Thickness for fire door check stops

[Guest Matt]

I'm part of a local charity that has had a number of FD30 doors fitted to existing frames. I'm looking for clarification/guidance on the thickness of the door check stops. At current the carpenter has fitted 19mm thick kiln dried timber. I've seen reference to 25mm stops. I was hoping to find clarification on this subject?

Thank you for your time.

Regards

[AnthonyB]

25mm stops date back to the days before intumescent seals and smoke brushes existed and were a rudimentary way of forming a seal on a door  - if your doors are correctly fitted with intumescent seals (and if on an escape route smoke brushes) the 25mm stop is not required and a 19mm stop should suffice.

[Guest Fire door rebate]

Is a 18 mm Mdf rebate ( slam strip )

sufficient on a new domestic fire door  ? 

or is pine  .this of course sjoupd be glued & pinned / screwed 

 

[Neil ashdown]

The new fire door will come with installation instructions or a technical data sheet. That information document will state door frame and planted stop requirements.

[Guest Alec Jameson]

When would a frame with 25mm door stop need upgrading to include an intumescent strip if the the 25mm was a standard before?

[Neil Ashdown MAFDI]

Where the fire door is so critical to the fire strategy at the building that it is desirable to upgrade the fire performance of the door. Consider that all timber-based fire doors have had intumescent seals for around the past 30 years now.  So why wouldn't you fit them to a fire door?