LOWER BEARING AT FOOTING LOWER BEARING AT FOOTING – FROST PROTECTED
Figure 29
STRINGER BEARING
Figure 30
Tread and riser material. Treads and risers must comply with all of the following:
1.
Tread material must be equivalent to the decking specified in section 12 and be attached in accordance with Figure 31, except wood-plastic composites must be attached in accordance with the manufacturer's instructions.
2.
Stairs constructed using the solid-stringer exception noted above must have treads constructed of 2x wood material only and be attached in accordance with Figure 30.
3.
Risers that are not open (as shown in Figure 27) must be framed with 1x lumber minimum or an manufacturer recommended wood-plastic composite.
Figure 31
STAIRWAY TREADS
Table 7
1 Assumes 300 lb concentrated load, L/288 deflection limit, No. 2 grade, and wet service conditions.
2 Incising assumed for refractory species including Douglas fir-larch, hem-fir, and spruce-pine-fir.
3 Design values based on northern species with no incising assumed.
Stair guards. Guards must be provided on all open sides of stairs consisting of more than 3 risers. Stair guards must comply with section 13 and Figure 32.
Figure 32
STAIR GUARDS
Stair handrails. A flight of stairs with more than 3 risers must have at least one handrail that complies with all of the following:
1.
The handrail must be located at least 30 inches, but no more than 38 inches above the nosing of the treads – except that a volute, turnout, starting easing, or transition fitting may depart from these dimensions. Measurement must be taken from the nosing to the top of the rail.
2.
The handrail must be attached to a stair guard or exterior wall acting as a barrier as shown in Figure 33.
3.
The handrail and connecting hardware must be decay- and corrosion-resistant.
4.
The handrail must have a smooth surface with no sharp corners and must be graspable, as shown in Figure 34. Recessed sections may be shaped from a 2”x6” or five-quarter board, as shown there.
5.
Handrails must run continuously from a point directly over the lowest riser to a point directly over the highest riser.
6.
Handrails may be interrupted by guard posts.
Figure 33
Figure 34
Spiral stairs. Stair dimensions above are for standard stairs secured in accordance with methods shown in this appendix. Spiral stairs are allowed at decks when designed in accordance with the provisions of Chapter SPS 321.04. Connection of spiral stairs to decks and the supporting load path shall be designed in accordance with accepted engineering practices and with applicable provisions of the Uniform Dwelling Code.
SECTION 15: FRAMING PLAN
A typical framing plan shows a bird's-eye or plan view of the joist and beam layout; the location of the ledger board, diagonal bracing or hold-down devices, posts, and footings; and the type, size, and spacing of the ledger board fasteners. You can use the sample typical deck framing plan shown on the next page in combination with the requirements in this document to complete your deck.
Figure 35
TYPICAL DECK FRAMING PLAN
Decking: ⍽ 2x4
⍽ 2x6 ⍽ five-quarter board ⍽ wood-plastic composite (per ASTM D 7032)
⍽ Other decking, evaluation report number:
Joists: size: ⍽ 2x6
⍽ 2x8 ⍽ 2x10 ⍽ 2x12 spacing: ⍽ 12 in. ⍽ 16 in.
⍽ 24 in.
joist span dimension: ft. -
in.
overhang: ⍽ Yes ⍽ No overhang dimension: ft. - in.
rim joist: ⍽ 2x6 ⍽ 2x8
⍽ 2x10 ⍽ 2x12
Beam(s): number of plies: ⍽ 2 ⍽ 3 size: ⍽ 2x6 ⍽ 2x8 ⍽ 2x10 ⍽ 2x12
overhang: ⍽ Yes ⍽ No overhang dimension: ft. - in.
Posts: size: ⍽ 4x4
⍽ 4x6 ⍽ 6x6 height:
ft. - in.
Footings: size: in.
⍽ square ⍽ round thickness: in.
Ledger: ledger board size: ⍽ 2x8 ⍽ 2x10 ⍽ 2x12 ⍽ Not applicable (free-standing deck)
fastener: ⍽ Through bolt ⍽ Lag screw ⍽ Wood screw
⍽ Expansion anchor ⍽ Adhesive anchor
Lateral support: ⍽ Tension-tie
⍽ Diagonal bracing, size: ⍽ 2x
(not permitted for free-standing deck)
Deck size: L= ft. - in. W=
ft. - in.
