Steel Structure
Q235/Q355 Grade Steel
H-Shaped Steel
C/Z Section Steel
Insulation Panel (EPS/PU/Rock Wool), Metal Sheet
Crane, Drainage Pipe, Door, Window
Over 25 Years
30 Days After Receiving the Deposit
T/T, L/C, PayPal
The double slope warehouse — also called a gable roof warehouse — is a steel building whose roof is formed by two pitched planes meeting at a ridge. Canglong fabricates it as a Q355B steel frame kit with a 10°–15° roof slope, clear spans up to 60 m, and hot-dip galvanized or aluminum-zinc coating (ISO 1461) as standard.
The double-pitch geometry is not cosmetic. Two equal slopes drain rainwater in both directions, which roughly doubles the effective drainage of a single-slope roof of the same span. The symmetrical frame balances wind uplift between both eaves, and the ridge gives snow a single, predictable shedding path. These are the three engineering reasons the double slope is the most common warehouse roof form worldwide.
Standard kit ratings: 62 m/s wind resistance (typhoon zone), 1.5 kN/m² snow load, and continuous operation at −45 °C for Arctic-region projects. The frame is fully bolted on site — no field welding — and ships as a prefabricated warehouse kit. Lead time is 30 days after deposit, with a 72-hour engineering response for quotation and structural review.




A double slope warehouse is a single-storey steel building defined by its roof geometry: two pitched surfaces of equal angle meet at a center ridge, forming the classic gable profile. The pitch of 10°–15° is deliberately moderate — steep enough to shed rain and snow quickly, shallow enough to keep the steel weight per square meter low.
Within the same portal frame family, the double slope is the configuration you choose when a project needs dependable drainage, uniform headroom, or roof-mounted equipment. It differs from a single slope (mono-pitch) warehouse in three measurable ways: drainage capacity roughly doubles, wind loads distribute symmetrically between both walls, and the ridge line provides a natural mounting line for ridge ventilators, skylights, and photovoltaic arrays.
| Primary frame | Welded H-section portal frames, fixed or pinned base, Q235B/Q355B steel |
| Secondary framing | Cold-formed C/Z purlins and girts, hot-dip galvanized |
| Roof/wall system | EPS, PU, or rock wool sandwich panel (50–150 mm), or corrugated steel sheet |
| Bracing | X-type angle or round-bar bracing, tie rods, knee braces |
| Connections | High-strength bolts — fully bolted field assembly, no welding on site |
| Accessories | Ridge ventilator, gutter and downpipe, sliding/rolling doors, windows, optional overhead crane |
| Clear span | 15–60 m | Custom per bay layout |
| Eave height | 4–12 m | Higher eaves for racking and fork lift clearance |
| Roof slope | 10°–15° standard | Up to 25° for high snow-load regions |
| Bay spacing | 6–8 m | Adjustable to cladding module |
| Steel grade | Q355B (Q235B for light duty) | Q390B available on request |
| Column/beam section | Welded H-section (variable cross-section) | — |
| Purlin | C/Z section, galvanized | — |
| Coating | Hot-dip galvanized to ISO 1461, or aluminum-zinc | Paint systems for indoor frames |
| Wind load | Up to 62 m/s (typhoon zone) | Calculated to project wind map |
| Snow load | Up to 1.5 kN/m² | Higher loads recalculated per code |
| Seismic | Per local code | GB 50011 / AISC 341 / Eurocode 8 |
| Design standard | GB 50017, AISC, Eurocode 3, AS/NZS 1170 | Engineer-stamped drawings |
Two slopes drain to two eave gutters, so the roof sheds heavy rainfall roughly twice as fast as a single-pitch roof of the same span. The 10°–15° pitch stays above the minimum self-cleaning slope, which prevents ponding and reduces the leak risk that flat roofs face under monsoon or typhoon rain.
Wind uplift on a gable roof is shared evenly by both columns, which removes the one-sided overturning moment a mono-pitch roof creates. The standard kit is rated to 62 m/s wind — the typhoon band — with bracing sized from the site wind map rather than a generic template.
Snow slides toward both eaves along the slope instead of accumulating on a single long run. The frame is calculated for 1.5 kN/m² ground snow load and has been specified for −45 °C projects, where the roof slope is raised to 20°–25° so snow cannot pile against the ridge.
The ridge is a natural mounting line for ridge ventilators, which pull hot air out in warehouse environments, and for translucent skylight strips that cut lighting cost during the day. The 10°–15° pitch is also close to the optimum angle for fixed photovoltaic panels — the kit can carry a roof-mounted PV array up to 120 kW.
Canglong fabricates the double slope warehouse to international design codes — GB 50017, AISC, Eurocode 3, or AS/NZS 1170 as the project requires — and the factory holds ISO 9001 quality management and CE certification. Hot-dip galvanizing is performed to ISO 1461 with the coating thickness specified in the contract, and third-party inspection (SGS, BV, or TÜV) can be arranged before loading.
The double slope warehouse is a general-purpose storage building. Typical projects include e-commerce fulfillment centers, agricultural produce and equipment storage, light manufacturing bases, and cold chain hubs when fitted with an insulated envelope. For a scenario-specific layout — grain storage, cold storage, or factory use — see the corresponding application pages for the full system design.
Every frame is cut, welded, shot-blasted, and galvanized inside our Henan factory — over 100,000 m² of production area with an annual output above $100 million. Standard delivery is 30 days after deposit; the building ships as a bolt-together kit in 40′ open-top or 40′ HQ containers with a packing list per frame. Installation is handled by our teams in 30+ countries, or by local crews guided by our engineers with full erection drawings.
Standard pitch is 10°–15°. For regions with heavy snowfall or extreme rainfall, we recalculate the frame for 20°–25° slopes. Tell us your site wind and snow data and we will size the slope in the structural design.
Up to 60 m with Q355B welded H-section frames, subject to local wind and snow loads. The cost-optimal span for most storage projects is 18–36 m, where steel tonnage per square meter is lowest.
Main frames are Q355B (or Q235B for light duty); secondary members are galvanized C/Z sections. Hot-dip galvanizing follows ISO 1461 — coating thickness is agreed in the contract, and aluminum-zinc coating is available for coastal environments.
Choose a double slope when the site has heavy rain, snow, or typhoon wind, or when you need uniform headroom and a ridge line for ventilation. Choose a single slope for low-cost lean-to extensions or when one high wall is needed for crane or large door access. See our single slope warehouse page for the comparison.
Yes. An overhead crane beam can be integrated into the frame with the crane capacity and lift height specified before fabrication, so the frame sections are sized for the crane loads from the start.
Standard lead time is 30 days after deposit. The kit is loaded into 40′ open-top or 40′ HQ containers, and we provide the container load plan, erection drawings, and optional on-site installation support.
Send your building size, location, and intended use — or just your site wind and snow data — and our engineers will reply with a structural layout, weight estimate, and quotation within 72 hours. Free 3D design is included with your first inquiry.
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Canglong projects cover more than 120 countries and regions around the world, providing one-stop steel structure building solutions from design to installation.