General Concrete Moisture Facts

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General Concrete Moisture Facts
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Capillary Action
Capillary action is often underestimated and can
be very serious. Moisture can come from a water
table as much as 20 feet below the ground
surface.   
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Hydraulic Pressure
The action of at least two solid surfaces that
act upon water to force it, under pressure, in a
particular direction. (artesian wells, swelling
soils, broken plumbing) very rarely the cause of
moisture in slabs.  Hydrostatic pressure only
occurs below-grade.
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Leakage
Water traveling from a higher to a lower level
due to gravity. May be due to rain, flooding,
sprinkler systems, runoff, poor landscaping, etc.
In suspended floors, usually due to broken pipes
or drains, or even roof leaks.
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Water Vapor or Vapor Emissions
These act according to the physical laws of
gasses or chemical equilibrium. Water travels
from one area to another whenever a difference of
vapor pressure exists. In a controlled climate
(HVAC), the temperature in the room is 70 to 80
F and the relative humidity is 30 to 50. 
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SALTS Moisture present in
building materials always carries soluble and
insoluble salts. The most common are sodium
chloride, calcium sulfate, calcium carbonate, and
magnesium sulfate. Additional characteristics of
some of these salts, notably sodium chloride, is
that they are hygroscopic in nature, high
humidity, they absorb moisture which they lose
during periods of low humidity
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While compressive strength has long been
considered the most important quality control
characteristic of concrete, where a floor topping
is to be installed, permeability may be of equal
importance.

• Water, whether liquid or vapor, always seeks the
  path of least resistance.

• Moisture travels twice as far horizontally as
  vertically.

• There is a significant difference between
  moisture content and moisture movement
  (emission).

• Moisture usually travels through a concrete slab
  more readily as vapor than as a liquid.

• Moisture must be present in hardened concrete for
  the continued gain of strength and other desired
  properties may continue for many years.

• Healthy new concrete is alkaline with a pH of
  12.5 or more. Once cured and dried, surface
  alkalinity through carbonation drops to normal
  range.

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For more information contact here
EP Floors Corp.
Corporate Headquarters
4 Springfield StreetFifth Floor Three Rivers, MA
01080 Phone  [phone]Toll
Free  800-808-7773 Email info_at_EPFloors.comFax 
413-283-5347 Website http//www.epfloors.com