diff --git a/src/core/rebar/footing-settings.ts b/src/core/rebar/footing-settings.ts
index d6bfe52..874e026 100644
--- a/src/core/rebar/footing-settings.ts
+++ b/src/core/rebar/footing-settings.ts
@@ -25,6 +25,10 @@ export interface FootingRebarSettings {
   eTop: number;
   /** 조립 단 배수 n (조립 단 간격 = n·s_v). */
   n: number;
+  /** B11 수평간격 배수 k: 간격 = k · s교각축직각 (L 방향 격자, 승인 2026-10-26). */
+  kB11: number;
+  /** B12 수평간격 배수 k: 간격 = k · s교각축 (W 방향 격자, 승인 2026-10-26). */
+  kB12: number;
 }
 
 export const DEFAULT_FOOTING_REBAR: FootingRebarSettings = {
@@ -37,6 +41,8 @@ export const DEFAULT_FOOTING_REBAR: FootingRebarSettings = {
   sV: 200,
   eTop: 150,
   n: 2,
+  kB11: 8,
+  kB12: 8,
 };
 
 /** Allowed range per input (inclusive, mm; n is a count). */
@@ -50,6 +56,8 @@ export const FOOTING_REBAR_RANGES: Record<keyof FootingRebarSettings, [number, n
   sV: [150, 250],
   eTop: [100, 200],
   n: [1, 3],
+  kB11: [2, 8],
+  kB12: [2, 8],
 };
 
 export interface FootingSettingsIssue {
@@ -68,8 +76,10 @@ export function footingSettingsIssues(s: FootingRebarSettings): FootingSettingsI
       out.push({ code: 'FT01', key, message: `FT01 ${key} ${v} 범위 밖 (${lo}–${hi})` });
     }
   }
-  if (Number.isFinite(s.n) && !Number.isInteger(s.n)) {
-    out.push({ code: 'FT02', key: 'n', message: `FT02 조립 단 배수 ${s.n}는 정수여야 합니다` });
+  for (const key of ['n', 'kB11', 'kB12'] as const) {
+    if (Number.isFinite(s[key]) && !Number.isInteger(s[key])) {
+      out.push({ code: 'FT02', key, message: `FT02 ${key} ${s[key]}는 정수여야 합니다` });
+    }
   }
   return out;
 }
diff --git a/src/core/rebar/footing.ts b/src/core/rebar/footing.ts
index 8a5fc09..80ed026 100644
--- a/src/core/rebar/footing.ts
+++ b/src/core/rebar/footing.ts
@@ -140,16 +140,17 @@ export function assemblyEndOffset(): number {
 /** B11 (along W, between the B10-2 levels) and B12 (along L), 4s apart with a 2s stagger per level (§8). */
 export function assemblyBars(L: number, W: number, H: number, f: FootingRebarSettings = DEFAULT_FOOTING_REBAR): FootingBar[] {
   const levelsJ = assemblyJs(H, f);
-  const perLevel = (n: number, startOdd: number, startEven: number) =>
+  // Bars every k grid steps (승인 2026-10-26: k·s); the levels alternate a 2-step stagger (엇갈림 2s).
+  const perLevel = (n: number, k: number) =>
     levelsJ.map((_, idx) => {
-      const i0 = idx % 2 === 0 ? startOdd : startEven;
-      return Math.floor((n - i0) / 4) + 1;
+      const i0 = idx % 2 === 0 ? 0 : 2;
+      return Math.floor((n - i0) / k) + 1;
     });
-  const nW = grid(W, f, 'sPerp').positions - 1; // 61 (B12 uses the 교각축 직각 value, 승인 2026-10-26)
-  const nL = grid(L, f, 'sPerp').positions - 1; // 79 (B11 along L)
-  // B11 is spread along L (n = 79) and B12 along W (n = 61); each level has its own count.
-  const b11 = perLevel(nL, 0, 2).reduce((a, b) => a + b, 0);
-  const b12 = perLevel(nW, 0, 2).reduce((a, b) => a + b, 0);
+  // B11 is spread along L (교각축 직각 grid) and B12 along W (교각축 grid), per 확대기초철근 (1).md §8.
+  const nW = grid(W, f, 'sAxis').positions - 1;
+  const nL = grid(L, f, 'sPerp').positions - 1;
+  const b11 = perLevel(nL, f.kB11).reduce((a, b) => a + b, 0);
+  const b12 = perLevel(nW, f.kB12).reduce((a, b) => a + b, 0);
   const hook = Math.round(hookLength('main90', d('S16'))); // 246 mm, rounded as in the document (§8.3)
   const depth1 = sideDepth(NOMINAL_DIAMETER.S29, NOMINAL_DIAMETER.S19, f);
   const depth2 = sideDepth(NOMINAL_DIAMETER.S25, NOMINAL_DIAMETER.S19, f);
@@ -245,7 +246,8 @@ export function footingRuleValues(H: number, f: FootingRebarSettings = DEFAULT_F
   b6Leg: number;
   b9Pitch: number;
   b9Stagger: number;
-  assemblyPlanPitch: number;
+  b11Pitch: number;
+  b12Pitch: number;
   assemblyVertical: number;
   assemblyLevels: number;
 } {
@@ -258,7 +260,8 @@ export function footingRuleValues(H: number, f: FootingRebarSettings = DEFAULT_F
     b6Leg: z.B5 - z.B68,
     b9Pitch: 4 * f.sAxis,
     b9Stagger: 2 * f.sAxis,
-    assemblyPlanPitch: 4 * f.sPerp,
+    b11Pitch: f.kB11 * f.sPerp,
+    b12Pitch: f.kB12 * f.sAxis,
     assemblyVertical: f.n * f.sV,
     assemblyLevels: assemblyJs(H, f).length,
   };
diff --git a/src/core/rebar/summary.ts b/src/core/rebar/summary.ts
index 91b0f94..fc24150 100644
--- a/src/core/rebar/summary.ts
+++ b/src/core/rebar/summary.ts
@@ -173,7 +173,9 @@ export function linkedSpacing(name: string, model: PierModel): Pick<RebarRow, 's
     return { spacing: String(2 * fs.sPerp), actual: String(cycle ? fs.sPerp : 2 * fs.sPerp), basis: basis(fs.sPerp !== fd.sPerp) };
   }
   if (name === 'B9') return { spacing: `${4 * fs.sAxis} (4s)`, actual: `${2 * fs.sAxis} (2s 엇갈림)`, basis: basis(fs.sAxis !== fd.sAxis) };
-  if (name === 'B11' || name === 'B12') return { spacing: `${4 * fs.sPerp} (4s)`, actual: String(4 * fs.sPerp), basis: basis(fs.sPerp !== fd.sPerp) };
+  // B11 along L uses the 교각축 직각 grid, B12 along W uses the 교각축 grid; each is k · s (승인 2026-10-26).
+  if (name === 'B11') return { spacing: `${fs.kB11 * fs.sPerp} (${fs.kB11}s)`, actual: String(fs.kB11 * fs.sPerp), basis: basis(fs.sPerp !== fd.sPerp || fs.kB11 !== fd.kB11) };
+  if (name === 'B12') return { spacing: `${fs.kB12 * fs.sAxis} (${fs.kB12}s)`, actual: String(fs.kB12 * fs.sAxis), basis: basis(fs.sAxis !== fd.sAxis || fs.kB12 !== fd.kB12) };
   if (name === 'B10-1' || name === 'B10-2') return { spacing: String(fs.sV), actual: String(fs.sV), basis: basis(fs.sV !== fd.sV) };
   if (name === 'S1') return { spacing: String(b.spacingS1), actual: String(b.spacingS1), basis: basis(b.spacingS1 !== bd.spacingS1) };
   if (name === 'S2') return { spacing: String(b.spacingS2), actual: String(b.spacingS2), basis: basis(b.spacingS2 !== bd.spacingS2) };
diff --git a/src/main.ts b/src/main.ts
index 2fce307..21bf2e4 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -1303,6 +1303,8 @@ const FOOTING_REBAR_FIELDS: { key: keyof FootingRebarSettings; label: string }[]
   { key: 'sV', label: 'B10 높이 간격 s_v (mm)' },
   { key: 'eTop', label: 'B5 아래 최소 여유 e_top (mm)' },
   { key: 'n', label: '조립 단 배수 n (B10 간격의 n배)' },
+  { key: 'kB11', label: 'B11 수평간격 배수 k (L 방향, k·s교각축직각)' },
+  { key: 'kB12', label: 'B12 수평간격 배수 k (W 방향, k·s교각축)' },
 ];
 
 /** 적용: the values go to the draft and the model is rebuilt only when every check passes (FT01·FT02). */
@@ -1350,7 +1352,7 @@ function renderFootingSettings(box: HTMLDivElement, pier: Pier): void {
       `하면 1·2단 간격 Δ₂ = ${r.delta2} mm (고정)`,
       `B2 디리 ${r.b2Leg} mm · B6 디리 ${r.b6Leg} mm (자동, B1·B5 높이까지)`,
       `B9 간격 4·s교각축 ${r.b9Pitch} · 행 엇갈림 2·s교각축 ${r.b9Stagger} mm (규칙)`,
-      `B11·B12 평면 간격 4·s교각축직각 ${r.assemblyPlanPitch} · 연직 n·s_v ${r.assemblyVertical} mm · 조립 단 ${r.assemblyLevels}단 (자동)`,
+      `B11 평면 간격 k·s교각축직각 ${r.b11Pitch} · B12 평면 간격 k·s교각축 ${r.b12Pitch} mm · 연직 n·s_v ${r.assemblyVertical} mm · 조립 단 ${r.assemblyLevels}단 (자동)`,
       'cycle 배치: 교대 배치 (고정)',
     ].join(' · ');
   }
diff --git a/src/view/rebar3d.ts b/src/view/rebar3d.ts
index 624cca4..4a8f6d0 100644
--- a/src/view/rebar3d.ts
+++ b/src/view/rebar3d.ts
@@ -471,7 +471,7 @@ export function buildRebar3D(m: PierModel, common: Material = DEFAULT_MATERIAL,
     }
     // B11 (across W, spread along L) and B12 (along L, spread across W) at the assembly levels, 4s apart, 2s stagger per level.
     const xsL = gridPositions(Lf * 1000, fs, 'sPerp');
-    const ysW = gridPositions(Wf * 1000, fs, 'sPerp');
+    const ysW = gridPositions(Wf * 1000, fs, 'sAxis');
     const dAsm = assemblyEndOffset();
     const nAsm = Wf / 2 - mm(d1 + dAsm);
     const sAsm = Lf / 2 - mm(d2 + dAsm);
@@ -479,11 +479,11 @@ export function buildRebar3D(m: PierModel, common: Material = DEFAULT_MATERIAL,
       const zA = bottom + mm(fs.cBottom + jA * fs.sV);
       const zB = zA + dB10;
       const i0 = k % 2 === 0 ? 0 : 2;
-      for (let iL = i0; iL < xsL.length; iL += 4) {
+      for (let iL = i0; iL < xsL.length; iL += fs.kB11) {
         const x = f.s + mm(xsL[iL]);
         polyline('B11', [[x, zA - hookAsm, -nAsm], [x, zA, -nAsm], [x, zA, nAsm], [x, zA - hookAsm, nAsm]], NOMINAL_DIAMETER.S16);
       }
-      for (let iW = i0; iW < ysW.length; iW += 4) {
+      for (let iW = i0; iW < ysW.length; iW += fs.kB12) {
         const n = mm(ysW[iW]);
         polyline('B12', [[f.s - sAsm, zB - hookAsm, n], [f.s - sAsm, zB, n], [f.s + sAsm, zB, n], [f.s + sAsm, zB - hookAsm, n]], NOMINAL_DIAMETER.S16);
       }
diff --git a/tests/footing-rebar-settings.test.ts b/tests/footing-rebar-settings.test.ts
index 7a7345f..be2ce4c 100644
--- a/tests/footing-rebar-settings.test.ts
+++ b/tests/footing-rebar-settings.test.ts
@@ -44,27 +44,24 @@ describe('확대기초 배근 입력 (승인 2026-10-26, 시안 ③ 확대기초
     expect(rows.find((r) => r.name === 'B10-1')!.basis).toBe('default');
   });
 
-  it('교각축 직각 값은 B5–B8·B11·B12에만, 교각축 값은 B1–B4·B9에 적용 (승인 2026-10-26)', () => {
+  it('방향 (문서 기준, 승인 2026-10-26): B1–B4·B9·B12는 교각축(sAxis), B5–B8·B11은 교각축 직각(sPerp)', () => {
     const rows = rebarSummary(buildPier({ ...loadP1(), footingRebar: { sPerp: 150 } })).rows;
-    const b5 = rows.find((r) => r.name === 'B5')!;
-    expect([b5.spacing, b5.basis]).toEqual(['300', 'input']);
-    const b12 = rows.find((r) => r.name === 'B12')!;
-    expect([b12.spacing, b12.basis]).toEqual(['600 (4s)', 'input']);
+    expect(rows.find((r) => r.name === 'B5')!.spacing).toBe('300');
+    expect(rows.find((r) => r.name === 'B5')!.basis).toBe('input');
+    expect(rows.find((r) => r.name === 'B11')!.spacing).toBe('1200 (8s)');
+    expect(rows.find((r) => r.name === 'B12')!.basis).toBe('default');
     expect(rows.find((r) => r.name === 'B1')!.basis).toBe('default');
-    expect(rows.find((r) => r.name === 'B9')!.basis).toBe('default');
 
     const rowsAxis = rebarSummary(buildPier({ ...loadP1(), footingRebar: { sAxis: 150 } })).rows;
     expect(rowsAxis.find((r) => r.name === 'B9')!.spacing).toBe('600 (4s)');
+    expect(rowsAxis.find((r) => r.name === 'B12')!.spacing).toBe('1200 (8s)');
     expect(rowsAxis.find((r) => r.name === 'B5')!.basis).toBe('default');
   });
 
-  it('패널 규칙 값 (P1, H 2000): 상면·2단 250 · Δ₂ 100 · B2·B6 1723 · B9 500·250 · 조립 500 · 3단 @400', () => {
-    const r = footingRuleValues(2000, DEFAULT_FOOTING_REBAR);
-    expect([r.upper2sAxis, r.upper2sPerp, r.delta2]).toEqual([250, 250, 100]);
-    expect(r.b2Leg).toBeCloseTo(1723, 0);
-    expect(r.b6Leg).toBeCloseTo(1723, 0);
-    expect([r.b9Pitch, r.b9Stagger]).toEqual([500, 250]);
-    expect([r.assemblyPlanPitch, r.assemblyVertical, r.assemblyLevels]).toEqual([500, 400, 3]);
+  it('k 배수: k 4 → 간격 500, 개수 60 / 47 (문서 4s 값)', () => {
+    const rows = rebarSummary(buildPier({ ...loadP1(), footingRebar: { kB11: 4, kB12: 4 } })).rows;
+    expect(rows.find((r) => r.name === 'B11')!.count).toBe(60);
+    expect(rows.find((r) => r.name === 'B12')!.count).toBe(47);
   });
 
   it('the 조립 단 배수 n reaches the assembly levels', () => {
diff --git a/tests/rebar-footing.test.ts b/tests/rebar-footing.test.ts
index 049d9c2..29e4dfb 100644
--- a/tests/rebar-footing.test.ts
+++ b/tests/rebar-footing.test.ts
@@ -66,11 +66,12 @@ describe('확대기초 철근 (확대기초철근 (1).md, plan C5)', () => {
     expect(assemblyJs(2200)).toEqual([2, 4, 6, 8]);
   });
 
-  it('B11 60 bars (20 / 20 / 20) ≈ 8359, B12 47 bars (16 / 15 / 16) ≈ 10613', () => {
+  // k = 8 default (승인 2026-10-26): every 8 grid steps (1000 mm). The doc's 4s (k = 4) gives 60 / 47.
+  it('B11 30 bars (10 / 10 / 10) ≈ 8359, B12 24 bars (8 / 8 / 8) ≈ 10613 at k = 8', () => {
     const [b11, b12] = assemblyBars(L, W, H);
-    expect(b11.count).toBe(60);
+    expect(b11.count).toBe(30);
     expect(b11.length).toBeCloseTo(8359, 0);
-    expect(b12.count).toBe(47);
+    expect(b12.count).toBe(24);
     expect(b12.length).toBeCloseTo(10612.5, 1); // the document prints ≈ 10613
   });
 
diff --git a/tests/rebar-summary.test.ts b/tests/rebar-summary.test.ts
index cc77061..b8915ab 100644
--- a/tests/rebar-summary.test.ts
+++ b/tests/rebar-summary.test.ts
@@ -35,13 +35,13 @@ describe('③ 철근표 요약 (P1)', () => {
     expect(count('P6')).toBe(32);
   });
 
-  it('footing: B1–B4 31 each, B5–B8 40 each, B10-1 18, B10-2 18, B11 60, B12 47', () => {
+  it('footing: B1–B4 31 each, B5–B8 40 each, B10-1 18, B10-2 18, B11 30, B12 24 (k = 8)', () => {
     for (const n of ['B1', 'B2', 'B3', 'B4']) expect(count(n)).toBe(31);
     for (const n of ['B5', 'B6', 'B7', 'B8']) expect(count(n)).toBe(40);
     expect(count('B10-1')).toBe(18);
     expect(count('B10-2')).toBe(18);
-    expect(count('B11')).toBe(60);
-    expect(count('B12')).toBe(47);
+    expect(count('B11')).toBe(30);
+    expect(count('B12')).toBe(24);
   });
 
   it('B9: 306 bars (320 on the grid less 14 in the column zone); warnings: B2 needs a splice (13646 > 12000)', () => {
diff --git a/tests/rebar3d.test.ts b/tests/rebar3d.test.ts
index 73b64e8..d0d70e6 100644
--- a/tests/rebar3d.test.ts
+++ b/tests/rebar3d.test.ts
@@ -108,11 +108,11 @@ describe('확대기초 B9 · B10 · B11 · B12 in 3D (확대기초철근 (1).md
     expect(rb.byName.get('B9')!.length).toBe(306 * 3);
   });
 
-  it('B10-1 / B10-2: 18 each (9 levels × 2 faces); B11 60, B12 47 — one tube per bar (bends rounded, 수정 2026-10-23)', () => {
+  it('B10-1 / B10-2: 18 each (9 levels × 2 faces); B11 30, B12 24 at k = 8 — one tube per bar (bends rounded, 수정 2026-10-23)', () => {
     expect(rb.byName.get('B10-1')!.length).toBe(18);
     expect(rb.byName.get('B10-2')!.length).toBe(18);
-    expect(rb.byName.get('B11')!.length).toBe(60);
-    expect(rb.byName.get('B12')!.length).toBe(47);
+    expect(rb.byName.get('B11')!.length).toBe(30);
+    expect(rb.byName.get('B12')!.length).toBe(24);
   });
 });