59 ft² |
| 2×6 | 104.85 ft² | 3.28 ft² | 108.13 ft² |
Insulation Amount Required for 10×12 Shed
Flat Roof
2×4 Studs
| Stud spacing | Wall area | Roof area | Total area |
| 16 in. | 165.32 ft² + 128 ft² | 103.33 ft² | 396.65 ft² |
| 18 in. | 168 ft² + 128 ft² | 103.33 ft² | 399.33 ft² |
| 20 in. | 170.66 ft² + 130.66 ft² | 103.33 ft² | 404.65 ft² |
| 22 in. | 170.66 ft² + 130.66 ft² | 103.33 ft² | 404.65 ft² |
| 24 in. | 173.33 ft² + 130.66 ft² | 103.33 ft² | 407.32 ft² |
2×6 Studs
| Stud spacing | Wall area | Roof area | Total area |
| 16 in. | 165.32 ft² + 122.66 ft² | 103.33 ft² | 391.31 ft² |
| 18 in. | 168 ft² + 122.66 ft² | 103.33 ft² | 393.99 ft² |
| 20 in. | 170.66 ft² + 125.34 ft² | 103.33 ft² | 399.33 ft² |
| 22 in. | 170.66 ft² + 125.34 ft² | 103.33 ft² | 399.33 ft² |
| 24 in. | 173.33 ft² + 125.34 ft² | 103.33 ft² | 402 ft² |
2×8 Studs
| Stud spacing | Wall area | Roof area | Total area |
| 16 in. | 165.32 ft² + 117.34 ft² | 103.33 ft² | 385.99 ft² |
| 18 in. | 168 ft² + 120 ft² | 103.33 ft² | 391.33 ft² |
| 20 in. | 170.66 ft² + 120 ft² | 103.33 ft² | 393.99 ft² |
| 22 in. | 170.66 ft² + 120 ft² | 103.33 ft² | 393.99 ft² |
| 24 in. | 173.33 ft² + 120 ft² | 103.33 ft² | 396.66 ft² |
Gable Roof
2×4 Rafters and 2×4 Studs
| Stud spacing | Wall area | Roof area | Total area |
| 16 in. | 165.32 ft² + 128 ft² | 114.57 ft² | 407.89 ft² |
| 18 in. | 168 ft² + 128 ft² | 114.57 ft² | 410.57 ft² |
| 20 in. | 170.66 ft² + 130.66 ft² | 114.57 ft² | 415.89 ft² |
| 22 in. | 170.66 ft² + 130.66 ft² | 114.57 ft² | 415.89 ft² |
| 24 in. | 173.33 ft² + 130.66 ft² | 114.57 ft² | 418.49 ft² |
2×4 Rafters and 2×6 Studs
| Stud spacing | Wall area | Roof area | Total area |
| 16 in. | 165.32 ft² + 122.66 ft² | 114.57 ft² | 402.55 ft² |
| 18 in. | 168 ft² + 122.66 ft² | 114.57 ft² | 405.23 ft² |
| 20 in. | 170.66 ft² + 125.34 ft² | 114.57 ft² | 410.57 ft² |
| 22 in. | 170.66 ft² + 125.34 ft² | 114.57 ft² | 410.57 ft² |
| 24 in. | 173.33 ft² + 125.34 ft² | 114.57 ft² | 413.24 ft² |
2×4 Rafters and 2×8 Studs
| Stud spacing | Wall area | Roof area | Total area |
| 16 in. | 165.32 ft² + 117.34 ft² | 114.57 ft² | 397.23 ft² |
| 18 in. | 168 ft² + 120 ft² | 114.57 ft² | 402.57 ft² |
| 20 in. | 170.66 ft² + 120 ft² | 114.57 ft² | 405.23 ft² |
| 22 in. | 170.66 ft² + 120 ft² | 114.57 ft² | 405.23 ft² |
| 24 in. | 173.33 ft² + 120 ft² | 114.57 ft² | 407.9 ft² |
2×6 Rafters and 2×4 Studs
| Stud spacing | Wall area | Roof area | Total area |
| 16 in. | 165.32 ft² + 128 ft² | 111.25 ft² | 404.57 ft² |
| 18 in. | 168 ft² + 128 ft² | 111.25 ft² | 407.25 ft² |
| 20 in. | 170.66 ft² + 130.66 ft² | 111.25 ft² | 412.57 ft² |
| 22 in. | 170.66 ft² + 130.66 ft² | 111.25 ft² | 412.57 ft² |
| 24 in. | 173.33 ft² + 130.66 ft² | 111.25 ft² | 415.24 ft² |
2×6 Rafters and 2×6 Studs
| Stud spacing | Wall area | Roof area | Total area |
| 16 in. | 165.32 ft² + 122.66 ft² | 111.25 ft² | 399.23 ft² |
| 18 in. | 168 ft² + 122.66 ft² | 111.25 ft² | 401.91 ft² |
| 20 in. | 170.66 ft² + 125.34 ft² | 111.25 ft² | 407.25 ft² |
| 22 in. | 170.66 ft² + 125.34 ft² | 111.25 ft² | 407.25 ft² |
| 24 in. | 173.33 ft² + 125.34 ft² | 111.25 ft² | 409.92 ft² |
2×6 Rafters and 2×8 Studs
| Stud spacing | Wall area | Roof area | Total area |
| 16 in. | 165.32 ft² + 117.34 ft² | 111.25 ft² | 393.91 ft² |
| 18 in. | 168 ft² + 120 ft² | 111.25 ft² | 399.25 ft² |
| 20 in. | 170.66 ft² + 120 ft² | 111.25 ft² | 401.91 ft² |
| 22 in. | 170.66 ft² + 120 ft² | 111.25 ft² | 401.91 ft² |
| 24 in. | 173.33 ft² + 120 ft² | 111.25 ft² | 404.59 ft² |
Skillion Roof
2×4 Rafters and 2×4 Studs
| Stud spacing | Wall area | Roof area | Total area |
| 16 in. | 165.32 ft² + 128 ft² + 18.18 ft² | 111.59 ft² | 423.09 ft² |
| 18 in. | 168 ft² + 128 ft² + 18.48 ft² | 111.59 ft² | 426.07 ft² |
| 20 in. | 170.66 ft² + 130.66 ft² + 18.78 ft² | 111.59 ft² | 431.69 ft² |
| 22 in. | 170.66 ft² + 130.66 ft² + 18.78 ft² | 111.59 ft² | 431.69 ft² |
| 24 in. | 173.33 ft² + 130.66 ft² + 19.06 ft² | 111.59 ft² | 434.64 ft² |
2×4 Rafters and 2×6 Studs
| Stud spacing | Wall area | Roof area | Total area |
| 16 in. | 165.32 ft² + 122.66 ft² + 18.18 ft² | 111.59 ft² | 417.75 ft² |
| 18 in. | 168 ft² + 122.66 ft² + 18.48 ft² | 111.59 ft² | 420.73 ft² |
| 20 in. | 170.66 ft² + 125.34 ft² + 18.78 ft² | 111.59 ft² | 426.37 ft² |
| 22 in. | 170.66 ft² + 125.34 ft² + 18.78 ft² | 111.59 ft² | 426.37 ft² |
| 24 in. | 173.33 ft² + 125.34 ft² + 19.06 ft² | 111.59 ft² | 429.32 ft² |
2×4 Rafters an 2×8 Studs
| Stud spacing | Wall area | Roof area | Total area |
| 16 in. | 165.32 ft² + 117.34 ft² + 18.18 ft² | 111.59 ft² | 412.43 ft² |
| 18 in. | 168 ft² + 120 ft² + 18.48 ft² | 111.59 ft² | 418.07 ft² |
| 20 in. | 170.66 ft² + 120 ft² + 18.78 ft² | 111.59 ft² | 421.03 ft² |
| 22 in. | 170.66 ft² + 120 ft² + 18.78 ft² | 111.59 ft² | 421.03 ft² |
| 24 in. | 173.33 ft² + 120 ft² + 19.06 ft² | 111.59 ft² | 423.98 ft² |
2×6 Rafters and 2×4 Studs
| Stud spacing | Wall area | Roof area | Total area |
| 16 in. | 165.32 ft² + 128 ft² + 18.18 ft² | 108.13 ft² | 419.63 ft² |
| 18 in. | 168 ft² + 128 ft² + 18.48 ft² | 108.13 ft² | 422.61 ft² |
| 20 in. | 170.66 ft² + 130.66 ft² + 18.78 ft² | 108.13 ft² | 428.23 ft² |
| 22 in. | 170.66 ft² + 130.66 ft² + 18.78 ft² | 108.13 ft² | 428.23 ft² |
| 24 in. | 173.33 ft² + 130.66 ft² + 19.06 ft² | 108.13 ft² | 431.18 ft² |
2×6 Rafters and 2×6 Studs
| Stud spacing | Wall area | Roof area | Total area |
| 16 in. | 165.32 ft² + 122.66 ft² + 18.18 ft² | 108.13 ft² | 414.29 ft² |
| 18 in. | 168 ft² + 122.66 ft² + 18.48 ft² | 108.13 ft² | 417.27 ft² |
| 20 in. | 170.66 ft² + 125.34 ft² + 18.78 ft² | 108.13 ft² | 422.91 ft² |
| 22 in. | 170.66 ft² + 125.34 ft² + 18.78 ft² | 108.13 ft² | 422.91 ft² |
| 24 in. | 173.33 ft² + 125.34 ft² + 19.06 ft² | 108.13 ft² | 425.86 ft² |
2×6 Rafters and 2×8 Studs
| Stud spacing | Wall area | Roof area | Total area |
| 16 in. | 165.32 ft² + 117.34 ft² + 18.18 ft² | 108.13 ft² | 408.97 ft² |
| 18 in. | 168 ft² + 120 ft² + 18.48 ft² | 108.13 ft² | 414.61 ft² |
| 20 in. | 170.66 ft² + 120 ft² + 18.78 ft² | 108.13 ft² | 417.57 ft² |
| 22 in. | 170.66 ft² + 120 ft² + 18.78 ft² | 108.13 ft² | 417.57 ft² |
| 24 in. | 173.33 ft² + 120 ft² + 19.06 ft² | 108.13 ft² | 420.52 ft² |