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How to measure

Measure Roller Housing Width

Housing width is the metal cassette size side to side. It is the key fit dimension for most patio door rollers. Measure the housing, not the wheel.

Use Roller Finder All identify guides

What you need

  • Preferred: a rigid ruler marked in inches and fractions
  • Best accuracy: calipers for tight spaces
  • Acceptable: a tape measure if you can hold it straight and read fractions carefully

Step by step

  1. Support the door. Slide the operating panel toward the center. Have a helper if the panel is heavy.
  2. Retract the rollers. Find the adjustment hole at the bottom rail. Turn the screw counterclockwise until the door lifts slightly off the track.
  3. Remove the panel. Tilt the bottom toward you and lift the panel out of the track. Set it on a padded surface.
  4. Find the housing. Inside the bottom rail you will see a metal cassette with one wheel (single) or two wheels (tandem). That cassette is the roller housing.
  5. Slide the housing out. Remove the retaining screw or release the clip/tab, then pull the whole metal assembly free.
  6. Measure housing width. Turn the housing so you look at its narrow side, not the wheel face. Measure across the main metal body from one side plate to the opposite side plate. Ignore lips, tabs, and flanges that stick out.
  7. Write it down. Record the width in inches before you put the door back together.

Measure

  • Housing width: metal body side to side
  • Optional for expert help: housing height and length

Do not use as housing width

  • Wheel diameter
  • Wheel alone without the metal body
  • Tab length or hook depth
  • Overall housing length
  • Total thickness of housing plus wheel
  • The door rail opening instead of the housing itself

Common mistakes

  • Measuring wheel diameter and calling it width
  • Measuring housing plus wheel as one thickness
  • Using tab length as the width
  • Measuring the door pocket instead of the roller housing
  • Reading the tape at a slant so 11/16 looks like 5/8 or 3/4
  • Rounding to a whole inch (for example calling 13/16 “1 inch”)

Match a catalog size

Stay in inches and fractions. Round to the nearest common housing width used in our catalog:

  • 1/2″
  • 9/16″
  • 5/8″
  • 11/16″
  • 23/32″
  • 3/4″
  • 13/16″
  • 7/8″
  • 15/16″
  • 1″

If you are torn between two sizes, or the edges are worn, take photos with a ruler in the shot instead of guessing.

Photos to take

  • Width view: housing on its long edge with a ruler across the narrow side you measured
  • Top view: straight down so tabs and mounting holes are visible
  • Back or end view: show lips, hooks, and edge shape
  • Wheel view: one photo of the wheel side (single vs tandem)