New hinged doors with fiberglass insert let light into the rooms – but the previous hold-open no longer works with them
Previous form of hold-open only possible with the old, solid wooden doors
Hinged doors that open outwards are perfect targets for the wind. The employees of the Freiburg highway maintenance authority had to learn this from experience. Before the renovation, they solved the problem with simple hooks.
However, this type of hold-open also had its disadvantages:
- if the wind pushed the doors in the opening direction, the hooks were easily bent
- if the wind pushed the doors in the closing direction, the fastening to the wall and door had to be extremely stable so that it would not tear out.
So a solution had to be found to meet the requirements on site with the new, modern doors after the refurbishment.
Wanted: Possibility to hold the doors open without a tripping hazard on the floor
The company Held from Freiburg im Breisgau was commissioned to supply the new doors. Their translucent fiberglass design allows light to penetrate into the rooms behind. But the previous form of hold-open was no longer possible.
What were the requirements for the doors’ hold-open?
- The doors should not slam open while opening, even under high wind loads.
- They should normally remain in open position all day.
- No hold-open devices could be installed on the floor, as these would be a tripping hazard.
- The doors had to be secured against being pushed shut by the wind.
An overhead door closer with a hold-open device would not have been able to meet these requirements, especially under higher wind loads, and was therefore ruled out from the start.
The original solution: simple and very inexpensive – but could no longer work with contemporary door standards: the doors were simply held open with hooks.
The new doors equipped with a back check and door holder for double safety, so that they cannot be pushed shut by wind.
They were able to solve all 4 requirements with the help of DICTATOR
- A back check with a stroke of 400 mm and integrated hold-open was used to prevent the door from slamming open and to hold it in the open position. It is attached to the solid frame of the door and is designed for an opening angle of 90°. The hold-open does not have to be released for closing. It is enough to simply pull the door closed using the door handle.
- As an additional safety measure to prevent the doors from closing under high wind loads, a door holder ZE was installed on the doors. These only have to be actuated in the event of higher wind loads. The door stops are extremely resilient and robust, as the housing is made entirely of cast aluminum. In this case, a stroke of 60 or 75 mm was enough to compensate for the height difference between the bottom edge of the door and the floor. However, DICTATOR also supplies door stops with a height difference of up to 200 mm.
Of course, the exact installation positions for the back checks were calculated by DICTATOR, so that the installation could be as smooth and fast as possible.
Door with back check with integrated hold-open and additional door holder – as double safety, so that the door is not pushed shut in strong winds. The door shouldn’t open more than 90° because of the service station area behind it.
The back check is attached to the top of the door frame and door with mounting brackets – supplied by DICTATOR. The fixing points have been calculated by DICTATOR especially for this application – for a quick and easy installation.
Normally, the door holder is not used, as the integrated hold-open function of the back check is enough. But in the event of higher wind loads, it is used as a double safety device to prevent the doors from being pushed shut.
Normally, the doors are open all day. The back checks ensure that they do not open more than 90° and are slowed down before they reach the open position (which protects the door and its hardware).
Products used
Back checks
Back checks are used on doors or windows that can be blown open by wind, draft or even during normal operation. They dampen doors/windows in the opening direction and limit the opening angle. This prevents doors and windows from swinging open without control, prevents damage and protects people standing next to the door. Various models cover a wide range of applications: from lightweight interior doors and windows to very large/heavy doors with high loads. Many models can be used in combination with overhead door closers and are optionally available with an integrated hold-open in the open position.
Door holders
Hold doors in any position – small size despite stroke lengths of up to 200 mm. Ideal for use outdoors or in damp environments as they are made entirely of stainless material.
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