Planning Inspection of Roof-Support Steel Before Refurbishment

Start with the decision and the building records

Define the question the inspection is meant to inform. Is the project investigating visible corrosion, documenting the condition of members exposed during a strip, checking a particular connection, or assembling evidence for a proposed change in roof use or loading? The answer affects which areas matter, the access needed and who must review the findings. A structural steel inspection can document selected steelwork, while design capacity and suitability remain matters for the responsible engineering review.

Gather available structural drawings, specifications, previous condition reports, repair records and photographs before site work. Mark up the roof plan with gridlines, member labels, known leaks, ponding, plant supports, penetrations and locations where coatings have failed. Where records are incomplete, note that uncertainty rather than assuming the installed arrangement matches an old drawing.

Confirm the building’s current and proposed use, any planned equipment or service loads, and the refurbishment sequence with the project team. Those details help the engineer set the information required; they do not imply that a visual or NDT inspection alone can establish load capacity.

Map the load path and likely deterioration

A roof frame is a system, not a collection of isolated rusty spots. Depending on the building, the inspection plan may need to distinguish purlins spanning between rafters or trusses, primary rafters, bracing, cleats, bolts, welds, bearing points and supports. Record member marks and grid references so a finding can be located again and considered in relation to the surrounding framing.

Corrosion often concentrates where moisture is retained or protective coating is damaged: laps, end details, gutters and eaves, around penetrations, at interfaces with masonry, or beneath accumulated debris. Leaks may leave staining or local section loss, but a dry surface on inspection day does not establish the history or extent of deterioration. Look for distortion, perforation, packers, loose or missing fasteners, cracking, earlier patches and changes in alignment as observations to document and refer for review.

Avoid treating the most visibly corroded point as the only relevant location. A less obvious connection or support can be important to the load path, while widespread coating breakdown may warrant a different survey approach from isolated damage. The scope should explain why locations were selected and what remains outside it.

Use roof-strip access windows deliberately

Coordinate inspection milestones with the roofing contractor, facilities representative, access provider and engineer. Plan access before removal where a baseline view is useful, while sheets are off for close examination, and before insulation, new coverings or services conceal the steel again. Agree how each member and finding will be identified in photographs and on marked-up drawings.

Access is a project constraint, not a reason to infer unseen condition. Work at height, fragile surfaces, weather exposure, temporary edge protection, isolation and exclusion zones need to be managed through the project’s safety arrangements by the responsible parties. Schedule enough time for safe positioning, surface preparation where agreed, examination and recording; rushed access can make evidence difficult to reproduce.

Some inspection locations may only be reachable from above once sheets are lifted; others may require access beneath the roof or removal of local obstructions. Record areas that were concealed, unsafe to approach, wet, coated or otherwise not examinable, and identify whether the project needs a later access window. Australia Network’s industrial roof repair planning guide describes broader roof-work sequencing; coordinate the steel inspection scope with that sequence.

Choose targeted examination methods with limits in view

Begin with systematic visual examination and a location map. It can identify visible corrosion, deformation, open joints and coating breakdown, but it cannot quantify hidden section loss or rule out concealed cracking. The next method should answer a defined question at an accessible location, taking account of steel geometry, surface condition, coatings and the likely form of damage.

Ultrasonic thickness measurement may help quantify remaining thickness at selected accessible points, but it is not an automatic survey of every member. Pitting, rough or curved surfaces, coatings, probe access, member shape and measurement technique can affect readings. A small number of spot measurements may miss localised loss between points; conversely, a reading cannot be interpreted without knowing where it was taken and what nominal thickness or section is relevant. Agree the measurement locations, preparation, reference information and reporting approach before testing.

Where cracking at a weld or connection is suspected, a suitable surface examination may be considered if the material, preparation and access allow. Weld inspection can help define a focused examination, but a method name alone does not specify coverage or acceptance criteria. NDT identifies and reports responses within its scope; it does not accept a connection, certify an engineering design or authorise a lift or return to service.

Build a repeatable baseline, not just a photo folder

Give every observation a stable reference: building, gridline, member mark, face or orientation, and a measurement position where relevant. Pair overview and close-up photographs; include a scale when appropriate, and ensure the orientation can be understood later. For thickness readings, retain the reading with the point location, units, surface condition and any limitations rather than recording a value without context.

A useful baseline separates observed facts from interpretation. Note visible corrosion and its apparent distribution, measured values, inaccessible areas, coating or scale conditions, and any uncertainty. Link each item to a drawing mark-up and report reference. If coatings or debris prevent examination, state that clearly; do not present an unexamined surface as a clear result.

Consistent references support comparison if further work or future checks are considered. They also let the engineer distinguish a local result from a member-wide assumption. Keep the original drawings and reports with amended mark-ups so later project stages can see what was examined and what was not.

Separate inspection findings from capacity decisions

The engineer responsible for the building’s structural assessment needs to interpret condition evidence alongside member sizes, material information, connections, spans, restraint, design assumptions, existing loads and the proposed refurbishment. Corrosion measurements may be one input, but a capacity or load decision cannot be reduced to a thickness result in isolation. Where records are missing or the actual framing differs from drawings, identify the gap for engineering review.

Agree who receives findings, what triggers prompt review, and whether any work should pause at a location pending direction from the responsible project authority. An inspection provider can report the extent and limitations of examination; an engineering assessment determines what the evidence means for the structure and proposed work. A roof contractor’s work sequence and temporary arrangements also require their own responsible planning.

Keep unresolved observations visible in an action register: location, evidence, reviewer, next action and close-out reference. Do not convert an indication into a structural rejection without the applicable basis, or a satisfactory local test into permission to load the roof.

Refurbishment inspection planning checklist

Use these prompts at the project meeting and adapt them to the building. Assign a person to each action and include agreed review points in the programme. The checklist is a planning aid, not an engineering assessment, roofing specification or approval to proceed.