Far greater insight will be obtained from moisture readings taken in a methodical
manner to those taken in a random manner. When testing walls, the user is
recommended to commence by taking readings at the skirting board level and move
up the wall in regular steps of 10-15 cm. When high sub-surface relative readings are
obtained in the Search mode, the user is strongly recommended to quantify these
values in %WME terms by using the Deep Wall Probes in the Measure mode. If the
depth of clearance holes is increased incrementally by a nominal 1cm at a time, the
moisture profile through the wall can be established.
Item 2:
Condensation related moisture problems are arguably the most prevalent.
When assessing the risk of condensation, or confirming its existence, the proximity of
the actual temperature of the surface under investigation to the dew point must be
established. The
TDIFF
measurement in CONDENSATOR mode tells the user how many
degrees the temperature of a surface is above or below the dew point.
As many condensation situations are transient, T
DIFF
readings should be taken in a
methodical and regular manner, similar to moisture meter readings in materials.
Ambient RH and temperature values should also be taken to assess the moisture
condition of the room as a whole. Dwellings and working environments generally have
an RH of between 40% to 60%, so there may be cause to investigate environments that
register RH values outside this range.
Item 3:
Two hygroscopic salts, chlorides and nitrates, may build up on the surface of
walls where rising dampness occurs. As groundwater moves through the wall and
migrates to the surface, salts tend to accumulate where the rate of evaporation of this
water is greatest. The salts themselves are non-conductive, but when mixed with a small
amount of moisture a highly conductive solution is formed. The presence (or absence)
of such salts should therefore be established when rising dampness is suspected by
using the Protimeter MMS in Measure mode as described. When required, the
Protimeter Salts Analysis Kit (part number BLD4900) can be used to identify the relative
concentrations of nitrates and chlorides.
In summary, effective dampness diagnosis is a process that draws on the knowledge
and expertise of the surveyor. The Protimeter MMS kit enables the practitioner to
investigate moisture levels in materials and environments from various perspectives
that, in turn, enables him/her to make more thorough and reliable judgements as to
the cause of dampness related problems.
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