How Much Insulation Do I Need for a 10×12 Shed?

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.

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

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