- Project plans
- Project activities
- Legislation and standards
- Industry context
Last edited 15 Mar 2018
Rising damp in walls - diagnosis and treatment (DG 245)
On 12 October 2007, BRE published Rising damp in walls - diagnosis and treatment (DG 245 revised edition), written by Peter Trotman.
- The rate of evaporation from the wall.
- The porosity of the wall.
- The salt content of the wall and soil.
- The groundwater height and saturation.
- Heating in the building.
Some accumulation of salts can occur in the walls of old buildings even when they do not have a damp problem, so high readings from a moisture meter alone are not conclusive. Appendix A of the 12-page digest describes how to drill samples from a wall in to test for moisture content and hygroscopicity, and the interpretation of moisture gradient profiles.
If a building has a physical damp-proof course (DPC), it is unlikely that it has failed, as most dpc materials have a long life, however, defects such as mortar droppings in a cavity wall, may make a dpc ineffective by bridging it and allowing moisture to pass up through the wall. This and other mechanisms by which an existing dpc might be bridged are discussed.
The content of the digest includes:
- Mechanism of rising damp.
- Determining the source of the dampness.
- Dry lining.
- Further reading.
- Appendix: The sampling method.
 Related articles on Designing Buildings Wiki
- BRE articles on Designing Buildings Wiki.
- Building Research Establishment.
- Damp-proof course.
- Damp proof membrane.
- Defects in brickwork.
- Dew point.
- Interstitial condensation.
- Mould growth.
- Penetrating damp.
- Psychometric chart.
- Rising damp.
- Sling psychrometer.
- Treating brickwork with sealant or water repellent.
- Understanding dampness.
 External references
- BRE Digest 245, Rising damp in walls - diagnosis and treatment.
- Good Repair Guide 33 - GRG33.
Featured articles and news
93% believe tackling the construction knowledge gap is very important or extremely important for the industry.
Book review: The vertebrate architecture of one of the most important practices of the 20th century.
Matt Rhodes, Quiss Technology, explains how an increasing number are falling victim to sophisticated cyber-attacks.
Assembly drawings represent items that consist of more than one component and show how they fit together.
Is the water sector under too much pressure from the regulator?
Everything you need to know about acoustics in under 800 words.
Check out our list of the 90 most unusual buildings of all time.
The government is to set a personal consumption target to reduce water use.
BSRIA calls for more education to promote fuels that are fit to burn.
Michael Gove admits air pollution is making people ill and shortening lives.
BRE call for a clearer, focused drive for the delivery of sustainable, quality developments.