At Aspire Bifolds we offer eight different bifolding door brands, yet these share many common names and descriptions. A bifolding door is a complex product with advanced engineering and design, giving you large span doors that effortlessly slide and fold. We have created a simple bifolding doors glossary of terms.

Bifolding doors Glossary of Terms.
If you are thinking about having a new bifolding door, you may come across terms and descriptions you are not familiar with. We explain what these mean to help you understand bifolding doors better.
Bifolding door names.
Bifolding door is the most common term to describe a series of door panels that open and fold there are other names used. Concertina doors, accordion doors, slide and fold doors, slide and turn doors and folding doors are all common names used to describe them.
Bifolding door configuration.
The bifolding door configuration refers to how your door is designed and the number of panels. The configuration of your doors also applies to the sliding direction, whether they open in or out and the opening arrangement of one or more leaves.
Bifolding door sight lines.
If you are thinking about visible aluminium you get with bifolding doors, this is known as the sight line. The sight line applies to the door profile visible when the doors meet in the middle as well as at the head, the threshold and the sides of the door.
Our range of bifolding doors includes the latest slimline Visofold 6000 door that is one of the slimmest you can buy today. All our doors offer narrow sight lines to maximise the light and views to the outside.
Bifolding door outer frame.
The bifolding door outer frame you will see fixed to your structure on the one side and is also where the door panels are held in place. The outer frame determines whether your doors open in our out as well. On the outer frame, you will find the locking keeps, door hinges and other components. Outer frames also hold the seals and gaskets than enabling closed doors to be very weather resistant.
Bifolding door jambs.
The jamb on your bifolding door is the correct expression for the vertical sides of your frame, left and right. Some of our doors such as Origin bifolds with a 20 year guarantee, offer a fixed jamb; our Schuco doors offer a moveable, adjustable frame jamb. There is no better method, just the different design features found in individual bifolding doors.
Bifolding door threshold and cill.
The threshold or cill found on a bifolding door is on the base fixed to your floor. Within the threshold, you will find the rollers, carriages and other weight-bearing components.
Under your threshold, you will find an aluminium extrusion called a cill. This is designed to move the water away from the door and to the outside. Whether your door needs a cill or not depends on the individual site survey carried out with every property as no two doors are the same.
Polyester powder coating.
Aluminium bifolding doors are available in over 200 different colours thanks to the benefits of polyester powder coating.
Also known as ‘powder coated’, this is a dry powder applied to the aluminium profile at the same time as an electrical charge is passed through it. Upon application, the aluminium sections are baked in a special oven to cure the paint and give it an extended lifespan.
Powder coating has been used in the colouring and finishing of aluminium for over forty years and has proven its dependability with a huge colour choice. It is the best way to paint a bifolding door.
Bifolding door seals.
Study any door, and you will see rubber, wool or other materials designed to provide a tight air and water seal. Seals are found on the outer frame, the door jambs and the door leaves, depending on the product and how it is designed to resist the weather.
Polyamide Thermal break.
The polyamide thermal break is an insulator inserted between the inside and the outside of all your door profiles to insulate them and bridge the cold. Bare aluminium is not a good conductor of heat and cold. Polyamide thermal breaks are now used in all modern folding doors to give aluminium excellent energy efficiency and thermal performance. The polyamide thermal break has also enabled aluminium doors to come with different colours inside and out.
It is typical for the thermal break to be black, although sometimes this can be painted over. The thermal break is only visible as you look at the frame or door sash with an open door. You cannot see it when the doors are closed.
Traffic Door.
The traffic door is one of the things you will need to consider when deciding on your bifolding door configuration. A traffic door works just like a regular door being independent or part of the folding panels.
The advantage of the traffic door on a bifold is that it enables you to use your doors all year round without having to fold all the panels back. A bifolding traffic door is ideal for letting pets out, taking the washing out to dry, for ventilation or using your bifolding doors all year round.
Slave door leaves.
In a door with a traffic door, the remaining doors are referred to as slave door leaves. Some people may refer to them as intermediate leaves.
Bifolding or carriage.
The bifolding door carriage contains the wheels that sit within the bifolding door threshold enabling the smooth sliding action. Some carriages carry four or six wheels. Some systems have the carriage visible; others conceal it. There is no best method as long as the weight of the bifolding doors is always at the bottom.
Slave leaf Shoot bolts.
A bifolding door contains a master door leaf housing the highly secure multi point lock and lever handle. The remaining leaves also need to lock, and these are fitted with a shoot bolt lock. The shoot bolt is operated by a rotating slim handle that engages secure rods in the head and threshold. This gives consistent locking points throughout the door set.
Bifolding door slave handle.
To pull the doors closed and operate the slave leaf shoot bolt, a D-Handle or pull handle is provided. With one hand you hold the slave leaf tight to the frame and with the other, you engage the shoot bolt.
Our Ewell Showroom showcases some of the latest bifolding doors available on the market today. Contact us or pop in and see us and let us demonstrate our bifolding doors glossary of terms and other features found in quality bifolding doors.