The single slope shed roof, also called a shed roof or skillion, offers a simple, modern roofing option for sheds, garages, and additions. This guide covers design choices, materials, structural considerations, and estimated costs to help readers plan a durable and code-compliant roof.
| Feature | Typical Range / Note |
|---|---|
| Roof Pitch | 1:12 To 6:12; Common: 2:12–4:12 |
| Materials | Metal Panels, Asphalt Shingles, TPO, EPDM |
| Estimated Cost | $6–$18 Per Sq Ft Installed (Varies With Material & Region) |
| Drainage | Single Downspout Or Gutter Run Along Low Edge |
| Best Use | Modern Sheds, Lean-Tos, Tiny Homes, Garage Additions |
What Is A Single Slope Shed Roof
A single slope shed roof is a roof plane that tilts in one direction from a high edge to a low edge, creating a clean, minimalist profile. Its simple geometry reduces framing complexity and material waste compared to gable roofs, which is why it is popular for small structures and contemporary architecture.
Advantages And Limitations
Advantages:
- Cost-Efficient — Fewer rafters and simpler framing reduce labor and material costs.
- Easy Drainage Management — Water and snow shed toward one side for concentrated guttering.
- Modern Aesthetic — Suits contemporary designs and allows for high windows on the tall side.
- Solar-Ready — One large plane simplifies photovoltaic panel layout and improves tilt uniformity.
Limitations:
- Wind Exposure — Large, single planes can catch wind and require robust anchoring in high-wind zones.
- Snow Loads — In heavy-snow regions, design must account for accumulation at the low edge or use steeper pitch.
- Limited Attic Space — Little to no loft area compared with pitched roofs.
Choosing The Right Pitch
Pitch determines drainage, appearance, and material compatibility. A 2:12 To 4:12 pitch is common for sheds, balancing runoff with a low-profile look. Lower slopes (1:12–2:12) work well with metal panels and membrane roofing; steeper slopes (4:12+) allow asphalt shingles and provide faster runoff in snow-prone areas.
Material Options And Performance
Material choice impacts longevity, maintenance, and cost. Metal roofing is the most popular choice for single slope shed roofs due to durability, light weight, and low maintenance.
- Metal Panels — Standing seam or corrugated panels offer long life (30+ years) and excellent water shedding.
- Asphalt Shingles — Suitable for pitches above 3:12; lower cost but shorter lifespan and more maintenance.
- Single-Ply Membranes (TPO/EPDM) — Good for low slopes, seamless installation, and heat/UV resistance.
- IBC/Cedar Shakes — Rare for single slope sheds due to weight and maintenance; typically avoided.
Structural Framing And Support
Framing must resist vertical loads and lateral forces. Typical methods include rafters, gable truss modifications, or engineered roof joists. Beams and posts on the low side may need reinforcement to handle cantilevered loads and wind uplift.
Common framing elements:
- Rafters Or Joists — Spaced per load tables or engineered design, often 16″ or 24″ on center.
- Ridge Or High-Beam — A top plate or header supports the high edge and transfers loads to walls.
- Blocking And Collar Ties — Prevent racking and distribute wind uplift forces.
Water Management And Flashing
Effective drainage prevents leaks at the low edge and wall intersections. Install continuous gutters on the low edge and ensure counter-flashing where the roof meets vertical walls.
- Drip Edge — Metal drip at the low edge prevents water from wicking under roofing.
- Wall Flashing — Step flashing where roof meets a taller wall, plus kick-out flashing to route water into the gutter.
- Underlayment — Synthetic or felt underlayment adds a secondary barrier for shingles or metal.
Ventilation And Insulation Strategies
Proper ventilation and insulation maintain thermal comfort and prevent condensation. Because a single slope roof often has limited attic space, careful placement of vents and insulation is essential.
- Intake Vents — Soffit vents on the low side where applicable provide fresh air intake.
- Exhaust Vents — Ridge vents are not possible; use continuous soffit-to-gable vents, roof vents, or cupolas at the high edge.
- Insulation — Spray foam or rigid board insulation under the roof deck is common to reduce thermal bridging.
Code, Permits, And Local Considerations
Building codes vary by jurisdiction. Local codes will set minimum wind and snow load requirements, fastener schedules, and allowable spans for rafters and beams.Permit requirements typically cover structural plans, material specifications, and flashing details.
To comply:
- Consult Local Building Department for required documents and inspections.
- Use Certified Plans Or Engineered Drawings for larger spans or exposed sites.
- Follow Manufacturer Guidelines for roofing material attachment and underlayment.
Cost Estimates And Budgeting
Costs depend on size, material, complexity, and labor rates. Typical installed costs range from about $6 to $18 per square foot for most single slope shed roofs.
| Material | Installed Cost Per Sq Ft |
|---|---|
| Corrugated Metal | $6–$10 |
| Standing Seam Metal | $10–$18 |
| Asphalt Shingle | $6–$12 |
| TPO/EPDM Membrane | $8–$15 |
Extra costs to budget for include gutters, flashing, insulation, and structural reinforcements. Labor can vary widely; obtaining multiple bids ensures competitive pricing.
Step-By-Step Installation Overview
This high-level sequence helps readers understand the process; professionals should follow detailed construction plans. Key steps include framing, sheathing, underlayment, flashing, roofing material installation, and guttering.
- Site Preparation — Ensure walls, plates, and supporting beams are level and securely fastened.
- Framing — Install rafters or joists to achieve the designed slope and fastening schedule.
- Sheathing — Apply roof deck (OSB or plywood) and fasten per code.
- Underlayment & Ice Barrier — Install synthetic underlayment and ice/water shield where required.
- Flashing — Fit step and kick-out flashing at wall intersections; install drip edge on low edge.
- Roofing Material — Lay metal panels, shingles, or membrane per manufacturer instructions.
- Gutters & Downspouts — Attach continuous gutters along the low edge and route water away from the foundation.
Common Design Variations And Applications
Single slope roofs adapt to many uses. Lean-To Sheds, Modern Garages, Sunrooms, And Tiny Homes Frequently Use This Roof Type.
- Mono-Pitch Addition — Matches existing rooflines or creates a deliberate offset for windows.
- Reverse-Shed — Tall side faces the street for a dramatic facade and clerestory windows.
- Multi-Panel Shed Roof — Combines several single slopes at different heights for visual interest.
Maintenance Tips For Longevity
Routine maintenance preserves performance and extends life. Inspect flashing, fasteners, and gutters annually, and remove debris to prevent ponding and corrosion.
- Check Fasteners — Tighten or replace loose screws on metal panels.
- Clear Gutters — Prevent overflows that can damage siding and foundations.
- Re-seal Flashing — Reseal exposed flashings and membrane seams as needed.
When To Consult A Professional
Certain situations require expert input. Consult an engineer or licensed contractor for long spans, heavy snow zones, complex attachments to existing structures, or rooftop equipment loads.
- High Wind Or Seismic Areas — Structural calculations ensure uplift resistance.
- Large Solar Installations — Verify roof framing capacity and attachment methods.
- Unusual Geometry — Complex intersections and penetrations need precise flashing details.
Resources And Further Reading
Reliable sources include local building codes, manufacturer installation guides, and professional associations. Consult product technical sheets and the International Building Code (IBC) or local amendments for load and fastening requirements.
- FEMA — Guidance on wind and flood considerations
- International Code Council (ICC) — Building code resources
- National Roofing Contractors Association (NRCA) — Best practices for roofing materials