The short answer
When a structural engineer visits, they first discuss the history and your concerns — when cracks appeared, any past work, the survey or valuation that prompted the visit. They then carry out a visual inspection, working outside (walls, cracks, roofline, ground levels, drains, nearby trees) and inside (floors for sag or bounce, walls and ceilings, the loft, any visible beams). They measure and photograph cracks, noting width and pattern, and may fit tell-tales for monitoring if movement could be active. A focused visit usually takes one to two hours; a whole-property appraisal longer. They generally do not carry out destructive opening-up on a first visit, but may recommend trial holes if the foundations need to be seen. A written report with findings and recommendations follows within a few working days.
The visit is mostly a careful visual inspection guided by the engineer's training — reading the building for how it carries load and whether anything is moving. Here is what to expect, step by step. Durations are typical, not fixed.
What to expect
- Discussion of historyfirst few minutes
- External inspectionwalls, cracks, ground, trees
- Internal inspectionfloors, walls, loft, beams
- Crack measurementwidth, pattern, photos
- Report followswithin a few working days
Before and at arrival
The visit opens with a conversation. The engineer wants the context the building cannot tell them: when you first noticed cracks, whether they are widening, any history of subsidence or insurance claims, what building work has been done, and what triggered the inspection — your own concern, a survey, or a lender's request. Having this ready makes the visit efficient and helps the engineer focus on the right areas. They will also confirm the scope — whether they are looking at one specific defect or assessing the whole property.
- Explain the timeline of any cracking or movement.
- Mention past work and whether it had Building Control sign-off.
- Point out the specific areas that worry you.
- Have any survey or valuation that prompted the visit to hand.
The inspection itself
The engineer then works methodically through the structure, outside and in.
| Area | What they look at | Looking for |
|---|---|---|
| External walls | cracks, bulging, lean | movement, overloading |
| Ground & drains | levels, gullies, trees | subsidence causes |
| Floors | sag, slope, bounce | weak or rotten joists |
| Loft & roof | rafters, ridge, beams | spread, sag, support |
Indicative areas for guidance. A focused defect visit concentrates on the relevant element; an appraisal covers all of these.
Measuring, monitoring and access limits
Where there is cracking, the engineer measures and photographs it — width, length, direction and pattern all help diagnose the cause. If they cannot tell from a single visit whether movement is active, they may fit tell-tales (small gauges across cracks) or arrange precise level monitoring to be read over the coming months. Importantly, a first visit is usually non-destructive: the engineer assesses what is visible and accessible and does not normally open up walls or dig. Where the diagnosis genuinely needs the foundation to be seen, they will recommend trial holes as a separate, later step rather than guess.
What you get afterwards
The visit is the start, not the finish. A few working days later you normally receive a written report setting out what was inspected, the findings (is the issue structural, active or historic), the likely cause, and clear recommendations — which may be reassuringly simple, such as 'cracking is historic and stable, no action needed', or may call for monitoring, trial holes or remedial design. If remedial work is needed, the engineer can usually produce the calculations and specification for it as a separate piece. Keep the report and any calculations safe: they are the documents a future buyer's surveyor, a lender or an insurer may later ask to see.
Questions worth asking on the day
The visit is your chance to get plain-English answers while the engineer is in front of the evidence, so it is worth coming with a short list of questions. Sensible ones include: Is this structural or cosmetic? — the single most useful distinction. Does the movement look active or historic? — and if they cannot say yet, what would confirm it. What is the likely cause? — a tree, a drain, settlement, overloading. What happens if I do nothing? — to understand the real urgency rather than worst-case fear. What would the remedy involve and roughly what scale of cost? — even a broad steer helps you plan. And, if relevant, will this satisfy my lender or insurer? Engineers will usually give an honest preliminary view in person, with the caveat that the written report is the formal position. Asking these on the day means you leave the visit understanding the situation, rather than waiting days for a report you then have to decode alone. A good engineer welcomes the questions — explaining the structure plainly is part of the job.
- Structural or cosmetic? — the key distinction.
- Active or historic? — and how it can be confirmed.
- Likely cause and consequences — to gauge real urgency.
- Remedy and rough scale — plus whether it satisfies a lender or insurer.
Frequently asked questions
Will the structural engineer damage anything during the visit?
No. A first visit is normally non-destructive — the engineer inspects what is visible and accessible and measures cracks. They do not open up walls or dig foundations without discussing it first, and any trial holes are arranged as a separate step.
Do I need to be home for the visit?
It helps to be there at the start to explain the history and concerns, but the inspection itself can proceed with arranged access. Make sure the relevant areas — cracked walls, the loft, side access — are reachable on the day.
How soon will I get the findings?
The engineer may give an initial verbal impression on the day, but the formal written report usually follows within a few working days. If monitoring is needed to confirm active movement, the final conclusion can take months.
Sources & further reading
Figures on this page are typical UK ranges drawn from published sources and depend on your specific project. They are guidance, not a quotation.