Gambrel vs Gable Shed: Loft Room, Cost, Framing

Last updated October 19, 2026

Gambrel vs gable shed: on a 12 ft deep shed, a gambrel (barn-style) roof gives up to about 62 in of loft clear height, a 6/12 gable about 26 in. The gable has fewer cuts, about a quarter less roof to cover and a peak 3 ft lower, so it is the simpler, cheaper build.

Gambrel vs gable shed at a glance

All three columns are for a shed 12 ft deep (the rafter span) and 16 ft long, with 94 1/2 in walls, 2×4 rafters and a storage loft of 2×6 joists and 3/4 in plywood on the top plates. As in our shed loft height guide, heights are measured from the inside face of the walls, and the gables lose about 1 1/2 in at the center to the ridge board. The gambrel uses the classic layout: four equal rafter pieces per truss, joined at 45 degree bends, so the lower slope is about 29/12 and the upper slope about 5/12.

On a 12 ft deep shed	Gable 6/12	Gable 12/12	Gambrel (classic layout)
Clear height at the peak, above the loft floor	About 26 in	About 61 in	About 62 in
Loft width with 3 ft or more clear	None	About 52 in	About 102 in
Loft width with 4 ft or more clear	None	About 28 in	About 69 in
Peak above the shed floor, roughly	About 11 ft	About 14 ft	About 14 ft
Roof surface, both sides, no overhang	About 215 sq ft	About 272 sq ft	About 294 sq ft
End wall area above the plates, each end	About 18 sq ft	About 36 sq ft	About 51 sq ft
Framing per rafter pair or truss	2 rafters and a tie	2 rafters and a tie	4 rafter pieces, a bottom chord or tie, 5 gusset joints (knees, peak, heels)

What we checked: gable heights match our loft height guide and plan generator; gambrel figures are our arithmetic and can move an inch or two with rafter depth and heel detail. Shingle slope limits come from the Asphalt Roofing Manufacturers Association steep-slope guide and its lower-slope guide. The wind notes draw on the Building America Solution Center guide to hip and gable roofs. Headroom uses the inside span; roof and end wall areas use the 12 ft outside size. Loft joist sizing points to the American Wood Council span calculator.

What is the difference between a gambrel and a gable roof?

• Gable roof: two straight slopes meet at a ridge. Each end wall carries a triangle of framing and siding up to the peak.
• Gambrel roof: each side has two slopes, a steep lower one and a flatter upper one, which meet at a bend called the knee. Most shed gambrels are built as trusses with plywood gussets at the joints.

How much more loft space does a gambrel give?

More usable floor, not more peak height. On a 12 ft span, a 12/12 gable and a classic gambrel both reach about 5 ft clear at the peak; the shape under it differs.

Under a 12/12 gable, the clear height drops 1 in for every inch you move toward a wall; under a 6/12 gable it drops 1/2 in. Under a gambrel, the lower slope climbs almost straight up. About 20 in in from the inside of the wall, the underside of the roof is already about 4 ft above the plates. That is why the gambrel gives about 102 in of loft width with 3 ft or more clear, where the 12/12 gable gives about 52 in.

Neither is a room you stand up in on a 12 ft span, but about 5 ft is enough to kneel, sit and reach shelves along the knee walls. A 6/12 gable, the pitch most of our plans use, gives about 26 in: a strip for bins and long items.

Can the loft floor carry real storage?

Only if it is sized for it. A loft across a 12 ft deep shed spans about 11 1/2 ft between the walls, a long reach for a 2×6. Size them for the span, spacing, grade and stored weight in the American Wood Council span calculator, or have a qualified person do it.

In a gambrel truss the bottom chord often doubles as the loft joist and the tie that keeps the walls from spreading. That works only when the truss is designed for both jobs, so never deck over a chord sized only as a tie.

Plan the way up before you frame: a ladder or pull-down stair opening goes between trusses or gets headered as your plan or a qualified person draws it, never by cutting a chord. An end wall loft door needs its own header.

Is a gambrel shed more expensive to build?

Usually, yes. We give quantities, not dollars, since we have not priced a gambrel list.

• Roof materials. A gambrel on a 12×16 floor has about 37 percent more roof surface than a 6/12 gable, so more OSB, underlayment, drip edge and shingles. Each knee also needs trim or flashing.
• Truss lumber. On a 16 ft long shed at 16 in on center there are 13 trusses or rafter pairs. The gambrel adds 26 rafter pieces and, with gussets at both knees, the peak and both heels, 65 gusset joints, or 130 plywood plates with one on each face.
• End walls. Each gambrel end has about 51 sq ft of wall above the plates, against about 18 sq ft on a 6/12 gable. That is roughly one extra siding sheet per end.

For a gable baseline, our shed cost guide walks through a 10×12 list as an estimate; costs vary by region and lumber prices.

Which is easier to frame?

Gable. You lay out one pattern rafter with a plumb cut at the ridge, a birdsmouth at the wall and a tail cut, test it on the walls, then copy it. Our gable vs lean-to vs hip roof guide covers gable framing.

Gambrel. Most builders snap the full truss shape on the shed floor and screw blocks along the lines to make a jig. On the classic layout each piece gets a 22.5 degree cut at the knee and peak ends. The heel, where the steep lower piece lands on the wall, needs its own detail: a seat cut, a heel gusset tying it to the bottom chord, or both, as your plan draws it. Gussets go on both faces, glued and fastened on the plan’s schedule. Build every truss in the same jig so they match.

Points that trip people up:

• Guessing the gussets. The knee joints carry the roof, so plywood thickness, gusset size and fasteners belong in the plan.
• Cutting the chord for headroom. It holds the walls in. Removing it is a redesign for a qualified person.
• Setting tall trusses alone. A truss 6 ft tall and 12 ft wide needs a helper and bracing from the first one on.

Shingles, snow and rain on each roof

The gambrel’s lower slope is the hard part to roof. On the classic layout it is about 67 degrees, or about 29/12. ARMA treats 21/12 as the steepest slope for normal shingle application and says steeper roofs need the shingle maker’s steep-slope method, which often means extra nails per shingle and hand sealing the tabs with roof cement. Read the wrapper before you buy.

Many barn-style sheds skip the problem with metal roofing panels on the steep slope; follow that maker’s install guide for the slope and trim.

The upper slope, about 5/12, is in normal shingle range. ARMA’s lower-slope guide calls for extra underlayment only below 4/12, so one layer is typical there. A 6/12 gable needs no special method on either side.

Snow slides off the steep lower slopes quickly and lands near the wall, so keep doors and paths out from under them. Rafter size, spacing and gussets matter most, so follow the plan and check your local permit office for the snow load where you live.

Water runs fast off the upper slope onto the steep one, so lap the underlayment well over the knee and trim or flash the bend.

Venting and insulating each roof

A gable is easy to vent: gable-end vents high in each triangle, or soffit vents with a ridge vent. Our shed ventilation guide covers sizing and placement.

A gambrel loft fills most of the space under the roof, so plan the airflow path. Soffit vents at the eaves, a ridge vent at the peak and vent baffles that keep a gap open past the knee keep air moving under the sheathing. End wall vents help too.

If you insulate a gambrel loft, keep about a 1 in air gap under the roof deck on both slopes, or condensation can collect under the steep lower slope. That leaves only about 2 1/2 in for insulation in a 2×4 rafter, and furring the rafters deeper eats loft headroom. Our winterizing guide has more on moisture in sheds.

Which holds up better in wind?

Neither is the strongest wind shape. The Building America Solution Center notes that, all else being equal, hip roofs see smaller wind pressures than gable roofs. A gambrel has the same kind of flat end wall as a gable, only taller and wider: about 51 sq ft above the plates on our 12 ft example, against 18 sq ft on a 6/12 gable.

Brace the end walls, put a hurricane tie at every truss or rafter, fasten the knee gussets as drawn, and anchor the shed as your plan shows. If you live in a high-wind area, check your local permit office for wind rules before you choose a design.

How tall is a gambrel shed?

On 94 1/2 in walls its peak sits about 6 ft above the plates, roughly 14 ft above the shed floor, the same as a 12/12 gable. A 6/12 gable peaks about 3 ft above the plates, near 11 ft.

Add your floor frame, foundation and roofing, since height is often measured from the ground. Many towns limit accessory building height and measure it in different ways, so check your local permit office before you settle on either one.

Which should you build?

• Pick a gambrel for a real storage loft above a workshop or mower bay, or for the barn look, if you are ready for truss jigs, steep-slope shingling and a taller shed.
• Pick a gable for the simplest framing, less roof to cover and a lower peak. For more gable loft room, go deeper, since the span sets the height, or steeper; our shed roof pitch guide shows how pitch changes rafter length and peak height.

3DSHEDPLANS sells gable, lean-to and hip roof plans. We do not sell a gambrel plan.

Plans that fit

Each 3DSHEDPLANS plan is a $19.99 PDF with 3D step images, step by step instructions and a full material list. If you choose a gable, these deeper spans give the most room overhead.

• 16×20 gable shed plan: a 16 ft span, the deepest in our gable line, with about 36 in under the ridge at 6/12.
• 12×16 gable shed plan V2: a 12 ft span with a 78 in double door for long items, about 26 in of loft clear height.
• 12×20 gable shed plan: the same 12 ft span with 4 ft more length for a longer loft strip.
• 12×12 gable shed plan: the smallest footprint with a 12 ft span and the same 26 in loft height.

See the drawings first with the free 12×12 gable shed plan PDF, compare every size on our gable shed plans page, or browse all roofs on the shed plans page.

Frequently asked questions

Is a gambrel shed more expensive than a gable shed?

Usually, yes. On a 12×16 floor our worked numbers give a gambrel about 37 percent more roof surface than a 6/12 gable, so more sheathing and shingles, plus two extra rafter pieces and three gusset joints on every truss. Each end wall also carries almost three times the siding above the plates.

How much loft space does a gambrel shed have?

On a 12 ft deep shed with a classic gambrel, our worked numbers give about 62 in of clear height at the peak above a loft floor, and a strip about 102 in wide with at least 3 ft clear. A 6/12 gable on the same span gives about 26 in at the peak.

What are the downsides of a gambrel roof?

More pieces and angled cuts, more roof area to sheathe and shingle, a taller shed, and a steep lower slope that needs the shingle maker's steep-slope method. The tall end walls also catch more wind, so bracing and tie-downs matter.

Is a gambrel roof good for snow?

The steep lower slopes shed snow quickly, but the flatter upper slopes hold it about as long as a 5/12 gable. Rafter size, spacing and gussets matter more than the shape, so follow your plan and check your local permit office for the snow load where you live.

Is a gable or gambrel shed easier to build?

A gable. Each rafter has a plumb cut, a birdsmouth and a tail cut, and you copy a tested pattern. A gambrel truss has four pieces with angled joints, plywood gussets and a heel detail at each wall, so most builders make a full-size jig on the floor first.