Measuring for Sectional Garage Doors

Sectional garage doors are some of the most popular that we offer. CDC Garage Doors have supplied and installed sectional garage doors from a huge range manufacturers to a wide variety of properties. Practical and stylish, they can be fitted in almost any kind of garage but it’s important that you should know how to measure for them correctly to ensure that your door is perfectly designed. If you have any questions about sectional doors or specifics on how to measure for them please give us a call on 0800 294 2002 or email

Usually sectional garage doors are designed to be installed inside the structural opening. This is because this type of door is most often used to maximise the width and height of a smaller opening. However, if it’s more important to maximise length, it is usually best to install the door in-between the opening.

When you are installing inside the opening

Installing inside the structural opening makes best use of the drive through dimensions of your garage opening. So if you have a smaller structural opening it’s usually best to do it this way. To measure you should take the width of the opening and add 90mm on each side. Then for the height you should take the full height of the opening as well as an additional measure that differs by manufacturer – please be sure to contact us regarding this to ensure you’re using the right measurement. It’s also important to measure the inside face on either side of the opening, the headroom and the depth of the garage itself.

When you are installing in-between the opening

Please remember that sectional doors always have a sub-frame, so it’s important that you shouldn’t simply use the measurements of the opening for your door. The manufacturer will need to take into account the size of the sub-frame. Measure the width, height and the depth of the garage in several places, using the smallest measurements.