FIRE SERVICE AND GENERAL FIRE SAFETY TOPICS > Fire related queries from non specialists

Screw size for fire door hinges

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Collegeboy:
Hi lovely people
if an old fire door has steel hinges (unmarked) and No 6 screws, should the screws be upgraded to minimum No8 / 32mm  ??? or is it not required and the No6s can stay, obviously its old doors with no certification / plugs / labels
thanks
Bill

Dinnertime Dave:
What increase in performance will changing the screws give you?

Put simply, How big and how hot does a fire have to be to affect the performance of the door due to the length of the screws. I would suggest very big and very hot. Therefore, if the fire is very big and very hot the length of the screws is the least of your problems.

Collegeboy:
because the Best Practice Guide states .... Hinge fixings-It is recommended by BHIF that hinge fixing screws should be of minimum size 30mm x 3.8mm (No 8.) in order to obtain the required support for the door leaf and avoid early loss of screwholding due to erosion in a fire.
Also, ASDMA states ... 18.8.7 Hinge fixings The GAI recommends that hinge fixing screws should be of minimum size 30mm x 3.8mm (No. 8.) in order to obtain the required support for the door leaf and avoid early loss of screw holding due to erosion in a fire.

So the larger screw seems to be seen as important in official documents for required support under charring, what Im asking is should older doors with No 6 screws be recommended for upgrade for No 8s for better holding or because they were fitted before new regs / advice, are they alright to stay  ???

Dinnertime Dave:
Forgive me if I?m wrong. The difference between No 6 and a No 8 screw is about 6mm (Google)

Will that make any significant difference to the performance of a door. Take the compliance hat off and look at it from a risk based approach.

I really don?t think you should worry from a life safety perspective.

AnthonyB:
The problem is, the vast majority of Fire Door Inspection companies and inspectors don't apply a risk based life safety approach and will happily expect every door in every building to be 100% to current specification, resulting in massive remedial quotes for clients with even the most apparently trivial things often resulting in requirements to replace whole frames or doors.

Obviously a hollow 'egg crate' door or one with 10mm gaps all around is a big problem but some of the issues you see raised don't seem likely to affect life safety.

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