Here are some of the common terms we use when talking about our bi-fold doors and windows. Some terms are only applicable to our doors, others apply to both our windows and doors. If you're unsure what a term means hopefully you will find an explanation below. If you require further help then call, fax or e-mail us.
Direct Fix
A style or type of extrusion that when installed can be fitted directly to the brickwork without using a sub-frame.
Cill horns
A projection cill which is wider than the opening is said to have cill horns. The amount of extra door/ window cill each end can be varied. If chosen the horns normally extend 25mm or 50mm.
Low threshold
The threshold is the bottom of the door which you step over as you go in and out of the door. A low threshold is not as high as a standard threshold - making access easier. Weather performance is reduced when compared to a standard threshold - but is ideal for internal applications between rooms or possibly external applications in sheltered areas.
Standard threshold (Folding Door)
The threshold is the bottom of the door which you step over as you go in and out of the door. A standard threshold offers the best weather performance - but is higher overall than the low threshold.
Standard threshold (Folding Window)
The threshold is the bottom part of the window frame. We recommend our standard threshold on our windows as it offers the best weather performance.
Face drainage
A slot in the outer-frame to allow excess water to drain out from the outer-frame. The slot is covered by caps to hide the hole.
Floating mullions
The part of the door / window system which sits between each door sash. It incorporates the shoot-bolt locking, track rollers and head rail guides. The sashes are hung on these mullions.
Traffic door
A door that can be used like a standard hinged door without having to fold the other panels to use it. With a traffic door you can enter the room from outside. Without a traffic door you cannot enter the room from outside.
Brook-vents
A ventilation system to allow fresh air into the room whilst keeping the doors closed/locked to maintain higher air quality. Brook-vents sit between the top of the sealed unit and the door sash. Traditional 'trickle vents' are fitted in the outer-frame to achieve the same result - but traditional trickle vents cannot be fitted to our bi-fold doors.
RAL / KL colours
A paint and printing industry standard way of referring to different colours. You choose a RAL / BS colour reference from a colour chart. You can specify a gloss level of your paint too. The gloss level options are Gloss, Semi-Gloss and Matt.
Shoot-bolts
Part of the locking system which is fitted to the doors. Shoot-bolts are rods which slide up and down from the door sash into the frame - securing both the top and bottom of the door.
Polyamide
Also known as polyamide thermal break. Part of the aluminium extrusion which thermally separates the front and the back of the aluminium - thus keeping the cold outside aluminium physically away from the aluminium on the inside of the door.
Finger safe gasket
Gasket located around the outer-frame, panels and floating mullions, designed to stop fingers being crushed when closing the doors.