Installing a garage door is a precise operation, and one wrong measurement can throw off your entire installation. It is important to know how to do it properly and accurately in order to avoid mistakes and the wasted expense of buying a system that won’t fit. In this article, we’ll take you step by step through the process of measuring your rough opening and clue you in on some things you need to be aware of before you continue with your professional installation.

A few things to know before you begin: 

When taking the measurements of a garage door, you should always measure along the finished rough opening, never the garage door itself. Doing so will give you an improper fit, and will complicate the installation process. It is also important to measure the width and height at their widest and tallest point. Be mindful too of any devices located beside your garage door. They could have an impact on the size and type of the opening mechanism needed for your door to properly function. Such devices could include things like a water heater or an electrical box.

Similarly, Irregular shaped walls or ceiling storage brackets should be reported to the installer before their visit. 

Finally, if you have more than one garage door, make sure to measure each one individually. Even though the rough openings may seem similar at a glance, there may be small differences that affect their fit.

How to take the measurements of your garage door opening

Start by opening your garage door all the way before you take your measurements. It’s a good idea to have someone with you to take notes. Make sure to have a tape measure, a pencil or pen, a pad of paper or some other means of taking down measurements.

Step 1: Measure the exact width of your opening. 

Measurements should be taken at the widest part of the frame, and should be recorded in feet and inches for the most accurate fit as this is how all garage doors are sized. It is recommended that you Use a 25’ tape measure to make sure that you get an accurate measurement without having to stop along the way, make marks, and continue.

Step 2: Measure the exact height of the opening. 

Take this measurement in the center from the finished floor to the inside of the top frame. For accuracy and to check if it’s level, also take several measurements on the left and right of center.

Step 3: Measure the headroom.

Measure the ceiling clearance from the finished floor to the lowest part of the  ceiling or to the joists. Then to determine your headroom, measure the space between the top frame of the door opening and the lowest part of the ceiling or joist. If you are installing a garage door opener you will need a minimum headroom of 12”. Also,  If door height extends above the opening the headroom measurement should be adjusted proportionately. Take note too of any obstructions near the door, such as light fixtures.

Step 4: Measuring the sideroom. 

On the inside of your garage, measure the clearance between the sides of the opening and the cross wall. If you have multiple doors side by side, measure between door openings. If there is a column or other obstacle between two openings, measure from the opening of each door to the obstacle.  Each side of the opening should have a clearance of at least 4″ for a 2″ track, and 6″ for a 3″ track. 

If there is an access door next to the opening of your garage door, then measure the height of the access door and the distance between the opening and the wall beside the access door.

If your garage has multiple openings side by side, like a repair shop for example, then measure the distance between the doors and the distance on each side to the left and right walls. 

Clearances that are too narrow will make installation of your garage door track way more complex. It is important to take the side measurements properly and accurately before speaking to the installer. 

Step 5: Measuring the backroom. 

Time to measure the unobstructed depth of your garage ceiling. The goal here is to find out how much space there is to install the trach that your door will be mounted on. To do this you need to measure from the garage door opening to the back end of the garage wall. This should be done along the ceiling and flush with the wall. If your garage has a sloping ceiling, you will have to find the degree of the slope. To do this, establish a horizontal reference point and base your calculations on the height differences from that line. First, measure the distance from the reference line to the ceiling at the location that is the closest to the rough opening, and then between the reference line and the highest point of the ceiling slope. Be sure to take these measurements on the unobstructed depth of your garage ceiling. These measurements will give the installer the ability to calculate the slope.

Repeat all these steps for each opening if you have multiple doors.

Additional things your installer should be told

You’ve taken all the necessary measurements that your installer is going to need. But there are a few other things that your installer should be made aware of.

If you are purchasing an automatic door, you should verify if there is an existing electrical outlet for door opener use. If there is not an existing one then the installer will need to put one in. you also should let your installer know what type of material they will be installing the track on. 

Conclusion

Commercial garage door installation is a complex operation. Proper measurements are needed to ensure accuracy and safety when having a new commercial garage door installed. Following the steps above, you can ensure that your new garage door fits your commercial space before your professional installer arrives.

In the market for a new commercial garage door? Contact Connecticut Garage Door Service today!