Diagnosing the causes of dampness (GR 5 revised)
BRE (Building Research Establishment) is an independent, research-based consultancy, testing and training organisation, operating in the built environment and associated industries.
Diagnosing the causes of dampness (GR 5 revised) was written by John Houston and published by BRE on 18 March 2015.
Even in a ‘dry’ building, there is a surprising amount of water in porous materials, most of which does no harm. A building is only considered to be 'damp' if the moisture or its effects become visible, leading to deterioration in decorations or the fabric of the building.
Dampness is the most common problem in housing. It results in visible wetting of walls, ceilings and floors, blistering paint, bulging plaster, sulfate attack on brickwork and mould growth on surfaces and fabrics, usually accompanied by a musty smell. It can also lead to less obvious problems such as a reduction in the effectiveness of thermal insulation or cracks in brickwork due to the corrosion of embedded metal components.
The first step in solving damp-related problem is to diagnose the cause.
This Good Repair Guide provides advice on how to identify the potential causes of dampness in homes. It is aimed at housing professionals, home owners and occupiers, and replaces guidance published in 1997.
Its contents are:
- Introduction.
- Internal dampness: moisture from condensation.
- External dampness: rain penetration.
- External dampness: rising damp.
- Construction moisture.
- Leaking pipes.
- Leaking roofs.
- Spillage.
- Ground and surface water.
- Contaminating salts.
- Hidden dampness.
- Specialist inspection.
- References.
Other guides in the series, Good Repair Guides 6–8, cover specific remedial treatment for the principal causes of dampness.
[edit] Related articles on Designing Buildings Wiki
- Assessing moisture in porous building materials.
- BRE articles on Designing Buildings Wiki.
- BRE Buzz articles on Designing Buildings Wiki.
- BRE Buzz.
- BREEAM.
- Building damp-free cavity walls.
- Building Research Establishment.
- Condensation.
- Damp in buildings.
- Damp proof membrane.
- Damp proofing.
- Damp-proof course.
- Dew point.
- Dry rot fungus.
- Efflorescence.
- Humidity.
- Interstitial condensation.
- Penetrating damp.
- Rising damp in walls - diagnosis and treatment (DG 245).
- Rising damp.
- Spalling.
- Understanding dampness.
- Wall insulation and moisture risk.
Featured articles and news
Apprenticeships and the responsibility we share
Perspectives from the CIOB President as National Apprentice Week comes to a close.
The first line of defence against rain, wind and snow.
Building Safety recap January, 2026
What we missed at the end of last year, and at the start of this...
National Apprenticeship Week 2026, 9-15 Feb
Shining a light on the positive impacts for businesses, their apprentices and the wider economy alike.
Applications and benefits of acoustic flooring
From commercial to retail.
From solid to sprung and ribbed to raised.
Strengthening industry collaboration in Hong Kong
Hong Kong Institute of Construction and The Chartered Institute of Building sign Memorandum of Understanding.
A detailed description from the experts at Cornish Lime.
IHBC planning for growth with corporate plan development
Grow with the Institute by volunteering and CP25 consultation.
Connecting ambition and action for designers and specifiers.
Electrical skills gap deepens as apprenticeship starts fall despite surging demand says ECA.
Built environment bodies deepen joint action on EDI
B.E.Inclusive initiative agree next phase of joint equity, diversity and inclusion (EDI) action plan.
Recognising culture as key to sustainable economic growth
Creative UK Provocation paper: Culture as Growth Infrastructure.
Futurebuild and UK Construction Week London Unite
Creating the UK’s Built Environment Super Event and over 25 other key partnerships.
Welsh and Scottish 2026 elections
Manifestos for the built environment for upcoming same May day elections.
Advancing BIM education with a competency framework
“We don’t need people who can just draw in 3D. We need people who can think in data.”