Lead time depends on the project size and complexity. For a standard portal frame warehouse between 1,000-5,000 sqm, expect 25-35 days for fabrication after design approval. Larger or custom projects (over 5,000 sqm or multi-story) typically require 40-55 days. These timelines cover steel fabrication only—foundation work, shipping, and erection are additional. We provide a detailed project schedule at the quotation stage showing all phases from design to handover.

We use Q235B and Q345B as standard grades for primary structural members (columns, beams, purlins). Q345B is specified for main frames on spans exceeding 18m or buildings in high wind/snow load zones. Secondary members (girts, bracing, eave struts) typically use Q235B. All steel is sourced from certified mills with mill test certificates provided. For export projects requiring international standards, we can supply equivalent grades: S235JR/S355JR (EN standard) or A36/A572 Gr.50 (ASTM standard).

Yes. Every project is engineered to site-specific loading conditions. Provide us with your project location and we calculate design loads per the applicable code—Chinese GB 50009, ASCE 7 (US), EN 1991 (Europe), or AS/NZS 1170 (Australia). We have delivered projects rated for wind speeds up to 200 km/h (Category 4 cyclone regions in Australia and the Pacific Islands) and Seismic Zone IV conditions. Our engineering team uses PKPM and SAP2000 for structural analysis with full calculation reports available for your review.

Foundation choice depends on soil conditions, building loads, and local frost depth. For standard steel warehouses on competent soil (bearing capacity above 150 kPa), isolated pad footings at each column location are the most economical option. Typical pad sizes range from 1.2m x 1.2m to 2.0m x 2.0m depending on column reactions. For buildings with overhead cranes above 10 tons, we recommend continuous strip footings along the crane runway columns to distribute the dynamic loads. In areas with weak soil (bearing capacity below 100 kPa), driven piles or bored piles with pile caps become necessary. We provide foundation design drawings and anchor bolt layouts as part of our engineering package. Foundation work typically accounts for 12-18% of total project cost and takes 2-4 weeks depending on size. Start foundation work while steel is being fabricated to keep your timeline on track.

Erection speed depends on building size, complexity, and crew experience. As a benchmark: a standard 1,000 sqm portal frame warehouse (5-6 bays at 6m spacing, 10m eave height, no crane) takes 10-14 working days with a 6-person crew and one 25-ton mobile crane. A 5,000 sqm building of similar configuration takes 30-40 days. Multi-story buildings or structures with mezzanines, cranes, and complex cladding patterns take longer. Cold-formed steel buildings (for low-rise residential or commercial) erect faster since members are lighter, often 5-7 days for a 200 sqm single-story structure. We supply detailed erection drawings with numbered members and bolt lists. Each connection is pre-designed for site bolting only, no welding needed on site. We offer erection supervision or full installation service depending on your project location and preference.

Our standard structural steel grade is Q345B (equivalent to S355 / ASTM A572 Grade 50) for primary frames and Q235B (equivalent to S235 / ASTM A36) for secondary members like purlins, girts, and bracing. Higher grades (Q390 or Q420) are available for heavy-load applications where reducing member weight matters for shipping. For corrosion protection, our standard system is Sa 2.5 blast cleaning followed by one coat of epoxy zinc-rich primer (75 microns DFT) and one coat of epoxy intermediate (125 microns DFT). For coastal or high-humidity environments, we add a polyurethane topcoat for a total system of 250+ microns. Hot-dip galvanizing (HDG) per ISO 1461 is available for purlins, girts, and other light-gauge members where long-term maintenance access is limited. All coating work is tested per ISO 19840 with DFT readings documented in our quality report.

For standard single-story warehouses under 12m eave height, isolated pad footings (also called spread footings) are the most cost-effective foundation type. Each column base sits on a reinforced concrete pad typically 1.5m x 1.5m x 0.6m deep, connected by grade beams along the perimeter. For sites with poor soil bearing capacity (below 100 kPa), we recommend driven piles or bored piles with pile caps. Raft foundations are rarely needed for steel structures since the building weight is relatively low — a 1,000 sqm portal frame warehouse weighs approximately 35-45 tons total, distributed across 12-16 column points. We provide anchor bolt layout drawings with exact coordinates, bolt diameters (typically M20 or M24 for warehouses), and projection heights. Foundation work is usually handled by local contractors using our civil drawings. Tolerance for anchor bolt placement is +/- 3mm — anything beyond that requires field correction with base plate hole enlargement.

We design to local wind codes — whether that’s ASCE 7 (US), AS/NZS 1170.2 (Australia), BS 6399 (UK), or Chinese GB 50009. For high wind regions (basic wind speed above 45 m/s or 160 km/h), several design modifications apply: increased column and rafter sections (typically 20-30% heavier than standard), closer purlin spacing (reduced from 1.5m to 1.0-1.2m), additional bracing bays, and upgraded connection bolt grades from 8.8 to 10.9. Cladding fastener spacing also decreases in corner and edge zones where wind suction peaks. For cyclone-rated buildings (Region C/D in Australian standards), we use specific connection details — holding-down bolts sized for net uplift forces, apex connections designed for load reversal, and fly bracing on inner flanges. We’ve supplied buildings to the Philippines, Pacific Islands, and Northern Australia rated for Category 4 cyclone conditions. Each project gets a site-specific wind analysis — we don’t use generic templates for high-wind designs.

For soft soils (bearing capacity below 100 kPa), we typically specify one of three foundation systems based on building size and soil report. Isolated pad footings with tie beams work for small buildings under 1,000m² where the structural loads are moderate. For medium warehouses, a continuous strip footing along the column lines distributes load more evenly. In very poor soils (waterlogged or compressive), we switch to driven concrete piles at each column base, with the pile cap carrying the anchor bolts. Our structural team reviews your geotechnical report (or recommends a testing scope if you don’t have one) and specifies the most cost-effective solution. Foundation engineering is included in our turnkey quotes at no extra cost—it’s where projects fail when done incorrectly, so we keep it in-house.

Yes, and this is one of the main advantages of steel frame over concrete or masonry. We design expansion provisions into every project when the client mentions future growth plans. The connection detail at the expansion end uses a bolted splice plate instead of a welded end frame, so the future bay simply bolts on. We’ve delivered several projects where clients added 2-4 bays after 12-18 months. Cost per square meter on the extension is typically 8-12% lower than the original building since the end wall and utilities already exist. We archive all production drawings, so matching the existing profile and connections is straightforward even years later.

Standard package: one coat alkyd primer (75 microns DFT) plus one coat alkyd topcoat (75 microns DFT), total 150 microns. Color is RAL-coded, you pick from the full RAL Classic chart. This suits most inland environments with normal humidity. For coastal, tropical, or industrial sites within 5km of salt water or chemical plants, we specify the heavy-duty system: zinc-rich epoxy primer (80 microns) plus epoxy intermediate coat (150 microns) plus polyurethane topcoat (60 microns), total 290 microns DFT. Expected maintenance interval is 15-20 years with the heavy system. Hot-dip galvanizing is available as an upgrade for critical members at roughly $180-220/ton additional. All surface prep is done by blast cleaning to SA 2.5 standard before coating.

We have no strict MOQ for steel structure projects. We regularly handle single-building orders starting from 200 sqm floor area (approximately 8-12 tons of steel). However, ordering a single small building means fixed costs like engineering, shop drawings, and shipping container space are spread over fewer tons, making the per-ton price higher. For orders below 15 tons, expect a 10-15% premium compared to our standard pricing. The sweet spot for cost efficiency starts at 30+ tons, which typically equals one 40ft container of steel. If you’re planning multiple buildings across different sites or phases, consolidating them into one production order saves 5-10% through batch fabrication efficiency and shared engineering work. We handle split shipments to different destinations from the same production run without issues.

Our quality control process covers three stages: incoming material inspection, in-process checks, and final inspection before shipping. For incoming steel, we verify mill test certificates against order specifications and perform random thickness/grade spot checks. During fabrication, welders hold AWS D1.1 or EN ISO 9606 certifications, and all critical welds (moment connections, base plates, crane brackets) receive ultrasonic testing (UT) per EN ISO 17640 with a minimum 10% inspection rate. Visual inspection covers 100% of welds. Dimensional checks follow tolerances in AISC 303 or EN 1090-2 Execution Class 2. Before shipping, we conduct a full assembly check (trial erection) of representative frames to verify fit-up. Documentation package includes: material certificates, weld inspection reports, coating thickness records (DFT readings per ISO 19840), dimensional inspection reports, and packing lists with member marking drawings. Third-party inspection (SGS, Bureau Veritas, TUV) is available at buyer’s cost if required by your project specifications or financing institution. Our factory holds ISO 9001:2015 and ISO 3834-2 welding quality certifications.