FOOTINGS
Concrete footings are required under all
support posts. Footings must extend a minimum of 30 inches below the
final grade, have an average thickness of 8 to 12 inches and be a
minimum of 16 inches in diameter. Where the footing is to support both
a deck and a roof covering, footings shall be a minimum of 24 inches
in diameter. Larger footings may also be required for decks with large
spans between posts and/or extend more than 14 feet out from the
house. All footings must be placed on stable compacted soil. Footings
shall be independent of all concrete patios that are not protected
from frost heave.
POSTS
Post sixes of 4x4 and 4x6 are acceptable
for unsupported lengths up to 8 feet. A nominal post size of 6x6 is
necessary for unsupported lengths between 8 and 13 feet. Post spacing
will depend upon the size of beam selected and the total area of the
deck. Use the following table for TYPICAL spacing of posts. All posts
must rest on top of the footing and be secured in place. Concrete
SHOULD NOT be poured around wooden posts.
| Beam Size |
Double 2x8 |
Double 2x10 |
Double 2X12 |
| Post Spacing |
6 foot |
8 foot |
10 foot |
BEAMS
Beams comprised of multiple members
shall be fastened together with three (3) 10d galvanized nails 24
inches o/c. For multiple member beams where each member is attached to
each side of the post, blocking must be provided and attached between
each ply a maximum of 24 inches o/c. All splices shall be aligned over
post supports. Beams shall be attached to support posts with an
engineered connector, (2) ½ inch carriage bolts when side mounted or
(2) ½ inch lag bolts when supported by a notch in the post. Beams may
be cantilevered a maximum of 1 foot.
LEDGER BOARDS
Decks designed to be structurally
supported from existing construction, a ledger board the same size as
the deck floor joists must be provided. The ledger must be secured
using ½ inch carriage bolts staggered 20 inches on center. Optional
½ inch lag bolts spaced 16 inches o/c may be substituted when the
existing construction affords sufficient structural material for
attachment. Ledgers must have sufficient flashing to prevent moisture
damage to unprotected construction. Floor systems constructed with
floor trusses, I-joints or specialized construction methods may
require alternative attachment methods.
*NOTE* Decks may NOT be supported
by existing cantilevered construction. An additional post and beam
system at these areas will be required to support the imposed deck
loads.
FLOOR JOISTS
Floor joists span and spacing shall not
exceed the following table or the manufacturer's recommendations. All
joists shall be toe nailed to the beam with three (3) 8d galvanized
nails, shall be attached to the ledger with approved joist hangers
installed per the manufacturer's instructions and face nailed to the
end band with three (3) 16d galvanized nails. Floor joists shall not
be cantilevered more than 2 feet.
| Joint
Spacing |
2x6 |
2x8 |
2x10 |
2x12 |
| #2 |
#1 |
#2 |
#1 |
#2 |
#1 |
#2 |
#1 |
| 12" |
9'-3" |
9'-8" |
12'-3" |
12'-9" |
15'-7" |
16'-3" |
19'-0" |
19'-9" |
| 16" |
8'-1" |
8'-5" |
10'-7" |
11'-0" |
13'-6" |
14'-0" |
16'-6" |
17'-2" |
| 24" |
6'-7" |
6'-10" |
8'-7" |
9'-0" |
11'-0" |
11'-6" |
13'-5" |
13'-11" |
STAIRWAYS
Stair must be a minimum of 36" in
width. Stair carriages must be cut from 2x12 stock, except for uncut
stringers, 2x10 stock may be used. Riser height must be uniform within
3/8" between the largest and smallest riser in the stair. Each
riser shall be between 4 and 8-1/4 inches high. Tread depth within the
flight of stairs must be equal and must have a minimum depth of 10
inches to include the nosing. Handrails must be provided on all
flights of stairs containing more than 2 risers. Stairs that rise
greater than 30 inches above the ground or adjacent walking surfaces
must be provided with guards to prevent falling. When provided,
landings for stairs shall be a minimum of 36 inches square.
HANDRAILS
Required handrails shall be provided on
a minimum of one side and be mounted 34 to 38 inches, measured
vertically from the nosing of the treads. Handrails shall be smooth,
provide a graspable surface and be continuous for the full length of
the flight of stairs.
GUARDRAILS
Guards shall be required on all decks
higher than 30 inches above the adjacent grade or surface and as
required on all stairs. Guards shall be a minimum of 36 inches high
and have opening limitations no greater than 4 inches. Required guards
along open sides of stairs shall be a minimum of 34 inches in height
measured vertically from the nosing of the tread.
INSPECTIONS
Footing - Prior to pouring concrete.
Framing - For decks less than 30" above the ground.
Final - After completion of the deck
