FAQs

Garage Door Measurement

• Measure existing door width and height in feet and inches. This determines the size of door needed. The rough opening should be the same size as the door.

Write down the following measurements:

1. Width
2. Height

• Measure for side room: 3-3/4" is required on each side for installation of the vertical track for standard extension or torsion springs.

Write down the following measurements:

1. Left Side room 
2. Right Side room

• Measure area labeled "headroom"—distance between the top of the door opening ("jamb header") and the ceiling (or floor joist). 10" is required for standard installation of extension springs, 12" on standard torsion springs.  14" of headroom required for Carriage House doors. If you have restricted headroom, special hardware is available. Low headroom hardware is available to reduce requirement to as low as 4-1/2".  Note: If door height extends above the opening, the headroom measurement should be adjusted accordingly.

Write down the following measurements:

1. Existing Headroom
2. Headroom Needed

• Measure area labeled "backroom." Distance is measured from the garage door opening toward the back wall of the garage.

Write down the following measurements:

1. Backroom 

Common garage door sizes include 8' wide x 7' high, 9' wide x 7' high and 16' wide x 7' high. JB Mathews Company can provide most doors in nearly any size you require.