FACT:
"As new concrete dries, it shrinks, or shortens in all directions.
The amount of shrinkage depends on many factors, but most concretes
shrink about 1/8 inch in 20 ft." (Source: Concrete Craftsman
Series, CAST-IN-PLACE WALLS, published by the American Concrete
Institute.)
Remaining
in the absence of this concrete shrinkage are multiple shrinkages cracks
(mostly hairline) which collectively compensate for the 1/8 inch loss in
20 feet of wall. Expect most shrinkage to occur within the first 28
days. However, it is not uncommon for new shrinkage cracks to appear 2
to 3 years after the wall cast!
It
wasn't easy! First, we installed a full width / full height weakened plane
joint inside the wall forms. Also, reinforcing rods were tied vertically
in place. Then, a steel cable sling was wrapped around the rods. A loop
end of steel cable was positioned so that we could hook onto it later
after the forms were stripped. Lastly, we made sure the end of the wall we
wanted to side was not anchored to the footing. Cardboard was placed on
top of the footing so there would be no bond between it and the wall. It
worked.
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