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.
