What a useful survey should tell you.
A damp survey should explain the likely source, the evidence supporting it, other possible causes, repair priorities and which areas need attention.
The scope varies between an initial homeowner survey, which may be free where the property and purpose are eligible, and a paid written report for a buyer, landlord or legal file. Ask which kind you are booking and what document you will receive.
History and timing
When did it begin? Does it follow rainfall, winter, occupancy or building work? What has already been tried?
Internal pattern
Survey the affected surface and surrounding areas, finishes, salts, timber and the height and shape of readings.
Humidity and airflow
Consider indoor humidity, cold surfaces, extraction, background ventilation and the routes air takes through the home.
External inspection
Review rainwater goods, roof junctions where visible, pointing, render, openings, ground levels, drainage and obvious defects.
Other possible causes
Compare the signs of leaks, condensation, penetration, bridging and low-level moisture using several consistent clues.
Practical report
Explain priorities, limitations, recommended trades or treatment, making-good and any monitoring needed.
Prepare useful evidence.
Send the full postcode, explain which rooms or outside areas are affected, and note when the problem changes. Gather photographs, previous reports, repair invoices and details of recent roof, window, plumbing, insulation or plaster work.
Make the affected areas accessible where possible. Tell the surveyor about tenants, shared roofs or walls, locked rooms, pets, suspected hazards and any area that cannot be inspected. Do not put yourself at risk to reach a roof space, electrical fitting or unsafe structure.
What can be seen
A survey normally covers accessible rooms and visible outside areas. Restricted, concealed or shared parts may need permission, opening-up or another specialist.
What readings mean
Readings are useful when tied to the wall, material, pattern and conditions. They do not identify a cause on their own or predict how a building will dry.
What it cannot promise
A routine damp survey is not a structural design, medical opinion, legal determination or guarantee that a proposed repair will solve every future symptom.
Check that the report says what was found.
For a written report, look for the property and inspection date, areas and methods covered, relevant observations and readings, the reasoning behind the likely cause, alternative causes considered, limitations, repair priorities and any recommended follow-up.
It should also make clear what was not inspected, which work belongs to another trade, whether monitoring is needed and whether the advice is a quotation, specification or general survey report. Keep the document with photographs and later repair records.
Before you accept a specification.
- What evidence supports this diagnosis?
- Which alternative causes were checked?
- Does the outside defect need repairing first?
- What happens to contaminated or damaged finishes?
- What maintenance, access or guarantees apply?
- What would make the diagnosis change?