Are there any issues related to using rising butt hinges as a closer for my fire door?
Fisrtly, although Approved Document B suggests that rising butt hinges are acceptable for fire resisting doorsets it would appear there is no suitable test evidence available for these hinges as far as we are aware, coupled with their known limitations we are unable to reccommend them.
The main issue with rising butt hinges is the ceratinty that the head of the door must be chamfered to allow the door to begin rising, this in itself leads to the clearance between the door and the frame head being too large and therefore compromises the effectiveness of the intumescent seals
We are aware that the top edge of the door and the frame head could both be chamfered in such a way as to maintain an equal clearance, the problem in so doing is that the intumescent seal could portentially force the door to open during the expansion process that the seal goes through when subjected to heat and pressure.
Lastly, rising butt hinges close with gravity but this is inconsistent and is therefore not suitable to absolutely guarantee safe closing of the door on to the latch or indeed remain closed on the door stops when building pressures are brought in to the equation, inconsistency is not permissable under test conditions, these rising butt hinges are therefore unsuitable for fire door sets or fire doors fitted on their own.