MOISTURE MEASUREMENT IN MASONRY:
GUIDANCE FOR SURVEYORS.
Jeff Howell – Southbank University.
The measurement and analysis of moisture contents of masonry materials are difficult subjects which are not always clearly understood, even within the discipline of materials science. For the Chartered Surveyor or Valuer undertaking survey work the situation is usually even less clearly understood, and this has lead to unfortunate compromises being made between responsibility to the client on one hand and the mortgage lender on the other!
The RICS/ISVA Home Buyers Survey and Valuation Report Form encourages surveyors to look for dampness defects using a “moisture detection meter”. This is an unfortunate instruction as it encourages surveyors to carry and use electrical conductance type meters, rather than to use the senses of sight, touch and smell and their knowledge of building construction and materials. It also lends credence to the idea that there is such a thing as a “moisture detecting meter” which as we shall see is problematic, (L’Anson and Hoff 1988, 1990).