Bifolding Door Glossary of Terms

A bifolding door has many different elements and parts. If you are currently researching buying new bifolding doors for your home, your local home improvement company may use terminology to explain bifolding doors and their installation you may not be familiar with.

We have put together this glossary of the most common bifolding door terms to help you.

Bifolding door configuration.

The bifolding door configuration is the design of your bifolding door including the number of door panels and how they open, slide and fold.

Bifolding door sight lines.

Sight lines refer to the visible aluminium profile, mainly when the doors are in the closed position. Sight lines on bifolding doors vary according to the system.

Bifolding door outer frame.

The bifolding door outer frame is the perimeter frame fixed to the structure of the property. The outer frame carries the gearing that makes the bifolding door slide, fold and lock. Outer frames can also contain the seals that keep your door weather resistant.

Bifolding door jambs.

Bifolding door jambs are the sides of your door outer frame. Some systems offer adjustable jambs that the installer moves into position to ensure consistent door clearances throughout the bifolding door assembly. The lock jamb is on the locking side of the door and contains the keeps that the multi point locking on bifolding door engages into.

Bifolding door cill and threshold.

The bifolding door threshold is at the base of your bifolding doors. The rollers sit within the threshold enabling the doors to slide. Beneath the threshold is the cill (also sometimes spelt sill). The requirement for a cill depends on the way the bifolding door is being fitted and the individual property.

Polyester powder coating.

Polyester powder coating is the paint finish applied to bifolding doors. Polyester powder coating is a dry paint process. An electrical charge is applied to the aluminium sections and the coloured powder bonds to the aluminium. The aluminium sections are then placed in a special oven to cure the powder and create the final colour. A bifolding door is available in over 150 different colours.

Bifolding door seals.

The seals on a bifolding door are available in EPDM Rubber or a Q-Lon material. You will find bifolding door seals on the outer frame and the door sashes. When the doors close together and meet the frame, the seals compress to provide weather resistance and protection from the ingress of water or rain.

Thermal break.

A modern aluminium bifolding door has a thermal break. This is a polyamide strip to separate the inside and outer frames of the aluminium extrusion. Thermal breaks insulate the aluminium profile and help with the overall energy efficiency of the bifolding door. The thermal break can be painted white or left naturally black. The thermal break is only visible when the doors are open in the same way the locks, hinges and other components are visible.

Bifolding door leaves.

The bifolding door leaves are the door sashes that slide and fold. Depending upon the configuration, bifolding door sashes contain the traffic door and the intermediate or slave door panels.

Traffic Door.

The traffic door is an independent door that operates just like a regular swing door. A traffic door is most useful in a bifold for convenient access in and out without having to fold all the leaves back. Configure your bifolds with a traffic door if the bifolding door is the only external door in your home. Traffic doors are great for taking out the washing or rubbish and letting out pets quickly and easily.

Intermediate or slave door leaves.

In a door with a traffic door, the remaining doors are referred to as intermediate or slave door leaves.

Bifolding door carriage and top guide.

The bifolding door carriage is a component containing up to six wheels that enable the doors to slide within their track. The bifolding door carriage is found at the bottom of the doors in the threshold. The top guide is a similar component at the head of the doors designed to keep the doors in place as they slide.

Shoot bolts and gearbox.

The slave leaves on a bifolding lock with a handle fitted with a gearbox. The gearbox operates the shoot bolts that engage at the top and bottom of the door locking the door in place.

Bifolding door slave handle and D-Handle.

To pull the doors closed, the D-Handle is a round or square handle positioned above the slave handle. As you hold the D-Handle against the door, the slave handle is rotated to activate the shoot bolts.

You can view all these components and terminology in our Letchworth showroom open Monday to Saturday. On display are many different bifolding door sets within real-world installations so you can see clearly how thresholds, frames, doors and sight lines can work in your home. At Open Living we also have a huge selection of colour swatches for aluminium and our range of integral or fabric blinds and door handles. Contact us today to find out more.

01767 448 005