Sapa Aluminium Bi-Folding Doors - Glossary of Terms

Here are some of the common terms we use when talking about our Sapa bi-folding 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 extra each end can be varied.

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
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.

Face drainage
A slot in the outer-frame to allow excessive water to drain out from the outer-frame. The slot is covered by caps to hide the hole.

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. With the Sapa aluminium doors, all designs include a traffic door.

Trickle-vents
A ventilation system to allow fresh air into the room whilst keeping the doors closed/locked to maintain higher air quality. Trickle-vents are fitted in the top of the sashes. One or more leaves can have trickle vents to give the required airflow rate.

RAL / BS colours
A paint and printing industry standard way of referring to different colours. You choose a RAL / BS colour reference from a colour chart.

Hinge-bolts
Part of the locking system which is fitted between the panels. Hinge-bolts are locks which are positioned from one door to the next, this helps to prevent forced entry between the panels.

Flush-bolts
Part of the locking system which is fitted to the panels. Flush-bolts are locks which slide up 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 between the folding panels are designed to stop fingers being crushed when closing the doors.