diff --git a/src/hooks/module/useTrestle.js b/src/hooks/module/useTrestle.js
index 761ce983..e2a40068 100644
--- a/src/hooks/module/useTrestle.js
+++ b/src/hooks/module/useTrestle.js
@@ -1060,7 +1060,8 @@ export const useTrestle = () => {
 
     const roof = canvas.getObjects().find((obj) => obj.id === surface.parentId)
     const degree = getDegreeByChon(roof.roofMaterial.pitch)
-
+    rackIntvlPct = rackIntvlPct === 0 ? 1 : rackIntvlPct // 0인 경우 1로 변경
+    rackIntvlPct = 100 / rackIntvlPct // 퍼센트로 변경
     const moduleLeft = lastX ?? left
     const moduleTop = lastY ?? top