How to determine plumb, level, and square.

Follow our helpful process here to make your next project a success and ensure your door installation goes smoothly.

 

Time Required: Icon_Time2_15m_30m_85gray-1 Difficulty: Icon_DiffLevel1_85gray-1

 


Tools Required

  1. Safety glasses Icon_SafetyGlasses_85gray-1
  2. 2-foot level Icon_2ftLevel_85gray-1
  3. 6-foot level Icon_6ftLevel_85gray-1
  4. Tape measure (at least 10 ft) Icon_TapeMeasurer_85gray-1

 

Step 1) Check that the unit is plumb (internal jamb)

PlumbLevelSquareStep1A

PlumbLevelSquareStep1B

Start by opening the door, and placing the 6-foot level along the internal jamb.

PlumbLevelSquareStep1C

The jamb is level if the measurement shown above reflects your own level.

PlumbLevelSquareStep1D

Repeat the process on the opposite jamb.

Step 2) Check that the unit is plumb (exterior jamb)

PlumbLevelSquareStep2A

Place the 6 foot level along the exterior jamb, the side running parallel to the face of your door. 

PlumbLevelSquareStep1C

Ensure that the jamb is level.

PlumbLevelSquareStep3C

PlumbLevelSquareStep2B

Repeat this process on the opposite exterior jamb.

 

Step 3) Check head jamb for level

PlumbLevelSquareStep3A

Place the 2-foot level against the head jamb to check the level.

PlumbLevelSquareStep3B

If the head jamb is level, it will look like this.

 

Step 4) Check the sill (threshold) for level

PlumbLevelSquareStep4A

Place the 2-foot level against the sill of the door to check if it is level.

PlumbLevelSquareStep3B

If the sill is level, it should look like this.

 

Step 5) Check for square with diagonal measurements

PlumbLevelSquareStep5A

PlumbLevelSquareStep5B

You may need a partner to accomplish this task. Place the end of the tapemasure in the corner of the doorway where the jamb and sill meet.

PlumbLevelSquareStep5C

Then extend the tape measure diagonally across the doorway to measure the distance across in the opposite corner where the head jamb and opposite jamb meet. 

PlumbLevelSquareStep5D

Repeat this process in the opposite corners to get the second measurement. Your unit is square if both measurements are the same.

PlumbLevelSquareStep5E

PlumbLevelSquareStep5F

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