[Gaps]

When a  fire door has been fitted occasionally they do not close exactly flush to the door stop.
May be warped
Twisted
Poorly fitted
Water damage
Structural movement
And other possibilities.
I know its 2-4mm max between leaf and. Frame but What is the maximum acceptable  gap size between the header and the latching side of the door leaf? 
Cheers 
 

[Strike plate bolt latch rebates]

Thank you Neil

 

[Strike plate bolt latch rebates]

On 19/09/2024 at 20:17, AnthonyB said:

Dust Box?????

 

 

[Roller bolt bolt nigh latch on nominal fire doors]

7 hours ago, Neil Ashdown MAFDI said:

Roller bolt type latches are not usually fitted to fire doors. Section 6 of the document 'Code of Practice: Hardware for Fire & Escape Doors' deals with latches and the many fire door related issues concerned with the different types.  The document is available online at http://firecode.org.uk/Code_of_Practice_hardware_for_fire_and_escape_doors.pdf

Below is particular commentary on Roller Bolt Latches

Fantastic just what i needed. ive identified the item as a yale 81 rollerbolt nightlatch

[Roller bolt bolt nigh latch on nominal fire doors]

I understand it  a latch bolt must overcome the strike plate, stay in position (positive latching) and opened manually from the inside with a lever/handle and outside with a key or code etc.

My concern is that the roller bolt does not automatically lock into position and can move freely.

Theres no unlatched test evidence for the door but if the self closing device is able to keep the door closed against the frame is it acceptable? 

[Strike plate bolt latch rebates]

Are dust boxes on flat entry fire doors required on strike plates when rough timber rebates are  exposed. Particularly nomunal doors