Can I use rising butt hinges as a closer for my fire door?
Approved Document B cites rising butt hinges as acceptable for use on fire resisting doorsets, providing there is suitable test evidence available. To the best of our knowledge, there is no supporting fire test data for the use of rising butt hinges and this, coupled with their known limitations, lead us to recommend that such hinges are not used with fire resisting doorsets.
In order for rising butt hinges to operate effectively, either the leaf head or frame head has to be chamfered, which means there will be the correct leaf to frame gap on one side of the door, but too large a gap on the other. If the gap is too large, the intumescent seal will not react as intended and it may therefore negate the performance of the leaf.
In some instances both the leaf and frame head may be simultaneously chamfered, giving rise to a different but potentially serious problem whereby the reacting intumescent seals in the head force the leaf open due to the direction of flow and pressure from the reacting material.
Another problem with rising butt hinges is that they rely on gravity to close the door over the latch and it is quite common for pressure differentials within a building to prevent the hinges from doing so. This can then lead to the door ‘bouncing’ on its latch and not fully closing within its frame reveal, thus failing to function as an effective fire resisting doorset.
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