 |
| |
|
FASTFOOTฎ
by |
 |
|
RISING DAMP - Potential for Rising Damp |
|
<back to menu
POTENTIAL OF RISING DAMP: TEST TO MEASURE
OCCURRENCE
|
(September 18,
2003) Fab-Form Industries conducted a simple test to measure
the quantity of water wicked up through a concrete column.
The test was carried out under the supervision of Phoenix
Engineering Ltd., a leading Geotechnical Engineering Firm
specializing in the movement of water in soil structures.
Testing Apparatus
A column of concrete 5-1/2" in diameter and 28" in height
was set on end in a 5 gallon plastic bucket filled with
7-1/2" of water (about 10-1/2" after installing the
concrete). To prevent the evaporation of water from the
bucket itself, the top of the bucket around the column was
sealed with a sheet of polyethylene plastic.
|
|
Overview of Testing
Apparatus
Click for larger image.
September 5th, 2003 - The
polyethylene membrane is placed over the bucket to prevent
evaporation from the bucket itself. Notice the darkened area
on the column where the concrete is extremely damp due to
the wicking action of the concrete. Also notice the salts
left behind from the evaporated water.
|
After allowing five days for
the water to wick up the column, the bucket was weighed each
morning for 2 weeks to measure the quantity of water wicked
up through the concrete and evaporated into the air above.
The test took place in early September - air conditions were
warm and dry. The bucket was set on a desk, exposed to
reasonable ventilation with no direct sunlight.
|
|
The Test Bucket with PE
Removed
Click for larger image.
September 8th, 2003 - Here is
the bucket with the polyethylene cover removed, at the end
of the test. Notice how there are no salts below the PE
cover height, as no evaporation took place below the cover. |
| |
|
|
|
|
Results
As can be seen from the graph, the weight on
the first day of measurement, August 26th, was 77.6 lbs.
Thirteen days later, September 8th, the weight had dropped
to 70.6 lbs., a total loss of 7.0 pounds, which equals
7.0/13, or .54 pounds per day of wicking and evaporation.
The cross sectional area of the 5-1/2" column was .16 square
feet. Therefore one square foot of concrete wicks up .54/.16
or 3.38 pounds of water per day. |
| |
|
|
How
Much Water Can a Foundation Wick?
A typical basement has approximately 200 lineal feet
of wall, 8" thick, hence a cross sectional area of 133
square feet (200' x 8"/12"). The foundation concrete has the
capacity to wick at least 435 pounds of water each day (3.38
x 133) under similar conditions to the test. As 435 pounds
of water is equivalent to ten 5-gallon buckets of water each
day, it is evident that
rising damp can be a
major contributor to moisture and mold in basement
foundations.
Would a typical basement wick this quantity of water? Only
if there was water ponding surrounding the footing (which
occurs with impervious soils not correctly drained), and
where the interior walls were openly exposed to dry interior
air. In most basements, the quantity of water wicked through
the foundation would be considerably less. Mold growth,
however, requires a slow and persistent moisture source,
which is exactly what rising damp is good at providing.
Conclusions
Rising damp can be a major contributor to dampness and molds
in basements.
ALL concrete in contact with moisture laden soils must be
protected from moisture by a membrane (or other appropriate
method).
Maximum moisture levels surrounding a basement are typically
found at the bottom of the excavation where the concrete
footing is located.
Concrete footings must be protected from ground moisture.
The Fastfootฎ membrane is a
cost effective method of preventing rising damp in
concrete footings.
For a printable report on rising damp,
please
click here.
 |
|
|
 |
 |
|
Products |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
|
|
|
|
| |
| Related Links: |
|
|
|
