We have all of the fire doors and fire door frames (certified from source) to fit 5 new doors and frames in a mid terraced property to rent.

Does this require specialist installation by a specialist installer?

If not, can we D I Y ?

If diy is permissible, please could you advise how to fill in space either side when gap is up to 2". Door frames and door manufactured to size closest to apeture. Old doors removed. Any help and advice warmly appreciated.

The guidance for fire door installation is BS 8214:2008 Code of practice for fire door assemblies and includes the following note, "Approved Document B of the Building Regulations 2000 [6] recommends that the installation of fire-resisting products be covered by product conformity certification or by independent registered installer schemes, where such schemes are available. Also in the above BS it gives guidance on how to fill the gap between the frame and wall and suggests suitable packing, intumescent material as a preformed strip seal or Mineral or glass wool packed to a depth of at least 10 mm or Intumescent paste, mastic or other suitable material.

For more guidance check out "Guidance on Fire Door Installation" click here