Top or Bottom Tracks on Bi-fold Doors - What's the Difference?

It's a regular question asked when looking at bi-folding doors, and different suppliers will offer different opinions. So what should you opt for? 

Some suppliers will only offer one or the other largely dependent on their own system’s capabilities and you'll often find that they state that their system will be suitable for the project as a result. However this isn’t necessarily the case and it’s a good idea to base the choice of product and therefore supplier on the structure of the property using the following concept.

As standard bottom running tracks are recommended for standard heights (ie up to 2350mm) as they do not require such structural support at the top of the opening. The plus with this is that this option tends to work out cheaper. They can also have slimmer head profiles than a top hung system so a little more aesthetically pleasing as won't require additional bulk in the frame.

Top hung however is usually recommended when doors are needed to be much taller ie up to 3000mm, or if the system is heavier, for example, if the system has triple glazing further structural considerations will come into play. With such heavier weights, top hung systems will also help to prevent the door weight de-railing the systems. To protect against this a good quality system will offer sprung running gear guides to ensure wheels stay in contact with the track. 

Bi-folding doors are often used to open out large areas so it's really important to choose the best system for your individual project. You don't want to be faced with issues further down the line.