Screw size for fire door hinges

[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.

[Collegeboy]

It wasnt actually worrying about the difference in size or how hot the fire may get, but fact is, When a door is given its certification, that certificate is issued under condition that when the door is fitted the parts used are as per stated, if you pick ANY bwf CF from the top rail of a fire door, or a BM Trada plug and get the certification, they all state Minimum No8 screw, with deviation in thickness/length if there`s a different core, I  have yet to see ANY CF allowing a No6, as an example, attached is a shot of a CF Installation instruction that is used for PROPER fitting of a Door, Note the instruction for No8 Screws    so I was just wondering if anybody advised upgrading from 6 to 8 as a new door with No6 screws holding the hinge would void certification   

[Dinnertime Dave]

The problem is, the vast majority of Fire Door Inspection companies and inspectors don't apply a risk based life safety approach

Agreed, I have seen issues raised on kitchen doors on theatre style kitchens. Surely, someone noticed the big hole in the wall next to the door.