diff --git a/src/hooks/roofcover/useRoofAllocationSetting.js b/src/hooks/roofcover/useRoofAllocationSetting.js
index f93e230d..3ebaa56c 100644
--- a/src/hooks/roofcover/useRoofAllocationSetting.js
+++ b/src/hooks/roofcover/useRoofAllocationSetting.js
@@ -473,7 +473,20 @@ export function useRoofAllocationSetting(id) {
             // Filter out any eaveHelpLines that are already in lines to avoid duplicates
             const existingEaveLineIds = new Set(roofBase.lines.map((line) => line.id))
             const newEaveLines = roofEaveHelpLines.filter((line) => !existingEaveLineIds.has(line.id))
-            roofBase.lines = [...newEaveLines]
+            // Filter out lines from roofBase.lines that share any points with newEaveLines
+            const linesToKeep = roofBase.lines.filter(roofLine => {
+              return !newEaveLines.some(eaveLine => {
+                // Check if any endpoint of roofLine matches any endpoint of eaveLine
+                return (
+                  // Check if any endpoint of roofLine matches any endpoint of eaveLine
+                  (Math.abs(roofLine.x1 - eaveLine.x1) < 0.1 && Math.abs(roofLine.y1 - eaveLine.y1) < 0.1) || // p1 matches p1
+                  (Math.abs(roofLine.x2 - eaveLine.x2) < 0.1 && Math.abs(roofLine.y2 - eaveLine.y2) < 0.1)    // p2 matches p2
+                );
+              });
+            });
+
+// Combine remaining lines with newEaveLines
+            roofBase.lines = [...linesToKeep, ...newEaveLines];
           } else {
             roofBase.lines = [...roofEaveHelpLines]
           }