Rising damp – does it exist?
In a recent case review Stephen Cornish MA BSc FRICS FFPWS challenged the conventional reporting style of surveyors and asked the question “Does rising damp actually exist?”.
In a recent case review Stephen Cornish MA BSc FRICS FFPWS challenged the conventional reporting style of surveyors and asked the question “Does rising damp actually exist?”. Stephen, the Managing Director of Woodward Chartered Surveyors, reported that sometimes what is described as rising damp in home buyer reports, with subsequent recommendations for injection of a chemical damp proof course, may not actually be so.
The capillary action (the means by which rising damp moves up in a wall) is often quoted as being up to a meter above ground level. But demonstrations challenge this and show that in brick work, it is no more than a few centimetres.
Quoting from a series of studies and particularly the authoritative work of Malcolm Hollis, Stephen explained that a building is always in a dynamic state of change, affected by changing water levels in the ground and therefore water pressure on the building, changing levels of moisture in the air, air temperature and how the building is used or altered in its construction.
Stephen highlighted research from his Master’s Degree, surveying medieval buildings in London, and found no rot at all to basement timbers of 500 years ago. Where was the rising damp there?
Stephen believes that a good surveyor needs to take a broad review when considering why dampness is in the wall and not simply report it is there, leaving the home buyer to mistakenly instruct a builder to inject a chemical damp proof course (dpc), which may fail to eradicate the problem or simply move the dampness somewhere else, often to a higher level. In a Building Survey, the surveyor should identify the symptom, locate the failure and recommend a solution (subject of course to the restrictions of the survey – you can not often knock holes in a wall you do not yet own!).
For more information on choosing the right type of survey, Stephen has prepared a series of short helpful videos at http://www.woodwardsurveyors.co.uk/videos.