Residential Foundation
CITY OF NEWARK, CALIFORNIA
BUILDING INSPECTION DIVISION
37101 Newark Boulevard, Newark, CA 94560-3796 • 510-578-4261 • Fax 510-578-4307 • e-mail: building.inspection@newark.org
Revised August 2013
FOOTING REINFORCEMENT
All continuous concrete foundations and footings require steel reinforcement to minimize differential
settlement. For slabs on grade with monolithically cast footings, there shall be one #4 (½” diameter)
continuous deformed steel reinforcement bar at the top and bottom of the footing. Please note that
reinforcing steel must be placed so that it is at least 1½ inches from any soil (see Figures A and B
following).
TIES BETWEEN OLD AND NEW CONCRETE
New concrete slabs cast up against existing concrete footings or other slabs shall be positively attached
to one another by installing #4 dowels at 24 inches on center. For concrete footings, two dowels shall be
installed—one near the top of the footing and the other near the bottom. The dowels shall be “glued”
into the existing concrete a minimum of 6 inches using epoxy specifically made for anchoring bolts. The
drilling, cleaning, and installation of the epoxy shall be done in conformance with the epoxy
manufacturer’s printed instructions. The epoxy is made by a number of manufacturers, including
Simpson Strong Tie, and can be obtained at most hardware stores (see Figures E and F following).
ANCHOR BOLTS
All wood sill plates shall be positively attached to concrete foundations with 1/2" diameter anchor bolts
spaced no more than six feet (6') on center for single story structures and four feet (4’) on center for two
story structures. Bolts shall extend into the concrete at least seven inches (7"). Each bolt shall have a
three inch square, 1/4" thick steel washer installed under the bolt nut. Cut washers may be used at
interior partitions which are NOT part of a braced wall line. (See Figure C following.)
POWER-DRIVEN NAILS
Power-driven nails cannot be used to secure sill plates on exterior walls or any interior wall used to resist
earthquake forces. They may be used only on interior nonstructural partitions.
If power-driven nails are used, they shall be installed per the manufacturer’s printed instructions. Such
instructions shall be approved by the International Conference of Building Officials.
RAISED WOOD FRAMED FLOORS
Continuous footings for raised wood framed floor systems shall have one #4 (½” diameter) continuous
deformed steel reinforcement bar at the top and bottom of the footing. Small interior piers need not be
reinforced. The floor girders shall extend and be attached to perimeter foundation walls using factory
made sheet metal beam hangers. All interior pier posts and footings shall be tied together using factory
sheet metal post caps and bases. Toe nailing of pier posts to girders or pier blocks is not a code
acceptable method of attachment (see Figures B and D following.)
Sheet metal
post cap
Floor joist
1/5" diameter x 10" long anchor bolt
with 3" square x 1/4" thick washer
between nut and wood sill plate
Sheet metal post base
cast into concrete
6"
Concrete slab
reinforcement
4 x 4 pressure
treated post
6"
Treated
plate
Girder
6"
Min. 12"
Concrete pier
Min. 3'-4" square when supporting 100 sf of floor
Min. 2'-8" square when supporting 80 sf of floor
Min. 2'-0" square when supporting 60 sf of floor
Min. 1'-4" square when supporting 40 sf of floor
2" sand fill over 6 mil
plastic vapor barrier
12" @ 1 story
15" @ 2 story
One #4 rebar continuous
top and bottom with #3
vertical ties at 48" o/c
Figure A
Typical Footing - Concrete Floor
Figure D
Typical Pier - Raised Wood Floor
Drilled hole w/
epoxy set rebar
6"
12"
#4 rebars at 24" o/c tieing
existing footing to new slab
1/2" dia. x 10" anchor bolt w/
3" square x 1/4" thick washer
Treated
plate
Floor joist
Slab
reinforecment
Existing footing or
slab
18"
Min. 12"
12"
6"
Girder
Sheet metal hanger
15" @ 2 story
12" @ 1 story
One #4 rebar continuous top
and bottom w/ #3 vertical ties at
48" o/c
Figure B
Typical Footing - Raised Wood Floor
New slab
Thicken slab
Figure E
Existing to New Concrete Slab Tie
Drilled hole w/
epoxy set rebar
6"
12"
#4 rebars tieing
existing footing to
new footing
#3 ties at
48" o/c
3"
¼”
3"
Existing footing
Figure C
Anchor Bolt Washer Dimensions
New footing
# 4 footing
reinforcement top
and bottom
Figure F
Existing to New Concrete Footing
F:\Shared\PUBWRKS\BLDGINSP\Bldg Insp Master Drawings\B-60 drawing