How to Check if a Crack is Level

You can do a quick check to see whether a crack is level (flush) or uneven using a straight edge.

What You’ll Need

• A straight-edged blade or flat edge (e.g. scraper blade, ruler, or similar)

Step-by-Step

1. Place the Blade Across the Crack
   Hold the blade perpendicular (at a right angle) to the crack so it across the crack.

2. Slide Across the Surface
   Gently move the blade across the crack from left to right in one smooth motion completely off the crack in either direction.

3. Feel for Resistance

   • If the blade glides smoothly with no catching, the crack is likely level.

   • If the blade catches, taps, or lifts, the crack is uneven.

   • If it glides one way but catches the other, this indicates a height difference across the crack (not flush).

4. Check Multiple Points
   Test along different sections of the crack, as the level can vary across its length.

What This Means

• Smooth both ways → Level crack (generally better outcome repair)

• Catching or uneven movement → Uneven crack (may require more involved repair and give more visible results)