SECTION 3: POSTS AND POST-TO-BEAM CONNECTIONS
Posts must comply with all of the following:
1.
The post height, measured from the top of the footing to the underside of the beam, must be in accordance with Table 2.
Table 2
2. Any post supporting a beam splice must be a minimum of 6”x6”.
3. Beams must be attached to posts by the appropriate methods shown in Figure 2. Toe-nailing of beams to posts is prohibited.
4. Post caps, as shown in Figure 2, must be specifically designed for 2- or 3-ply beams and the post size used. Attachment must be in accordance with the manufacturer's instructions.
5. It is recommended that cut-ends of posts should be field-treated with a wood preservative. These preservatives can be found in the paint department of most hardware or home-center stores.
Figure 2
POST-TO-BEAM CONNECTIONS
SECTION 4: BEAMS
Beams must comply with all of the following:
1.
As shown in Figure 3, the beam-span length is measured between the centerlines of 2 adjacent posts and does not include the overhangs.
2. Beam size is determined using Table 3A or 3B. The depth of flush beams must be greater than or equal to the joist depth.
3. Beams may overhang past the center of the post up to one-fourth of the actual beam span, as shown in Figure 3.
4. Where multiple 2x members are used to assemble a beam, the plies of the beam must be fastened in accordance with Figure 4.
5. Pressure-preservative-treated glulam beams are permissible for spans longer than those shown in Table 3. However, a design and plan submission is required during the permit application process.
Figure 3
BEAM TYPES
Table 3A
MAXIMUM BEAM-SPAN LENGTH1 FOR DOUGLAS FIR/LARCH
3, HEM/FIR
3, SPRUCE/PINE/FIR (SPF)
3, WESTERN CEDAR, PONDEROSA PINE
4, AND RED PINE
4
- See PDF for table - See PDF for table
Table 3B
Figure 4
BEAM ASSEMBLY
SECTION 5: JOISTS
Joists must comply with all of the following:
1.
The joist-span length is measured between the centerline of bearing at each joist-span end and does not include the overhangs. Use Table 4 to determine the joist size based on span length and joist spacing. See section 12.4 for limits on joist spacing if the decking consists of a wood-plastic composite.
2. See Figures 5 through 7 for joist-span types.
3. Joists must bear at least 3 inches nominal onto beams, unless joist hangers are used in accordance with section 7.
4. Joists may overhang past the center of the beam up to one-fourth of the actual joist span.
5. Provide full-depth 2x blocking or bridging for 2”x10” or deeper joists at intervals not exceeding 8 feet – except the blocking can be reduced to 60% of the height if placed above a beam, for drainage purposes. Attach the blocking or bridging with (3)10d toe-nails at each end.
6. Attach a continuous rim joist as shown in Figures 5 and 7 unless blocking or bridging is provided for each joist at the beam where a joist overhang begins. Attach the rim joist to the end of each joist with (3)10d nails or (3)#10 by 3-inch wood screws.
Figure 5
JOISTS WITH DROPPED BEAM – DECK ATTACHED AT HOUSE
Figure 6
JOISTS WITH FLUSH BEAM – DECK ATTACHED AT HOUSE
Figure 7
(See section 10 for more information.)
Table 4
SECTION 6: JOIST - TO - BEAM CONNECTIONS
Joists must be attached to beams in accordance with Figure 8 and all of the following:
1.
Use Options 1 or 2 if joists bear on a dropped beam.
2. Use Option 3 if joists bear at a flush beam; see section 7 for hanger requirements.
3. Mechanical fasteners or hurricane clips must have a minimum capacity of 100 pounds in both uplift and lateral directions. Installation must be in accordance with the manufacturer's instructions.
Figure 8
JOIST-TO-BEAM CONNECTIONS
SECTION 7: JOIST HANGERS
Joist hangers must comply with all of the following:
1.
The joist-hanger depth (d, as shown in Figure 9) must be at least 60 percent of the joist depth.
2. The manufactured width of the joist hanger must accommodate the number of plies being carried.
3. Do not bend hanger flanges to accommodate field conditions.
4.
For joist hangers that are fastened to a ledger board, screws which are recommended by the manufacturer must be used. All other fasteners are permitted to be nails. The number of fasteners and the manner in which they are used must be as specified by the manufacturer.
5. Use joist hangers with inside flanges if clearances to the edge of the beam or ledger board dictate.
6. Clip-angles or brackets used to support framing members in lieu of joist hangers are prohibited.
7. Joists must not frame in from both sides of the same beam. Engineering analysis is needed if more beams are needed than are shown in Figures 5 to 7.
8.
Each joist hanger must have the minimum capacity listed in Table 5.
Figure 9
JOIST HANGERS
Table 5
JOIST HANGER DOWNLOAD