Fire Doors replacement

[mariner]

We are having some fire doors replaced and I understand that the framework as well as the doors should be replaced at the same time, however on inspection the frame work appears to be softwood with hardwood doors, what BS mentions fire door design
 

[nearlythere]

what BS mentions fire door design

None. The BS is a test. You can make what you consider to be a fire door and to prove it you would get it tested and if it passes the test you will get your particular design certified.
Doors are usually tested as a set - door and frame - but it is a bit OTT to change a frame when the existing may already be suitable and adequate.
There is guidance floating about cyberspace on frame design and dimensions. I will have a look and give you a link.

[kurnal]

You can dowmload excellent free guidance on fire doors here:

http://www.asdma.com/bpg.html

BS8214 covers fire doors.

[mariner]

Thank-you for the excellent link and comments much appreciated.

[Fishy]

Not used this myself, but I’ve been told by colleagues that if you take a sample (e.g. a core) from the existing frame, then send it to TRADA (the Timber Research & Development Association), for a small-ish (apparently) fee they’ll be able to tell you the species and density.  If the evidence of fire resistance performance for the doorsets covers that species and density, then you’re laughing...

You can actually measure the density yourself, with a set of reasonably accurate scales.  Helps if the sample isn’t too small, though.