Publish Time: 2021-04-27 Origin: D&D Hardware
Rising butt hinges are designed to allow doors to close slowly using gravity and lift the door slightly as it is opened.
When to use rising butt hinge?
1, Where a door closer is not required but where it is desirable not to have the door resting wide open, such as, bathroom / toilet cubicles doors.
2,Rising butt hinges also design allows doors to open and rise up on the hinge to clear the thickness of your carpets.
If you’ve just had a new carpet fitted, and it can be frustrating to discover that your internal door doesn’t close quite so easily due to the thickness of the new carpet. In this case, you might be thinking of shorten the door to fit the carpet. However, there is a cheap and easy way: using rising butt hinge instead of a standard hinge to your door, it allows the door to rise slightly when opened.
To enable the door to function properly, it is necessary to ease the top edge of the door sufficiently to allow for the rise of the butt.
When not to use rising butt hinge?
In the Code of Practice the use of rising butt hinge is discouraged from the fire resistance viewpoint for the following reasons:
a) When the door is returned to its closed position, this means that a gap in excess of 9 mm will exist at the head of the door. This will be in addition to the 3 mm gap, which is the recommended maximum for fire doors, making a total of 12 mm where the thickness of the door stop is only 12mm. The head of the door is the most vulnerable point of the door if a fire breaks out. It is at this point that the pressure of smoke and hot gases, searching for cracks and fissures through which to escape, is highest.
b) The closing force exerted by rising butt hinges is extremely low and will not overcome air pressure differences or resistance from latches, seals or carpets that might be fitted, and therefore they cannot be considered as reliable door closing devices.
These hinges do not meet the requirements in Approved Document B 2006 edition for self-closing devices. Rising butt hinges contain a ramped profile between the two hinge blades which causes the door leaf to rise as it is being opened. The mass of the door leaf will then tend to close the door when it is released. To enable the door to function properly, it is necessary to ease the top edge of the door sufficiently to allow for the rise of the butt. When the door is returned to its closed position, this means that a gap will exist at the vulnerable head of the door, which could compromise the fire integrity of the door assembly.
In order to achieve any form of self-closing, the butt hinges must be accurately aligned. Additionally, to meet the recommendations of BS 4787, there is a requirement for 3 hinges per leaf whereas rising butt hinges are traditionally fitted as 2 hinges per leaf, while fire tests are also carried out with 3 hinges per leaf. Correct alignment is extremely difficult to achieve with 3 hinges.
The closing force exerted by such a device is extremely low and will not overcome air pressure differences or resistance from latches, seals or carpets that might be fitted, and therefore they cannot be considered as reliable door closing devices. Whilst such devices are still permitted in dwellings and flats covered by Approved Document B (2000 edition) for certain domestic applications only, they are NOT recommended for any fire door application by the Code of Practice.
Only the right one can make the best use of the product. It's the same with hinges. Different weight, different types of doors should choose different hinges. The proper hinge can not only fully play the role of the door, but also extend its service life and reduce the increase of later cost. D & D's stainless steel hinges have passed strict safety tests (including BS, en, CE, UL, ANSI and BHMA) and are suitable for education, health care, hospitality, residential and commercial applications
Lots of different hinges are available at D&D, consultant with D&D specialist for your special need.Click here.
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