Moisture Inspection

This presentation was created with the kind support of the FRVŠ grant 2969/2011

Contents

� Moisture transport through materials� Moisture measurement

Moisture transport throughbuilding material

DifussionCapillary elevationHygroscopySurface condensationAtmospheric water

Diffusion

moisture move from a centre of high concentrationto low to achieve an equilibrium concentration

CapillaryCapillary attractionattraction

relatedrelated to to thethe surfacesurface tensiontension ofof waterwater

CapillaryCapillary attractionattraction

In In practicepractice::

•• mmateriaterialsals withwith biggerbigger poros poros absorbabsorb waterwater quicklyquickly, , butbutthethe highhigh isis lowlow

•• smallsmall pporousorous materimaterialsals absorbabsorb waterwater slowlyslowly, , butbut veryveryhighhigh

•• meanmean diameterdiameter ofof porousporous in in masonrymasonry 1010--5m,5m,itit correspondscorresponds toto highhigh ofof capillarycapillary actionaction1,49m1,49m

Surface condensationthermalthermal bridgesbridges ((surfacesurface moisturemoisture isis higherhigher thenthen interstitialinterstitial))

Hygroscopicity

hygroscopichygroscopic saltssalts (e.g.(e.g.calciumcalciumchloride)chloride) trytry to to achieveachieve equilibriumequilibriumwithwith theirtheir surroundingssurroundings by by takingtakingupup oror releasingreleasing moisturemoisture

Gravity-hydrostatic pressure

in in basementbasement wherewhere thethe waterwater table table isis wellwell aboveabovebasementbasement floorfloor levellevel

Key moisture sources

AtmosphericAtmospheric waterwaterWindWind presurepresure rainrain waterwater

forcingforcing thethe moisturemoisture to to enterenter thethe materialmaterial

Poor details on horizontal parts

Poor details on horizontal parts

Rainwater goods leak

Blocked rainwater goods

Moisture Measurement

MoistureMoisture analyseranalyserFullyFully automaticautomatic, , dryingdrying untiluntil constantconstant weightweight

Maximum Maximum weightweight capacitycapacity 45g45g

MoistureMoisture analysisanalysisgravimetricgravimetric methodmethod –– laboratorylaboratory testingtesting

MoistureMoisture analysisanalysis

Um = (mUm = (m--mmss) / ) / mmss 100 100 [[%%]]

-- accurateaccurate methodmethod

-- determinationdetermination ofof moisturemoisture gradientsgradients fromfrom withinwithin

thethe thicknessthickness ofof a a materialmaterial