Shed Roof Guide

A shed roof—also called a skillion or mono-pitch roof—uses one continuous sloping plane. The simple geometry can look sharply modern, work efficiently on additions and direct rain or snow toward one edge. Its apparent simplicity makes the high wall, low eave and drainage capacity especially important.

Shed roof at a glance

Defining feature	One roof plane sloping in a single direction
Main advantage	Simple structure and clear drainage direction
Main concern	Concentrated runoff and high-wall weather exposure
Common materials	Metal, asphalt shingles on adequate slopes, or membranes on low slopes
Common uses	Additions, porches, cabins and contemporary homes

Why choose a shed roof?

A single pitch avoids a ridge and can create a high interior wall for clerestory windows. The roof may be oriented for daylight, views or solar panels. On an addition, it can connect below an existing eave without reproducing the original roof shape, although the junction still requires careful design.

Advantages

• Simple, legible form with relatively few valleys.
• Potentially efficient framing for modest spans.
• Useful high wall for windows and natural light.
• One predictable edge for gutters and rainwater collection.
• Large uninterrupted plane that may suit solar arrays.

Limitations

All surface water reaches the low edge, so gutters, downspouts and discharge paths must handle concentrated flow. The high wall can face wind-driven rain and needs correct cladding and head flashing. Large roof spans or low slopes may need deeper structural members, and an addition roof can create snow or water conflicts with the main building.

Pitch and material

The covering must be approved for the designed slope. Asphalt shingles require a steep enough pitch and may need enhanced underlayment near the lower end of their range. Standing-seam metal can suit many shed roofs, while very low slopes often require continuous membranes. “It looks steep enough” is not a specification—confirm the measured pitch and product instructions.

Drainage and the low eave

Size gutters and downspouts for roof area and local rainfall. Overflow should move away from foundations and entrances. Ice can build at the eave in cold climates if insulation and air sealing allow heat to escape. Wide overhangs protect walls but increase uplift forces and structural demands.

The high-wall detail

At the top of the slope, roofing may terminate below a wall or parapet. Counterflashing, siding clearances and water-resistive layers must overlap in shingle fashion so water exits to the exterior. Sealant alone is not a durable substitute for correctly lapped materials.

Ventilation and insulation

A shed roof may have a vented attic, a compact unvented assembly or a hybrid design. The right approach depends on climate, framing depth and interior humidity. High and low vents need a continuous air path when the assembly is vented. Cathedral ceilings leave little room for errors in air sealing or insulation thickness.

Solar orientation

The single plane can make panel layout straightforward, but direction and pitch influence annual output. Structural capacity, roof warranty, attachment flashing and future reroofing access should be coordinated before installation rather than after the roof is finished.

Inspection and maintenance

• Keep the single drainage edge and downspouts clear.
• Inspect the high-wall termination and any clerestory windows.
• Watch for ponding on very low slopes or deflection between framing members.
• Check penetrations and solar attachment points after severe weather.

Cost considerations

Simple geometry can reduce framing and roofing complexity, but large spans, extensive glazing, custom metal or drainage upgrades can offset savings. On an addition, connection work and changes to the existing wall often dominate the budget.

For membrane options, see our flat and low-slope materials guide.