What causes damp in buildings?
Damp always has a cause.
In older houses it is often linked to moisture moving through walls, condensation forming on cold surfaces, or rainwater entering through defects in the building fabric.
Understanding the science behind damp is the first step to diagnosing the problem and choosing the right repair.
We have a YouTube channel that delves into the physics of moisture movement in buildings. Tap the image to play our latest video episode.
How do you diagnose damp in a house?
Many damp problems are misdiagnosed because the visible symptoms can have several possible causes.
Proper diagnosis involves understanding how the building was constructed, identifying where moisture is entering, and observing how damp behaves over time.
Our short infographic is a great place to start and free to download.
How can damp experts help you?
Diagnosing damp often requires specialist knowledge of building materials, moisture behaviour, and traditional construction methods.
Expertible connects homeowners with independent experts who can review your situation during a video consultation and help you understand the likely causes of damp.
They can guide you through possible next steps and help you avoid unnecessary or inappropriate repairs. Find out more about how they can help you and your house.
Case Studies
Every damp problem is different.
These real case studies show how homeowners across the UK have used expert advice to understand the cause of damp in their homes and plan the right repairs.
Each example explains the symptoms, the diagnosis, and the how the expert was able to help with practical next steps.
Is rising damp really common in Victorian houses and do I have it?
Client: Ben; Addlestone, Surrey
Property: 1890s Semi-detached
Problem: Persistent damp symptoms including black mould, salt deposits, and delaminating plaster.
Expertible: Stephen Boniface
Outcome: “I am now fully equipped to move forward without the guesswork. I have a clear checklist to diagnose the damp cause and specific material recommendations.”
Why do damp patches appear high up on walls in older houses?
Client: Jenny; Manchester
Property: 1910 mid-Terrace
Problem: Damp patches appearing in the upper corners of rooms and occasional black mould forming near the base of walls.
Expertible: Dave Smith
Outcome: “I felt like I had a plan of action. I knew what I needed to do going forward and where my money would be best spent.”
Should you tank walls to fix damp in a Victorian terraced house?
Client: Sam; Bristol
Property: 1890s End Terrace
Problem: Multiple damp areas appearing in different rooms of a late-19th century terrace house.
Expertible: Simon Hollis
Outcome: “We felt reassured that the approach we wanted to take was the right one and that the damp wasn’t actually the huge problem it appeared to be.”
Hear from people we’ve helped with their damp problems
Many damp problems are misdiagnosed because the visible symptoms can have several possible causes.
Proper diagnosis involves understanding how the building was constructed, identifying where moisture is entering, and observing how damp behaves over time.
Our damp diagnosis guide explains how experts investigate damp and the common mistakes homeowners should avoid.
Damp – FAQs
Homeowners often have similar questions when dealing with damp problems. The answers below explain some of the most common issues and misconceptions about damp in buildings.