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Waterproofing Essentials:Moisture Signs And Symptoms
Today we will go on with moisture diagnosis and will cite the most common moisture symptoms and signs.
By identifying / locating symptoms and signs of moisture you specify the problem which is the first step in a moisture audit.
Deliberately, we won't distinguish among different parts of the building envelope - e.g. walls, roofs, basements - since this won't serve any of the objectives of this entry.
MOST COMMON MOISTURE SIGNS AND SYMPTOMS
MOLD / MILDEW
Though the above terms carry a slightly different connotation, they can be used interchangeably. Both refer to fungal growth.
Mold existence betrays moisture existence, so search for a moisture source.
Most times moisture is due to condensation (please check out the relevant entries).
MUSTY ODORS
High internal relative humidity is the main prerequisite for musty odors which can exist without the physical presence of mold.
Musty odors are the heralds of mold.
SURFACE CONDENSATION / CONDENSATES
Very common, especially during the heating season. You can see fogged windows, sweating pipes and walls etc. A result of high indoor relative and absolute humidity, surface condensation is visible and takes place on the surface of non-porous materials whose temperature is below dew point.
Please check "THE 4 PILLARS OF CONDENSATION PREVENTION".
INTERSTITIAL CONDENSATION
Conversely this type of condensation is hidden / not visible and mostly takes place when internal warm air diffuses into porous walls. Much more difficult to diagnose, it usually needs invasive testing.
DAMP FEELING
A sense of dampness you feel in areas with elevated humidity levels.
WOOD ROT AND DECAY
This shows serious moisture intrusion and damage. Wood fungi make wood soft, spongy and weak. Moisture will increase possibilities for pest infestation.
DEFORMATIONS
Moisture can cause volumetric changes, warping, swelling, shrinkage, twisting etc.
SPALLING / CRUMBLING / CHIPPING
These phenomena may be due to cryptoflorescence which is concentration of salts behind the surface of building materials. It is a type of efflorescence which takes place when special conditions prevail.
Freeze-thaw cycles act synergistically to speed up deterioration process. Masonry can turn to be powdery or crusty.
EFFLORESCENCE
Could be primary (happens during the initial cure of mortars or concretes) or secondary. It's a salty deposit on the surface of porous building materials. Sometimes it's hard and crystalline, other times powdery. It can turn to fluffy under the action of certain fungi.
PEELING PAINT / DELAMINATIONS / FLAKING
Culprit could be diffusion process. Vapors condense near the external surface and cause paint peeling, stucco flaking etc.
Capillary absorption or rising damp is another common cause.
BLISTERING
Moisture is trapped behind waterproofing membranes and causes local detachments due to high pressures.
DRYWALL SOFTNESS
Chemical deterioration and dissolution of gypsum products.
MILKY STAINS
Hydrolysis and leaching of certain polymer dispersions used for cement mixes waterproofing and modification.
WET STAINS / DISCOLORATION
Can originate from water ingress or leaking and subsequent pervasion. Also from capillary absorption or condensation.
STANDING WATER
Standing water is usually found in basements due to bulk water ingress. This situation calls for immediate waterproofing.
Could also occur due to serious condensation or above ground moisture intrusion.
Moisture symptoms can be detected by:
- Visual inspection: Assessment or existing conditions.
- Non invasive testing: Will corroborate the conclusions from the visual inspection.
- Invasive testing: This will necessitate destructive methods e.g. removal of materials etc.
Chris Strogilis
Civ. Eng. - MBA - DipM
http://maconwaterproofing.blogspot.com/
About the Author
Civil engineer with postgraduate studies in MBA and Marketing