PEB erection sequence

Before the steel arrives

A pre-engineered building goes up quickly because every piece is fabricated to fit – but only if the foundations are right and the site is ready. Before erection the erector should have the approved erection drawings, the anchor bolt setting plan, a lifting plan, an erection method statement and a delivery schedule matched to the packing lists. Crane access, laydown areas, ground bearing for cranes and elevating work platforms, and storage for cladding must be planned.

The sequence step by step

1. Survey anchor bolts and foundations. Check grid lines, anchor bolt positions, projections and top-of-concrete or grout levels against the anchor bolt plan before any steel is set. Correcting a misplaced anchor group now costs hours; discovering it with a column in the air costs days. See base plates and anchor bolts.
2. Set leveling nuts or shims to the base plate elevation, ready for grouting later.
3. Erect the first braced bay. Stand the columns of the two frames that contain the permanent bracing (or a bay designated for temporary bracing), connect the rafters, install eave struts and some purlins, and install the roof and wall bracing. Plumb and square this bay carefully – it is the reference for the whole building.
4. Erect the remaining frames. Add frames one by one, each connected to the braced bay by purlins, girts and eave struts as it goes up. Temporary guying is kept until enough secondary members connect it to the stable bay.
5. Install secondary members. Complete purlins, girts, flange braces, sag rods and endwall framing. Flange braces are important: without them the rafter and column inner flanges are unrestrained.
6. Plumb, line and tension bracing. Plumb columns and align rafters, then tension rod or cable bracing so that the frame is held in position; check that the building is square on plan by comparing diagonals.
7. Tighten bolts to snug-tight or pretension as specified on the drawings and inspect them.
8. Grout base plates once the structure is plumb and the frames are fully bolted.
9. Install sheeting – usually walls before or with the roof depending on wind exposure – with insulation, skylights and sealants.
10. Install accessories – gutters, downspouts, trims and flashings, ventilators, doors and windows.

Variations by building type

System-specific details are covered in the frame system articles, for example crane buildings.

Cladding, insulation and accessories on site

The envelope usually takes longer to install than the frames, and most leaks and appearance complaints are created during this stage. Good practice for each package:

Sheets and panels act as sails during handling: stop lifting and laying cladding when wind exceeds the limit in the method statement, and secure unfixed sheets at the end of each shift. See roof sheeting and trims and flashings for detailing rules.

Roles and responsibilities

Under the MBMA common industry practices and AISC 303, the erector is responsible for the means and methods of erection, including temporary bracing and the stability of the partially erected structure, while the building manufacturer supplies the erection drawings and, on request, guidance. In Australia AS/NZS 5131 and in Europe EN 1090-2 require an erection method statement that addresses stability at every stage. The principles are covered in site safety during steel erection, and the accuracy to be achieved in erection tolerances.

WSC erection support

World Steel provides erection drawings, anchor bolt plans, packing lists by erection sequence and, through its erection service, supervision by experienced engineers or full erection in selected markets. See erection and erection supervision.

Never remove temporary bracing until permanent bracing, secondary members and connections in the bay are complete and the engineer of record or erection engineer confirms the structure is stable.