Record the crack before deciding what caused it
Note where the crack begins and ends, its direction and whether it passes through plaster, brickwork or both. Look at the same part of the building outside. Diagonal or stepped cracking around doors and windows deserves attention, but shape alone cannot establish subsidence. Fine cracks at plasterboard joints are common and may be decorative.
Ask when it appeared and whether it has changed. A dated photograph from the seller can be helpful. Fresh filler or paint is not proof that something has been hidden; people decorate before selling. It does mean the surveyor may have less visible evidence, so show them exactly what you noticed.
Look for related movement rather than one isolated line
Try doors and windows. Note sticking frames, gaps that taper, sloping floors or skirting that has separated from the wall. Outside, look for cracking through bricks, distorted openings and movement where an extension meets the original house. Several connected signs carry more weight than one hairline crack in new plaster.
Trees, drains, foundations, alterations and ground conditions may all be relevant, but do not choose a cause from a checklist. Your surveyor may recommend monitoring, drainage checks or a structural engineer. Ask what evidence prompted that advice and whether it needs resolving before exchange.
Damp at low level is not automatically rising damp
Blistered paint, damaged skirting and salt marks near the floor may occur with rising damp. They can also follow a plumbing leak, high outside ground, a bridged cavity, defective rainwater goods or moisture trapped after earlier work. Look outside the affected wall and ask what lies beneath the floor.
Dark surface mould in a cold corner behind furniture points more towards condensation than moisture rising through masonry. A hand-held meter can show that a material conducts electricity; it does not identify the source. Diagnosis should use the building’s construction, the moisture pattern and nearby defects, not one reading in isolation.
Ceiling and chimney stains need context
A brown mark below a bathroom may come from a failed seal, pipe joint or earlier overflow. Staining near a chimney can involve flashings, porous masonry, condensation in an unused flue or old contamination. Ask whether the mark changes after rain or when plumbing is used.
Look for softness, flaking and a clear repair edge. If the surface is dry, find out when it last appeared and what was repaired. A decoration invoice proves only that decorating occurred. Where the source remains uncertain, the surveyor may suggest a roofer, plumber or damp specialist who can inspect the relevant area.
Smell and ventilation can add useful evidence
A persistent musty smell is worth following, especially in cellars, fitted cupboards and rooms above suspended timber floors. Check air bricks outside and look for furniture tight against cold walls. Windows left wide open during a cold viewing may simply be airing the home, but ask about condensation and heating habits.
Do not lift carpets or remove panels without permission. A surveyor can inspect accessible areas and explain when a more intrusive check would be justified. If there is concern about hidden timber decay, agree with the seller what access can be provided before assuming the whole floor must be replaced.
Get the scope of further advice clear
If the survey recommends another report, ask what question it should answer. “Obtain a damp report” is too broad unless the affected walls, likely sources and required evidence are identified. Choose a specialist with suitable experience and be cautious where a free inspection leads directly to one predetermined treatment.
For movement, ask whether the surveyor saw active signs, historic movement or only a feature that could not be explained during a limited inspection. The lender and insurer may need information too. Keep the reports consistent and disclose what is asked. Your decision should reflect the likely work, the remaining uncertainty and whether the purchase still suits your appetite for repairs.
When photographs are allowed, include a wider view as well as a close-up. The position beside a window, drain, chimney or extension joint often tells the surveyor more than a tightly cropped picture.