Insulation for a 10x12 Shed
Batts and bags for a 10 x 12 ft shed, counted bay by bay between the studs and rafters, for the walls, both gables and the roof.
- 10 x 12 ft shed
- Counted by bay
- 16 or 24 in framing
- Walls, gables and roof
Your estimate
Kraft batts, 15 in wide for 16 in framingwalls and roof
R-13, 15 x 93 in
R-19, 15 x 93 in
Counts bays between framing members, not square feet, because a batt fills one bay whatever the bay's height. Bag counts are Johns Manville kraft batts; check the label of the brand you buy.
A 10 x 12 ft shed with 7 ft walls framed 16 in on center has 31 stud bays once the 4 ft door is taken out, so the walls take 31 batts of R-13: 3 bags of Johns Manville 15 x 93 in kraft batts at 11 to a bag. Insulate the roof as well and add both gables and 18 rafter bays, for 4 bags of R-13 and 2 bags of R-19 in all. Counting by bay rather than by square foot matches how batts go in: one batt fills one bay, whatever its height.
Why count bays instead of square feet
A 93 in batt fills one stud bay of a wall up to about 8 ft. On a 7 ft shed wall you cut each batt short, and the offcut is too short to be much use elsewhere. A square-foot estimate would assume those offcuts get used, and come up a bag or so short.
At 24 in framing there are fewer bays, and the 23 in wide batts cover more per bag: the same shed takes 2 bags for the walls and gables and 2 for the roof.
Insulating the roof of a shed
- R-13 fits 2x4 rafters. R-19 batts are 6.5 in thick, so in 5.5 in deep 2x6 rafters they compress slightly; Johns Manville rates that at about R-17 to R-18.
- Leave an air gap under the roof sheathing if the roof is vented, with baffles at the eaves.
- Both gable triangles together fill one width x rise area, the same way they are counted for drywall.
Frequently asked questions
Primary references
Manufacturer and industry guidance used to check this article.
- Fiberglass insulation manufacturers fact sheet, batts per bagJohns Manville
- Premier Pro Ranch shed specifications, sidewall height and framingTuff Shed
Product instructions, tested assemblies and local code take priority over general guidance.