We had friends visiting this weekend so there wasn't too much time available. They were not arriving until the early evening so I was able to get the door frame glued up. This was glued, assembled then strapped together tightly and left overnight. Later on Sunday after our friends had left I added some screws to the already solidly glued frame. I now have a sturdy door frame to insert into my stud wall. >>photo<<
Following on from an earlier point I have been looking at the available space inside my 'airlock'. It's going to be a little tight to get the computer in the space to one side of the door, at least with the door frame mounted centrally - ie. in-line with the outer door. So the plan is to mount the internal door off-set to one side, probably to the left of the outer door. This may seem a bit odd but what it does do provide a much larger area to the right to locate the computer. I have tested this out in terms of how practical this is for entering the room and it seems to be a very workable idea. A little more thinking to do here but so far I can't see any pitfalls.