The steel frame is only as good as what it sits on. Foundations, anchor bolts, and site logistics are usually the owner's or local contractor's scope - but they must be prepared exactly as the steel supplier's drawings require. Most erection delays do not come from the steel; they come from foundations that were cast to the wrong dimensions, bolts set in the wrong position, or site access that was forgotten.
What the Supplier Needs from You
A site plan showing the building footprint, orientation, and finished floor level.
Soil conditions: a simple soil report or local knowledge, so the foundation can be designed or verified.
Confirm the site is level or the design accounts for the slope.
Access: how the delivery vehicles reach the site, where the crane will stand, and where the steel will be stored.
Foundation Types
Strip footings: continuous concrete strips under wall and frame lines - typical for light single-storey buildings.
Pad footings: individual concrete pads under columns - common for portal frames; the pad size follows the column load and soil capacity.
Raft slabs: a full concrete slab carrying both the frame and the floor - used on weak soils or where the floor itself is critical.
Piled foundations: where the soil is too weak for spread footings - a specialist design, only where required.
Anchor Bolt Installation - the Critical Step
The steel supplier issues the anchor bolt plan: bolt group positions, diameters, projection, and thread length.
Bolts are set with a template or jig, checked before concrete is poured, and re-checked after the pour.
Tolerances follow the drawings (typically ±3–5 mm in plan); any deviation beyond tolerance is corrected with the supplier's approval, never by bending bolts.
For export projects, confirm who supplies the anchor bolts - many suppliers ship the fixing set with the steel, and the foundation contractor must have it before casting.
Site Logistics
|
Item |
What to Prepare |
|
Delivery access |
Wide, hard access for trucks; check turning radius and overhead clearance |
|
Crane position |
Hard standing, safe distance from the frame, capacity matched to the heaviest member |
|
Steel storage |
Dry, level area; bundles on dunnage; cladding kept covered and protected |
|
Workforce |
Local erectors briefed on the erection drawings and the safety plan |
|
Tools and consumables |
Torque wrenches, welding equipment, grout, and fixing materials on site before erection starts |
Buyer's Rule
Send the anchor bolt plan to the foundation contractor in writing, before the concrete is ordered. Check the bolt positions yourself or have the site supervisor check them, because re-drilling concrete or re-casting footings costs more than the steel it supports. A well-prepared site is the difference between an erection that takes two weeks and one that takes two months.