What is a drop sill?

How does a drop sill work?

A sill consists of an additional aluminium strip at the bottom of the door. It contains a spring mechanism with a sealing strip made of rubber or silicone. As soon as the door closes, a small pin presses against the frame. This causes the strip to slide down and close the gap between the door and the floor. 

When the door is opened, the strip automatically springs back into the profile. This keeps the door moving freely and prevents the seal from dragging on the floor.

Advantages of a drop sill

A drop sill ensures that there are no gaps under the door. This immediately provides more comfort in the home or office. Draughts and cold are kept out, keeping rooms at a better temperature. 

Because the system is concealed invisibly in the door and automatically springs up when opening, the drop sill is not in the way when you open or close the door.

This is how a drop sill is used

A door should always fit properly to prevent heat loss. Many doors often leave a small gap open at the bottom to prevent friction. However, that gap, among other things, causes heat loss. 

A lintel prevents the door from dragging: the strip only lowers as soon as the door closes, leaving no permanent gap. This keeps a aluminium door of Aluwdoors opens and closes smoothly while still completely sealing the door. So you won't be bothered by draughts either.

Installation and maintenance

A drop sill is integrated into the underside of the door during installation and adjusted so that the strip connects smoothly and completely to the floor. The system is durably designed and typically lasts as long as the door itself. Maintenance on trap doors is minimal. Keep the rubber seal clean by occasionally removing dust and dirt with a cloth.

Alternatives to a drop sill

The drop sill is often used when you want to completely seal off a room. Think of a meeting room, where you want to block out draughts and noise.

Want to know which option is most suitable in your situation? Drop by in one of our showrooms. These are located in Nunspeet, Veghel, Mijdrecht or Barendrecht. Otherwise, take direct contact us on for personal advice.