Exteranal fire rated door for atatched garage-extension

[Paul Alan]

I am looking for some help please, I have had a two storey extension and the bottom is split into a utility area and a "garage". It's too small for a car and will only ever be used for storage etc but it's being classed as a garage.

 

The side entrance door to be used for access to the rear garden without going through the house is around 700mm from the neighbours fence, I think thats the reason BC want a fire rated door there.

 

I have looked at PVC but thats very expensive as apparently it needs to be a special composite material, the steel ones are around £500 with delivery so I will most likely fit a wooden lining and door.

 

I called a local supplier and they can supply me with a lining but no certificate as they dont test them, I imagine it will cost more to get a certified one which I think BC will insist on ( Have tried to contact BC but no reply from them as yet )

 

I have been looking around online for how to fit an external door lining and it doesnt look as straight forward as I first thought, It lloks like I may have to account for thermal bridging.

 

Can anyone tell me how I fit an external fire rated door lining please?  Do I need to do more than simply atatch the lining to the wall? I have an insulated cavity closer in place but thats all, it's just an opening in the wall at this point.

 

Any help greatly appreciated!

 

Paul