Damp in a property: what might a survey tell you?

Understand why damp is a symptom, not a single diagnosis, and what follow-up may be needed. 

Damp is a common concern for homebuyers, but visible staining or a high moisture reading does not by itself explain the cause. A surveyor considers the location, pattern, building construction and other visible evidence. 

Common moisture sources 

Potential causes include condensation, plumbing leaks, defective roofs or gutters, penetrating rainwater, high ground levels, damaged finishes or moisture moving through the building fabric. 

Why the building type matters 

A repair that suits one property may be inappropriate for another. Older buildings can rely on permeable materials and ventilation to manage moisture, while modern construction may use different barriers and cavities. 

What the surveyor can do 

The surveyor can report visible signs, take readings where appropriate, consider likely causes and recommend repairs or further investigation. The inspection does not normally involve opening up walls or floors. 

When specialist advice may be needed 

If the cause or extent cannot be established visually, the report may recommend a suitably qualified damp, timber, roofing, plumbing or building specialist. Seek independent advice and avoid committing to treatment before the cause is properly considered. 

Questions to ask 

Where is the moisture coming from? Is it active? What building defect may be contributing? What repair is recommended? Is further investigation needed before exchange? 

Use evidence in your decision 

If significant work is likely, obtain quotations and discuss the implications with your conveyancer and the seller before you commit.