Installation Instructions

FAD can
accommodate
various footing
depths. Proceed
as current practice
or code in your
area dictates for
wood or metal
forms. Following
are suggestions for
installation . For
maximum drainage,
FAD should be
installed on both
sides of the footing.
WALLINTERIOR EXTERIOR
FLOOR
SLAB
FOOTING
CONCRETE FILL BELOW FORM-A-DRAIN
UNDISTURBED
EARTH
INTERIOR EXTERIOR
FLOOR SLAB
WALL
FOOTING
FORM-A-DRAIN
WALLINTERIOR EXTERIOR
FLOOR SLAB
FOOTING
FORM-A-DRAIN
UNDISTURBED
EARTH
Raised/Elevated-FAD: Low-Slump-Concrete
Depending on the footing depth required, raise the top of the lineal
to meet the top elevation of the footing. For example, if 8" lineals
are being used to form a 10" footing, there would have to be 2" of
space between the bottom of the lineal and the excavated ground
(which would be filled in with gravel or concrete). Likewise, 6"
lineals may be used to form 8" footings, or 4" lineals may be
used to form 6" or 8" footings.
Combination FAD with Earth or Trench Forming
This method involves using both lineals and undisturbed earth to
form the required footing depth. For example, 4" lineals may be
used to form an 8" footing in combination with a trench excavated
4" below the bottom of the lineal; there would be a total of 8" of
concrete — 4" formed by the lineal plus 4" formed by the earth.
Similarly, a 10" footing could be formed by combining a 6" lineal
and 4" trench; a 12" footing by combining a 6" lineal and 6" trench
or an 8" lineal and 4" trench.
Perimeter Excavation Only: Higher Slump Concrete
Some contractors prefer this method to save on excavation and
gravel cost. A wide (typically 3' to 4') area around the perimeter of
the floor plan is dug 4" to 6" deeper than the center. Undisturbed
earth remains in the center of the excavation. The lineals are then
installed such that 4" of the footing height is above the undisturbed
earth, and 2" to 4" is below. The trench is then filled with gravel,
and a 4" layer of gravel is spread over the undisturbed earth to
serve as the sub-base for the basement slab.
TWO-SIDED FORMING
ONE-
SIDED
FORMING
Either the inside
or outside FAD
lineal may be
replaced by a
form for one-sided
drainage. Form
can be wood,
metal, plastic,
composite, etc.
STONE
Place stone in the same manner as current practice. In some
cases, putting stone in place prior to the concrete pour can hold
the Form-A-Drain system in place.
Where required, separate filter
fabric must be installed. Partially
backfill outside of footing with
appropriate stone, apply
geotextile or filter fabric as
illustrated (right) and complete
backfilling with stone.
ALTERNATIVE FORM METHODS
WALLINTERIOR EXTERIOR
FLOOR
SLAB
FOOTING
F
ORM-A-DRAIN SURROUNDED BY GRAVEL
5