All framing per 2018 IRC Section R507 and the Franklin County Deck Guide. Design live load 40 psf + dead load 10 psf.
Overall Framing Layout#
- Deck footprint: 14’-0" deep (N–S, out from house) × 13’-10" wide (E–W, along house), with the two outer corners (opposite the house) clipped diagonally — cut length = 23" (hypotenuse), legs = ~16.3".
- Joists run perpendicular to the house. Ledger on the house wall, single beam near the outer edge.
- Joist back-span (ledger to beam) = 11’-9". Joist cantilever past beam to outer edge = 2’-3". Total deck depth = 14’-0".
- Beam runs parallel to the house, length = 13’-10" (matches deck width), supported by (3) 6×6 posts.
- Deck surface slope: ⅛" per foot (~1%) away from the house — ~1¾" total drop across the 14’-0" depth. Not code-required (IRC R507 does not mandate deck surface slope for PT gapped-board decks), but added as best practice for moisture management. Achieved by setting the top of the beam 1½" below the top of the ledger (matches ⅛" × 11’-9" back-span = 1.47"); joists then carry the same slope through the 2’-3" cantilever so the outer rim sits ~1¾" below the ledger top.
Footings#
| Parameter | Value |
|---|---|
| Footing type | Concrete pier, bearing on undisturbed soil |
| Minimum depth below grade | 32 in. (frost depth for Franklin County) |
| Footing diameter | 18" dia. (sized for tributary area ≈ 48 sq ft per post at 1,500 psf presumptive bearing — FCDG Sheet 2, Table R507.3.1) |
| Footing thickness | 8 in. min. |
| Concrete strength | 3,000 psi minimum at 28 days |
| Reinforcement | Per Franklin County Deck Guide (unreinforced pier is acceptable at this scale; owner may include (4) #4 vertical bars for robustness, optional) |
Posts#
| Parameter | Value |
|---|---|
| Post size | 6×6 Southern Pine #2, PT, ground-contact rated (UC4A min.) |
| Post count | (3) along the beam line |
| Post spacing | ~6’-11" o.c. (13’-10" beam length ÷ 2 spaces) |
| Post-to-footing connector | Simpson ABU66Z standoff post base |
| Post-to-beam connector | Simpson AC6Z or PCZ post cap |
| Max post height | 14 ft per FCDG Sheet 5, Table R507.4 — tallest post on this deck well under limit |
Post / Footing Layout (plan dimensions)#
| Post | Offset east from west deck edge | Offset north from house wall (beam latitude) |
|---|---|---|
| P1 (west) | 0" (centerline at west rim) | 11’-9" |
| P2 (middle) | 6’-11" (83") | 11’-9" |
| P3 (east) | 13’-10" (166"; centerline at east rim) | 11’-9" |
End post centerlines are on the rim line; in construction they may be inset ~3" inboard of the outer face of the rim joist so the full 6×6 section sits below the deck — builder discretion, does not affect the dimensions above.
Existing buried 4×4 posts at the approximate 12’-0" latitude are not code-compliant footings (post-in-ground method, not permitted under RCO R507). They are being removed entirely during demolition — see Scope of Work, Step 1. The new beam line sits ~3" inboard (south) of the old post row, so each new pier hole may pass through part of an old post’s disturbed zone; this is acceptable because each new pier is augered fully to 32" below finished grade and the bearing surface at the bottom of the hole is undisturbed native soil below any old disturbed backfill.
Beams#
| Parameter | Value |
|---|---|
| Beam species/grade | Southern Pine #2, PT |
| Ply count | 2-ply |
| Nominal size | 2×8 |
| Beam length | 13’-10" |
| Max beam span between posts | 8’-9" (FCDG Sheet 3, Table R507.5, 2-ply 2×8 SP at ~7’ tributary) — we specify 6’-11", safe |
| Ply-to-ply connection | (2) rows of Simpson SDWS22500DB structural screws (or 10d nails) at 16" o.c., staggered |
| Splicing | No splices permitted between posts; if a splice is required, center over a post |
Joists#
| Parameter | Value |
|---|---|
| Joist size | 2×8 Southern Pine #2, PT |
| Spacing | 16" o.c. |
| Maximum span (allowable) | 11’-10" per FCDG Sheet 3, Table R507.6 (SP 2×8 at 16" o.c., 40 psf LL + 10 psf DL) |
| Actual back-span | 11’-9" — ledger to beam |
| Maximum cantilever (allowable) | 2’-3" per FCDG Sheet 3, Table R507.6 (also ≤ ¼ back-span per R507.6) |
| Actual cantilever | 2’-3" — beam to outer edge |
| Joist-to-ledger | Simpson LUS28 face-mount hanger |
| Joist-to-beam | Joists bear fully on top of beam (primary vertical load path); Simpson H2.5A hurricane tie at each joist for uplift resistance only (not primary bearing) |
Note: The 2×8 joist depth is dictated by the 2×8 ledger — a face-mounted joist cannot be deeper than the ledger it hangs from.
Ledger Attachment#
Per IRC R507.9. Positive mechanical connection to the house floor framing.
| Parameter | Value |
|---|---|
| Ledger size | 2×8 PT SP #2, ground-contact rated |
| Fastener | ½" dia. hot-dipped galvanized through-bolt with washers (preferred); ½" lag screw where through-bolt access from the interior is not practical |
| Fastener spacing | 23" o.c. staggered for ½" through-bolts (or 15" o.c. staggered for ½" lag screws) per RCO Table 507.9.1.3(1) — 2×8 SP joist, 11’-9" back-span, 40 psf LL + 10 psf DL. Edge/end distances per RCO Figures 507.9.1.3(1) and 507.9.1.3(2). |
| Attachment substrate | Solid sawn lumber house band joist (also called the rim joist) — 2× lumber. Installation into rim board (OSB/LVL-composite rim) or sheathing alone is not permitted. Owner to verify band-joist type and condition before ledger install; replace rot-compromised lumber prior to ledger attachment. |
| Lateral load connection | (2) Simpson DTT2Z tension ties per RCO 507.9.2, located at approximately the ¼-points along the ledger, connecting the deck joists through the band joist to interior floor framing (positive connection to house floor framing, not to sheathing alone). Detail per Franklin County Deck Guide. |
| Flashing | Corrosion-resistant metal drip cap / Z-flashing continuous over the top of the ledger; step flashing where ledger meets wall cladding; integrate with existing WRB |
Guardrail / Handrail#
Per IRC R312 and R311.7.8.
| Parameter | Value |
|---|---|
| Guardrail required | Yes — deck measures 28" to ~30" above grade depending on measurement point; design provides guardrail to satisfy IRC R312 at the worst-case 30" condition |
| Guardrail height | 36 in. minimum from deck surface to top rail |
| Balusters | 4 in. sphere cannot pass |
| Guardrail post attachment | Guardrail posts mounted inside the rim joist with full-height solid blocking between joists; secured with Simpson DTT2Z hold-down tension tie per IRC R507.10. Posts are not notched. |
| Handrail height (stairs) | 34–38 in. above nosing |
| Handrail grip | Type I or II per IRC R311.7.8.5 |
Stairs and Bottom Landing#
Per IRC R311.7. Single stair run, exits the east (right) side of the deck.
| Parameter | Value |
|---|---|
| Stair location | East side of deck; opening in east rim from 67" to 103" from the house |
| Stair width | 36" minimum (IRC R311.7.1) |
| Total rise | ~30" (matches deck-to-grade design height) |
| Risers | 4 risers × 7.5" (≤ 7¾" max per R311.7.5.1) |
| Treads | 3 treads × 11" run (≥ 10" min per R311.7.5.2) |
| Riser/tread uniformity | ≤ ⅜" variation between risers and between treads |
| Nosing | ¾" min. to 1¼" max. projection (R311.7.5.3) |
| Stringers | (3) 2×12 PT SP #2, notched, 16" o.c. clear |
| Stringer-to-deck rim | Simpson LSC stair stringer connector at top, (2) per stringer |
| Stringer-at-landing | Bottom of stringer sits on a PT 2×6 kicker plate that bears on the compacted aggregate base beneath the paver finish. Pavers are finish surface only, not structural support. Kicker is anchored to the aggregate base to prevent lateral movement only (not for vertical load transfer); galvanized angle bracket ties stringer to kicker. |
| Treads / risers (finish) | 5/4×6 or 2×6 PT decking to match deck; closed risers |
| Handrail | Both sides, 34"–38" above tread nosings, Type I graspable profile, continuous, returns at both ends (R311.7.8) |
| Guardrail on open side | 34" min. above nosings, 4" sphere rule on infill (R312.1.2 / R312.1.3) |
| Bottom landing | 36" × 36" paver pad, level, on 4" compacted gravel base (R311.7.6) |
Clipped-Corner Framing#
The two outer corners (opposite the house) are clipped diagonally — 23" hypotenuse, ~16.3" along each leg. Framing follows the clipped shape structurally, not as a trim-only detail.
| Parameter | Value |
|---|---|
| Clip hypotenuse (angled rim joist length) | 23" |
| Clip legs (setback along each edge) | ~16.3" (16-⅜" nominal) |
| Angled rim joist | 2×8 PT SP #2, mitered at 45° at both ends |
| Angled rim joist to perimeter rim | 45° miter joint, fastened with (2) Simpson SDWS22500DB structural screws per side + construction adhesive |
| Outer joist (shortest) → angled rim | Simpson LSSU210 skewed hanger (45° left or right, matched to clip orientation) |
| Joists in clipped region | Progressively shortened; terminate at the angled rim joist rather than the perpendicular outer rim |
| Decking at clip | Mitered to follow the angled rim — no cantilever past the rim |
Framing Drawing#
SVG drawing above is schematic and to scale; all specified dimensions govern over drawing measurements. The ledger (bottom / south edge) is attached to the house rim joist. The clipped corners, both at the north (outer) edge, are framed structurally with 23" mitered rim joists per the Clipped-Corner Framing section above. The stair opening is on the east rim, 36" wide, beginning 67" from the house; see the Stairs and Bottom Landing section for stair framing.