7.0 Diagnostic Procedure Guidelines
When diagnosing dampness in buildings there are three key criteria that must be
considered as outlined in table 7.
Item Criteria Notes
1
2
3
Table 7
Item 1
: The Search and Measure modes should be used in conjunction to (i) map out
the extent of a moisture problem and (ii) to distinguish between surface and sub-
surface moisture. The profile of readings obtained will give insight into the potential
cause (e.g. condensation, lateral ingress or rising dampness) of a moisture-related
problem.
10
Is a wall or other building
element in a safe air-dry
condition?
Is the surface temperature
of a wall or other building
element above or below
dew point?
Is a wall surface or other
building element
contaminated with
hygroscopic salts or other
conductive materials?
Air-dry is the moisture content that is normal
and safe (from moisture-related deterioration
or decay) in buildings. When the Protimeter
MMS moisture meter modes are selected,
measured values are identified as DRY, AT
RISK or WET.
Dew point is the temperature at which a given
quantity of air becomes saturated (100 %RH)
and forms dew, or condensation. If a surface
is colder than dew point, condensation occurs.
When the Protimeter MMS Condensator mode
is selected to measure T
DIFF
(the proximity of a
surface to dew point) the instrument identifies
if there is NO CONDENSATION, an AT RISK
condition, or CONDENSATION occurring.
Artificially high moisture meter readings may
be obtained in material that (i) has been
heavily contaminated by hygroscopic salts or
(ii) in materials that are conductive by nature.
The presence (or otherwise) of nitrates and
chlorides should be established when
investigating suspected rising dampness
situations in particular.
