How to Design a Wood Shear Wall — A Complete Step-by-Step Guide (SDPWS 2021 & ASCE 7-22)

A beam tells you when it is undersized — it sags, it cracks a ceiling, somebody calls. A shear wall keeps its opinion to itself until the one afternoon the design earthquake or the design windstorm arrives, and then the whole lateral system gets graded at once: the sheathing nails, the hold-downs, the sill bolts, the little framing clips nobody drew. A shear wall is not a member; it is a chain of five connections wrapped around a piece of plywood, and the chain is graded by its weakest link.

This guide designs that whole chain, start to finish, on one real building — and like every honest design story, the first trial fails. The wall line everyone would sketch first comes out at a demand/capacity ratio of 196%, and the obvious fix (nail it harder) walks you straight into a code clause that changes the framing under the nails. You will see the three levers available — tighter nails, a thicker panel, more wall — what each one buys, what each one costs, and why the cheapest fix is usually the one drawn last.

Along the way this page carries the lesson most shear wall tutorials skip entirely: wind and seismic do not distribute to the same walls in the same proportions. On this building, the garage piers pass their seismic check at 88% — and fail their wind check at 103%. Size them from a single "share of V" and you ship that failure.

By the end you will have: the finished shear wall schedule for all three lines, every check with its substituted formula and code citation, the hold-down and end-post selections, the complete base anchorage (bolts on concrete, clips over framing), the drift calculation, the construction mistakes that undo all of it on site, and a full hand-calculation verification table. Every number below was produced by the calculation engine that runs StructSuite's Wood-Frame Shear Wall module and locked by automated regression tests; the hand-verification is at the end of the page.

#The building we are going to design

A single-story wood-framed house on an L-shaped plan: a 60 × 30 ft main body and a 30 × 20 ft wing, walls 9 ft tall, in Seismic Design Category D (S_DS = 1.0 g, redundancy ρ = 1.0). The lateral analysis — which you can reproduce with our seismic base shear guide and wind load guide — delivered, per principal direction:

The walls carry a light roof: D = 400 plf of dead load and Lr = 200 plf of roof live load land on top of every shear wall line. The east–west direction is the one we will design — three wall lines resist it:

• Line 1 — the back wall of the body (on the concrete stem wall);
• Line 2 — the wall at the step between body and wing;
• Line 3 — the front of the wing: two narrow piers beside the garage door, sitting on the framed floor of a split-level (this detail will matter twice).

Sheathing everywhere is the most ordinary product in the industry: 7/16″ wood structural panel (OSB) sheathing with 8d common nails — Table 4.3A's bread-and-butter row. The design questions are the ones every job has: how much wall does each line need, at what nail spacing, held down by what, bolted with what?

#How a shear wall works — the load path is the design

Lateral force enters at the roof. The roof deck — the diaphragm — spans horizontally like a wide, flat beam between the shear wall lines, and each line receives a share of the story force V as a horizontal reaction at its top. From there every wall in the line does the same four jobs at once:

1. Shear — the panel-and-nails assembly drags the force down to the base; its currency is unit shear, v = V/b (plf).
2. Overturning — V at the top of a wall of height h creates a moment V·h that tries to tip the wall; a hold-down at the uplift end and an end post at the compression end resist the couple.
3. Base shear transfer — the sill or bottom plate must hand the same v to whatever is below: anchor bolts into concrete, or framing clips into floor framing.
4. Gravity — the same wall is usually also a bearing wall; the dead load helps overturning and punishes the compression post.

Each of those four jobs is a numbered step below, and each one has its own code home. That map is worth pinning to the wall:

One basis note before any numbers, because it silently controls everything: this design runs in ASD. ASCE 7-22 wind and seismic forces arrive at strength level; the allowable-stress combinations scale them — wind enters at 0.6W, seismic at 0.7E — and SDPWS hands you nominal sheathing capacities meant to be divided by 2.0 for wind and 2.8 for seismic (§4.1.4.1, §4.1.4.2, "no further increases shall be permitted"). Demand and capacity must land on the same side of that conversion. Every mismatched shear wall calc ever red-lined got this pairing wrong somewhere.

#Step 1 — The story forces, and what "E" and "W" mean here

From the lateral analysis: E = 25,000 lb and W = 30,000 lb per direction, strength level, applied at the roof line. Three things ride along with them:

• ρ (redundancy): seismic combinations use E_h = ρ·E. Our building qualifies for ρ = 1.0; a torsionally weak or single-line building can carry ρ = 1.3, and it multiplies every seismic number below.
• E_v (vertical seismic): ±0.2·S_DS·D accompanies E_h in the §2.4.5 combinations. It looks like a rounding detail until it reaches the hold-downs: in combination 10 it subtracts from the dead load that resists uplift.
• The wind is not "smaller" because 30,000 > 25,000·0.6/0.7: which case governs depends on the line, because the two forces distribute differently — that is Step 2, and it is the heart of this guide.

#Step 2 — Distribute the story force to the wall lines (both cases, always)

For wood diaphragms the standard idealization is the flexible diaphragm: the roof spans like a simple beam between wall lines, and each line collects the load from the strip of building tributary to it — halfway to the neighboring line on each side. That much is familiar. What surprises engineers on irregular plans is that wind and seismic do not split the same way across the same walls, because they are different physics:

• Seismic force is inertia. It is generated wherever there is mass, and for a uniform roof the mass in a line's tributary strip is proportional to the strip's area.
• Wind force is pressure on the projected face of the building. Along the span it arrives per foot of building depth, so a line's share is proportional to its tributary length of the span — the plan being locally wide adds mass, but it adds no wind.

On a clean rectangle the two measures agree and nobody notices. On our L-shape they diverge, and one line will fail because of it. The tributary boundaries fall midway between lines: at y = 15 ft and y = 40 ft.

Seismic — share by tributary area (uniform roof mass):

Wind — share by tributary length of the 50-ft span (pressure on the projected face arrives per foot of depth; local plan width is irrelevant):

Same walls, same story — two different splits. Look at line 3: 12.5% of the seismic force but 20% of the wind — a 60% larger share of the wind case, because the wing is shallow in plan: little mass, but its full slice of the projected face. Line 1 leans the other way. Hold that thought; it detonates in Step 6.

Both distributions above (and every share in this guide) come from StructSuite's plan-driven distribution engine, which always computes both cases — in the module you draw this plan once and every line's caption reads like "900 sf · E 38% · W 30%". The within-line and per-case arithmetic is locked by the same regression pins as this page.

#Step 3 — Choose the walls on each line, and respect the aspect ratio law

A wall line is rarely one long wall — it is the segments left over between windows and doors. Each full-height segment (SDPWS §4.3.2.1) works as its own shear wall of length b and height h, and the first legality check is pure geometry, from SDPWS 2021 Table 4.3.3 — Maximum Shear Wall Aspect Ratios:

with the table's own footnote 1: "Walls having aspect ratios exceeding 1.5:1 shall be blocked shear walls." At h = 9 ft, a blocked WSP segment may be as narrow as 9/3.5 = 2 ft 7 in. — but "may" is doing heavy lifting, because narrowness is taxed twice:

• §4.3.3.2 — for WSP walls with h/b > 2:1, multiply the nominal capacity by the Aspect Ratio Factor = 1.25 − 0.125·h/b;
• §4.3.5.5.1, Exception 1 — when segments of unequal stiffness share a line by the capacity-proportional simplification, a wall with h/b > 2:1 contributes with a 2b/h reduction instead. The engine computes both and takes whichever governs.

Our first-pass elevations, straight off the architect's plan:

Line 3's piers at h/b = 9/4 = 2.25 carry both penalties: Aspect Ratio Factor = 1.25 − 0.125(2.25) = 0.969, and Exception 1's 2b/h = 2(4)/9 = 0.889 — the smaller one, 0.889, governs. Every plf of tabulated capacity on those piers is worth 89 cents on the dollar before we start.

#Step 4 — Sheathing capacity: reading Table 4.3A like the engine does

SDPWS Table 4.3A tabulates nominal unit shear capacities v_n for wood-based panels, by panel type, thickness, nail, and edge-nail spacing (6″, 4″, 3″, 2″). Our row — 7/16″ WSP Sheathing, 8d common (2½″ × 0.131″) nails, 1⅜″ minimum penetration:

Two conversions stand between that row and a check:

Nominal → ASD (§4.1.4). Divide by 2.0 for wind (§4.1.4.2) or 2.8 for seismic (§4.1.4.1) — "no further increases shall be permitted", which retires the old habit of a 1.33 or 1.4 duration bump. At 4″ spacing: v_ASD,seismic = 980/2.8 = 350 plf, v_ASD,wind = 980/2.0 = 490 plf. Notice wind gets 40% more capacity from the same nails — remember that asymmetry when the two demands are close.

Per-wall, then per-line. Each segment's ASD capacity is (v_n/Ω)·(aspect factor)·b, and the line's capacity is the sum. The engine distributes the line force to segments in proportion to their design capacities (the §4.3.5.5.1 Exception 1 simplification) — so equal-height, equal-construction segments all run at the same unit shear, and a factored narrow pier automatically takes less.

Three footnotes on Table 4.3A earn their keep so often the module gives each a checkbox with the verbatim text (footnote-apply standard):

• Footnote 2: 8d rows may be upgraded to the 15/32″ values when the panel is 15/32″ — free capacity if you were already sheathing thicker.
• Footnote 3: framing other than Douglas Fir-Larch or Southern Pine multiplies v_n by the Specific Gravity Adjustment Factor = 1 − (0.5 − G) ≤ 1.0 — SPF framing (G = 0.42) knocks 8% off every number in this guide.
• Footnote 10: 10d rows take a 0.92 factor when the hold-down sits on the inside face of the end post.

We use none of them here — DF framing, 7/16″ panel, 8d nails — which is exactly why the trial that follows is as clean a failure as you will ever get.

#Step 5 — Design line 1: the trial that fails, and the three levers

Line 1's governing ASD demand is seismic — combination 8. D + 0.7E_v + 0.7E_h (ASCE 7-22 §2.4.5):

V_ASD = 0.7 × 9,375 = 6,562.5 lb, spread over Σb = 14 ft → v = 468.8 plf of demand.

Capacity at each nail spacing is (v_n/2.8) × Σb, and here is the whole trial in one table — the demand never moves; only the nails do:

The 6″ row is the one everyone sketches first, and it is not even close: 196%. Tightening nails looks like it works — 2″ spacing passes at 80% — but read the fine print before celebrating. SDPWS §4.3.7.1(5) requires the framing at adjoining panel edges to be 3x nominal (or two 2x stitched together) with staggered nailing when any of these is true: (a) edge nailing at 2″ o.c., (b) 10d common nails at 3″ o.c. or closer, or (c) nominal unit shear over 980 plf in Seismic Design Category D, E or F. Our 2″ trial trips (a) and (c). So does the "upgrade the hardware" lever: 15/32″ panels with 10d nails at 3″ o.c. reaches v_n = 1,680 → 600 plf ASD → D/C 78% — and trips (b) and (c). In SDC D, every nail-side path out of this failure converts the wall's studs at panel joints from 2x to 3x, with the plate splices, the special-inspection attention and the subcontractor phone calls that follow.

The lever study. Three ways out, priced honestly:

Lever C wins, and not just on cost: at 4″ spacing v_n = 980 plf sits exactly at the 980 threshold — "exceeds 980" it does not — so the whole line stays on ordinary 2x framing. That is not luck; it is why the 4″/980 row is the workhorse of high-seismic residential design. The cheapest shear wall fix is almost always length, not hardware. Fight for wall in the floor plan before you fight physics with nails.

Final line 1: three segments, 8 + 8 + 6 ft (Σb = 22 ft), 7/16″ WSP, 8d @ 4″/12″.

• Capacity: (980/2.8) × 22 = 350 × 22 = 7,700 lb → D/C = 6,562.5/7,700 = 85% ✓ (seismic governs; wind runs at 50%)
• Demand unit shear: v = 6,562.5/22 = 298.3 plf

#Step 6 — Line 3: the wind trap, sprung

Now the wing. Its seismic share was small — 12.5%, an ASD demand of 0.7 × 3,125 = 2,187.5 lb. Its wind share was not — 20%, an ASD demand of 0.6 × 6,000 = 3,600 lb. Run the two 4-ft piers (with their 0.889 aspect factor) through both cases at the spacing the seismic number suggests:

At 4″ spacing — capacity per case, Σ(v_n/Ω)·0.889·b over both piers:

• Seismic: (980/2.8) × 0.889 × 8 = 2,488.9 lb → D/C = 2,187.5/2,488.9 = 88% ✓ passes
• Wind: (980/2.0) × 0.889 × 8 = 3,484.4 lb → D/C = 3,600/3,484.4 = 103% ✗ FAILS

There it is. Sized by its seismic share alone, the garage front passes at 88% and ships. The wind share fails it at 103%. Nothing exotic happened — the wing is shallow (small mass, small E) but stands its full slice of the projected face (full W), and even wind's friendlier Ω = 2.0 cannot cover a 64% larger force on 11% less capacity. Any workflow that distributes one "share of V" — a spreadsheet with one tributary column, a rigid habit of "seismic always governs in SDC D" — ships this wall.

At 3″ spacing both cases clear comfortably:

• Wind: (1,260/2.0) × 0.889 × 8 = 4,480 lb → D/C = 3,600/4,480 = 80% ✓
• Seismic: (1,260/2.8) × 0.889 × 8 = 3,200 lb → D/C = 2,187.5/3,200 = 68% ✓

So line 3 ships at 8d @ 3″ — and pays two taxes that belong in the drawing notes: v_n = 1,260 > 980 plf in SDC D triggers §4.3.7.1(5c) 3x framing with staggered nailing wherever panel edges abut (here, the blocked horizontal joint at the 8-ft panel break and the abutting stud between panels), and the narrow piers keep their 0.889 aspect-ratio haircut forever.

#Step 7 — Line 2, and the finished shear schedule

Line 2 carries the largest forces of all (E_line = 12,500, W_line = 15,000 lb) on 20 ft of wall. At 4″ the seismic case fails (125%); at 3″ it works: capacity 450 × 20 = 9,000 lb against 0.7 × 12,500 = 8,750 lb → D/C 97% — tight, deliberate, and legal. (Wind: 71%.) Being over v_n = 980, line 2 also joins the 3x-framing club.

The line-by-line result — this is the table that becomes the drawing's shear wall schedule:

Within each line, the engine splits the line force among segments in proportion to design capacity (§4.3.5.5.1 Exc. 1): on line 1 that is 2,386.4 lb to each 8-ft wall and 1,789.8 lb to the 6-ft wall — all three at the same 298.3 plf, which is what "capacity-proportional" buys you. Those per-wall shears are the inputs to everything below the sheathing: hold-downs, posts, and the base.

#Step 8 — Overturning and hold-downs: where 0.6D and E_v earn their keep

Each wall's shear V acts at the top; V·h wants to rotate the wall out of its own footprint. What resists is the wall's tributary dead load — and the code deliberately shrinks it. The uplift check runs under combination 10: 0.6D − 0.7E_v + 0.7E_h (ASCE 7-22 §2.4.5): only 60% of the dead load may help, and the vertical seismic component E_v = 0.2·S_DS·D takes another bite — at S_DS = 1.0 the net multiplier is 0.6 − 0.7(0.2)(1.0) = 0.46D.

Worked for line 1's 6-ft wall (its 298.3 plf × 6 ft = 1,789.8 lb share):

• Overturning: M_OT = V·h = 1,789.8 × 9 = 16,107.9 lb·ft
• Resisting: the wall's dead load W_D = 400 × 6 = 2,400 lb acts at mid-length → M_R = 0.46 × 2,400 × 3 = 3,312 lb·ft
• Hold-down tension: T = (M_OT − M_R)/b = (16,107.9 − 3,312)/6 = 2,132.7 lb

The compression end is checked under the heaviest vertical case — combination 8 (D + 0.7E_v + 0.7E_h, net 1.14D):

• C = M_OT/b + R_end = 2,684.7 + 1.14 × (2,400/2) = 2,684.7 + 1,368 = 4,052.7 lb

Across the line, the 8-ft walls come out at T = 1,948.7 lb and C = 4,508.7 lb (their bigger V, but also more helping dead load). The worst hold-down demand on the line is the 6-ft wall's 2,132.7 lb — narrow walls punch above their weight on uplift, which is why hold-down schedules are set by the shortest segment, not the longest.

Selecting the hardware. Hold-down capacities are manufacturer allowables, by species column. Against 2,132.7 lb, the catalog's first qualifying device is a DTT2Z on a 3×3.5 post — 2,145 lb (DF/SP), (8) ¼″ × 1½″ SDS screws — at D/C 99.4%. That is a legal number and an uncomfortable one; one step up, an HDUE3-SDS3 gives 3,790 lb (56%) and room for the day the architect widens that window. Either way, note what the catalog is telling you in the fine print: the rated deflection at capacity (0.128″ for the DTT2Z) is not trivia — it is Δ_a in the drift equation of Step 12, and hold-down stretch is routinely the largest single term in wood shear wall drift.

Every segment end gets a hold-down in this design — SDPWS §4.3.6.4.2 requires uplift anchorage wherever the dead-load stabilizing moment cannot cover the overturning, and at 0.46D almost nothing residential covers it.

#Step 9 — The end post: the boring check that fails first on heavy walls

The compression end of each wall stacks C = M_OT/b + gravity end reaction into a stud pack. For line 1 we try the default: (2) 2×4 DF No. 2, braced by sheathing in-plane, buckling out-of-plane over l_e = 9 ft − plates = 103.5″, l_e/d = 29.6:

• Column capacity (NDS 3.7, C_P = 0.208 at this slenderness): P_allow = 5,438 lb
• Plate bearing (NDS 3.10, F_c⊥, no C_D): 6,563 lb
• Demand: worst C = 4,508.7 lb → D/C = 83% ✓ — column buckling governs, as it usually does at 9-ft walls.

Two habits worth stealing: check bearing and buckling every time (they trade places as h changes — bearing wins on short heavy walls, buckling on tall ones), and remember C_D = 1.6 applies to F_c but never to F_c⊥ (NDS Table 2.3.2). The full stability math — C_P, F_cE, the works — is the same machinery as our wood column guide; in the module it is Substep 4C, checked per wall in Step 5.

#Step 10 — Base shear transfer: the check most drawings skip

Everything so far moved the force to the bottom plate. It still has to leave the wall. SDPWS §4.3.6.4.1 says it plainly: "Connections shall be provided to transfer the unit shear force induced by the design load, v, into and out of each shear wall." Two substrates, two solutions:

Line 1 sits on concrete — sill anchor bolts. The wood side of a bolt in a DF sill comes from NDS 2024 Table 12E (single shear, sawn lumber to concrete, 6″ embedment assumed, f′_c ≥ 2,500 psi): a 5/8″ bolt in a 1½″ sill gives Z_∥ = 930 lb. Adjusted (NDS Table 11.3.1): Z′ = Z_∥ × C_D × C_M = 930 × 1.6 × 1.0 = 1,488 lb per bolt (C_g = 1.0 — each bolt carries its own tributary length of a distributed shear; C_Δ = 1.0 at any practical spacing).

At 48″ o.c.: demand per bolt = v × s = 298.3 × 48/12 = 1,193.2 lb → D/C = 80% ✓ (spacing could legally stretch to 59.9″, but 48″ ≤ the IBC 6-ft maximum with margin, and even spacing lays out cleanly on 8-ft walls). The prescriptive floor rides along regardless of calculation — IBC 2024 §2308.7.1: ½″ minimum diameter, 7″ embedment, two bolts per plate piece, one 4–12″ from each end — and SDPWS §4.3.6.4.3 adds the seismic-country signature: a 0.229″ × 3″ × 3″ steel plate washer under every nut, extending to within ½″ of the sheathed edge. Those washers are not bureaucracy; they are what stops the bottom plate from splitting in cross-grain bending before the bolts ever yield.

Line 3 sits on floor framing — framing clips. No toe-nail shortcut is available even if you wanted it: the piers' seismic unit shear is 273.4 plf, and SDPWS §4.1.10 bars toe-nailed connections above 150 plf (ASD) in SDC D, E and F. A mechanical clip is the code path. The governing unit shear is wind's 450 plf, and a Simpson A35 in its plates-to-rim configuration carries 650 lb in the catalog's (160) column — one column that serves wind and seismic alike, "no further increase allowed". At 16″ o.c.: demand per clip = 450 × 16/12 = 600 lb → D/C = 92% ✓ (required spacing ≤ 17.3″).

In the module this is Substep 4D: pick the substrate, pick the connection, and the required spacing falls out of the same v used everywhere else — with the SDPWS washer rule, the IBC minimums and the §4.1.10 gate printed beside the check, and the book icon quoting the code text verbatim.

#Step 11 — The collector, in one paragraph

The top plate that drags diaphragm shear across the 4-ft openings to the wall segments is a collector, and in SDC C–F seismic collectors are designed for the amplified Ω₀-level force (ASCE 7-22 §12.10.2.1, with the light-frame exception the module surfaces). On this line the double top plate has ample axial capacity; the point of this paragraph is that "check the collector" is a real line item — the module computes the drag diagram in Step 2 and checks it in Step 5, and skipping it is one of the six traps below.

#Step 12 — Drift: the check nobody asks for until the windows crack

Strength is not the only acceptance criterion — SDPWS §4.3.4.1 gives the deflection of a full-height segment (Equation 4.3-1):

δ_sw = 8vh³/(EAb) + vh/(1000·G_a) + h·Δ_a/b

— bending of the wall as a cantilever (chords), shear racking of the panel-and-nails (that is what G_a measures), and rigid-body rotation from anchorage stretch. For the 6-ft wall at its strength-level seismic shear (v = 426.1 plf), with (2) 2×4 DF chords (E = 1.6×10⁶ psi, A = 10.5 in²), G_a = 22 kips/in, and the DTT2Z's rated Δ_a = 0.128″:

Read the proportions, not just the total: the chords barely matter; nail slip and hold-down stretch are ~94% of the drift. That is why tightening nail spacing stiffens a wall as much as it strengthens it (G_a jumped from 15 to 22 when we left 6″ behind), and why a soft hold-down on a narrow wall is a drift problem before it is a strength problem. Amplify δ_sw per the ASCE 7-22 Chapter 12 drift provisions (C_d/I_e for your system row) and compare against the story-drift limit for your building — the module reports the strength chain; the drift comparison stays with you and your Table 12.2-1 row.

#Building it: what actually goes wrong on site

Every number above assumes the wall in the drawing is the wall that gets built. These are the failures inspectors actually find, in rough order of frequency:

• Over-driven nails. A gun set hot enough to bury heads through the face veneer of OSB can quietly delete a third of the wall's capacity — the head punches through instead of clamping. Specify flush-driven, and expect the inspector's fingernail test.
• Edge distance. Nails at 3/8″ minimum from panel edges; a nail split into the edge is a nail that is not there. On 3x framing at abutting edges, stagger the two panels' rows — that is what §4.3.7.1(5) is buying.
• Missing blocking. Table 4.3A is a blocked-wall table. An unblocked horizontal joint at the 8-ft panel line converts your 350 plf wall into something the table never promised.
• The washer that stayed on the truck. Standard cut washers under sill nuts in SDC D are a plan-check classic; the 0.229″ × 3″ × 3″ plates of §4.3.6.4.3 are the difference between bolt bearing and plate splitting.
• Hold-down stack-up. Devices installed over uncompressed shims, rods left finger-tight, or green lumber shrinking half a season later — every 1/16″ shows up as Δ_a, and Step 12 showed Δ_a is a fifth of the drift. Retighten after dry-in on shrinkage-critical jobs.
• The clip that vanished at framing. Base transfer hardware (our A35s) never makes it from the calc package to the framer unless it is on the schedule with a count and a spacing. Draw it like you mean it.

#Summary — the finished lateral design, east–west

#Verification — hand calculation against StructSuite

Every number on this page was computed twice: once by the StructSuite engine (locked by the V-SWG regression suite) and once by hand, long-form. The Δ column is the difference.

#Distribution and line shear

#Overturning, hold-down, end post

#Base transfer and drift

Agreement of arithmetic is what this proves — not judgment. The choices (three segments instead of two, 48″ bolts instead of 59″, a hold-down at 99% instead of 56%) remain engineering, and they remain yours.

#Six traps that sink shear wall designs

1. One split for two forces. Distributing a single "share of V" to walls that see both wind and seismic. This page's garage piers: 88% pass by seismic, 103% fail by wind.
2. The duration-factor double-dip. Applying C_D = 1.6 (or the old 1.33) on top of Table 4.3A values. §4.1.4's Ω = 2.0/2.8 already own that ground: "no further increases shall be permitted."
3. Full dead load resisting uplift. Hold-downs sized with 1.0D instead of 0.6D − 0.7E_v come out ~2.5× unconservative on this building's walls.
4. Blocked table, unblocked wall. Table 4.3A assumes every panel edge lands on framing or blocking. One unblocked joint and the tabulated value no longer describes the wall you built.
5. No path out of the wall. Sheathing and hold-downs designed, base transfer left to toe-nails — which §4.1.10 bars above 150 plf in SDC D–F. The v must land in bolts or clips, on the drawing, with a spacing.
6. The 980-plf surprise. Specifying 3″ or 2″ nailing in SDC D without noticing §4.3.7.1(5)'s 3x-framing requirement — discovered at rough framing inspection, fixed at time-and-materials.

#Frequently asked questions

#Why is the seismic reduction factor 2.8 but wind only 2.0?

Because the two hazards are treated with different reliability targets against a nominal capacity that comes from the same cyclic tests. The practical consequence is the one this guide leans on: the same wall has 40% more ASD capacity against wind, so wind can only govern where its distributed demand is enough larger — exactly what happens on shallow wings and stair towers.

#Do I really have to check both wind and seismic on every line, even in SDC D?

Yes — and not because of the cases' totals, but because of their splits. Seismic follows tributary mass (area); wind follows tributary length of the projected face. On any non-rectangular plan those differ line by line, and the governing case can flip between neighboring walls of the same building, as it does here.

#When does a shear wall have to be blocked?

Per SDPWS Table 4.3.3 footnote 1, any wall with h/b over 1.5:1 must be blocked, and the Table 4.3A capacities used in this guide are blocked-wall values. Unblocked walls exist in SDPWS with their own adjustment, but for engineered work the honest summary is: block the edges, nail the edges, and the table means what it says.

#How narrow can a wall segment be?

Blocked WSP: h/b ≤ 3.5:1 (Table 4.3.3) — at 9 ft, about 2′-7″. But above 2:1 the §4.3.3.2 factor (1.25 − 0.125·h/b) and the §4.3.5.5.1 Exception 1 factor (2b/h) shave the capacity, and the drift equation's h·Δ_a/b term grows. Narrow piers are legal; they are just expensive per plf.

#When do I need 3x framing at panel edges?

SDPWS §4.3.7.1(5): edge nailing at 2″ o.c.; 10d commons at 3″ o.c. or less; or nominal capacity over 980 plf in SDC D, E or F. That third trigger catches every 3″ row of the 7/16″ table in high-seismic work — plan for it before pricing, not after inspection.

#Do hold-downs go at every segment end?

Wherever the reduced dead load (0.6D − 0.7E_v) cannot cover the overturning — SDPWS §4.3.6.4.2. At S_DS = 1.0 that net 0.46D covers almost nothing residential; assume a device at both ends of every segment until a calculation says otherwise.

#Can toe-nails transfer the base shear?

Above 150 plf (ASD) in SDC D–F, no — §4.1.10. Below that, they still deserve suspicion: the clip's few dollars buy a tested, listed, inspectable connection.

#What if my framing is SPF instead of DF?

Table 4.3A footnote 3: multiply v_n by 1 − (0.5 − G). SPF at G = 0.42 gives 0.92 — every capacity in this guide drops 8%, and line 2's 97% stops passing. Species is not a footnote; it is a design input.

#What about openings — is there a method that skips hold-downs at every pier?

Yes: the perforated shear wall method (SDPWS §4.3.5.6, the C_o factor), which trades hardware for capacity. This guide uses the segmented method throughout because it is the transparent one — every pier's numbers are visible — and it is what the module implements.

#Where does the IBC come into this?

IBC 2024 §2305.1 delegates engineered wood lateral design to SDPWS, and keeps for itself the prescriptive minimums this page cited where they bind (sill bolt diameter, spacing, embedment — §2308.7.1 — and the SDC D/E washer and bolt upgrades).

#Design this building in StructSuite

Everything on this page is the Wood-Frame Shear Wall module doing its ordinary work: draw the L-shaped plan once and the module distributes both cases to every line; pick a line and Steps 2–6 design it — Table 4.3A with its footnotes verbatim, the aspect factors, per-wall overturning with 0.6D − 0.7E_v, hold-down and end-post checks, and Substep 4D's anchor bolts and framing clips with the code text one book-icon away. The sample project carries a complete plan-driven shear wall you can open without an account, and the method behind every number here is documented in How StructSuite Works.

Companion guides: seismic base shear (ASCE 7-22 §12.8) · wind loads, Chapter 27 · wood column design · NDS Supplement tables.