Something's got a bit lost in translation here Tony. I'm afraid I can't follow what the "strip" is that you refer to. No matter ...............
Usual rules .............. a 30 minute fire should should be provided between a dwelling and its garage. Now, whether a conservatory counts? I assume it would.
So ....... 30 min self-closing door ............ fitted with intumescent strips along the top edge and both sides,........... plus, usually, thicker door stops (timber fire-stops).
Also ......... to allow for fuel spills, the garage floor would be laid to fall away from the conservatory towards the garage car entrance (presumably at the front).
Since the floor is already in place, the alternative is to have a 100mm threshold under the fire door into the conservatory.
This is to contain any fuel spills, and give you something to trip over ;o)