All Things Inspectors Door Gap Gauge can be used to measure gaps on fire rated and If you need to learn how to use a door gauge.non-rated door assemblies with any style door. Whether the door and frame are of hollow metal, wood, aluminum or fiberglass construction.

Purchase your Door Gap Gauge today.

Below we outline how to use the Door Gap Gauge.

Step 1 Figure out what type of door and frame you are inspecting to pinpoint the required NFPA 80 requirements.

Top and Vertical Edge of Door Requirements:

  • For Steel Doors Swinging in pairs the clearance between the top and the vertical edges of the door, the frame, and the meeting edges shall be 1/8″ – 1/16″.
  • For Wood Doors Swinging in pairs the clearance between the top and vertical edges of the door, the frame and the meeting edges shall not exceed 1/8″.

Bottom of Door Requirements:

  • The clearance under the bottom of a door and non-combustible surface where no sill exists shall be a maximum of 3/4″.
  • The clearance under the bottom of a door and raised non-combustible sills shall be a maximum of 3/8″.

Now that you know the clearance requirements you are trying to measure you will move on to Step 2.

Step 2 Measure the gaps
Note: Measure all clearance dimensions on the pull side of the door

Measuring the Top and Vertical Edge of Door Requirements:

  • Grab you gauge and locate the step portion of the gauge with the dimension that you are looking to measure.
  • Place the gauge in your hand so you can insert the gauge between the door and the frame. The gauge should fit in the gap between the door and the frame, sliding along the entire length of the gap along the top and vertical edges.

Measuring the Bottom of Door Requirements:

  • Grab you gauge and locate the step portion of the gauge with the dimension that you are looking to measure.
  • Place the gauge in your hand so you can insert the gauge under the bottom of the door and take an accurate measurement.

Step 3 Verify that your door gaps fall within the required min and maximum requirement as required by NFPA 80 and adjust as required.

Step 4 If you still need some guidance we have a couple of how to use a door gap gauge videos that you can watch.

Thank you for taking a moment to learn how to use a door gap gauge.