Project Delivery
Erection of Pre-Engineered Buildings: Steps and Safety
Erection of a pre-engineered building is the site assembly of the delivered kit on prepared foundations, beginning with a braced bay of columns and rafters, followed by secondary framing, bracing, alignment, bolt tightening and installation of roof and wall cladding, trims and accessories.
Key facts
- Foundations and anchor bolts must be checked before steel arrives.
- Erection typically starts with a braced bay to create a stable starting point.
- Temporary bracing is needed until permanent bracing and sheeting are complete.
- Bolts are installed and tightened to the method specified.
- Working at height and lifting operations require planned safety controls.
Site readiness before erection
Before erection begins, the site should have clear access for cranes and delivery vehicles, a level storage area and completed foundations. Anchor bolts are surveyed for position, projection and level against the anchor bolt plan, because errors here are expensive to correct once steel arrives.
The erector prepares a site-specific method statement and lift plan covering crane selection, lifting points, sequence, temporary bracing and safety measures.
Erecting the first braced bay
Erection normally starts in a bay that contains permanent bracing. Columns are set on the anchor bolts, rafters are assembled on the ground at their splices and lifted into place, and the first two frames are connected with purlins, eave struts and bracing.
This braced bay is plumbed, aligned and secured before additional frames are added. It becomes the stable reference for the rest of the building.
Frames, secondary members and bracing
Additional frames are erected bay by bay and connected with purlins and girts. Temporary bracing or guys hold frames stable until permanent bracing, flange braces and sag rods are installed. Bracing rods or cables are tensioned to remove slack without overstressing.
Once a section of the building is erected, alignment is checked and bolts are tightened to the method specified, for example snug-tight or pretensioned as shown on the drawings.
Installing roof and wall cladding
Sheeting starts after frames are aligned and secondary members are straightened. Roof sheets are laid in the direction that keeps side laps away from prevailing weather, with fasteners, closures and sealants installed as detailed. Standing seam roofs are seamed with the correct tools.
Wall cladding, trims, gutters, downspouts and accessories follow. Swarf is swept off the roof regularly, and protective films are removed as specified.
Safety during erection
Erection involves lifting and work at height. Controls include planned lifts, competent crane operators and riggers, exclusion zones, fall protection such as harnesses with suitable anchors, safety nets or mobile elevating work platforms, and wind limits for lifting and sheeting.
Roofs should never be walked on unsupported sheets or skylights. Translucent panels need protection or marking during construction to prevent falls.
Points to confirm before erection starts
- Anchor bolt survey results and foundation readiness.
- Erection drawings, sequence and method statement.
- Crane capacity, access and lift plan.
- Temporary bracing plan.
- Bolt tightening method and inspection.
- Fall protection and wind limits.
Frequently Asked Questions
Why does erection start with a braced bay?
A braced bay provides a stable, plumb starting point. Other frames are connected to it, which keeps the structure stable during erection.
Are temporary braces required?
Yes, until permanent bracing, purlins, girts and sheeting are installed the frames may not be stable on their own. Temporary bracing is part of the erection plan.
Can sheeting be installed in high wind?
Handling large sheets in strong wind is dangerous. The erector sets wind limits for lifting and sheeting and stops work when they are exceeded.
Engineering content is general guidance. Every World Steel building is designed by qualified engineers to the code and loads of the project.
