I am now trying to ensure my builder does exactly what I believe he should be doing. He's currently putting up the inner layer of fire board, green glued to the first layer.
The door (there's no window) and the ventilation are the next things which will be tackled. I would really appreciate all help and advice!
Regarding the door - or doors. The inner one is a heavy fire door. The frame has been built and is part of my inner leaf, decoupled from the outer. I've just ordered some rubber seal to go around the frame on all sides. It's 9mm x 5.5mm EPDM Rubber Draught Excluder which my builder has said will do the job - photo here:https://imgur.com/Ag0QqdV
There will be a heavy duty door closure to close the inner door back on itself. The door itself doesn't have a bolt or latch. I appreciate some people use pressure clasps to push the door tight to the seals, but I have also read that these aren't a good idea as it means that access from the outside could be a problem in the event of an emergency.
Can anyone recommend how I can push this door tight without obstructing emergency access from the outside?
Then there's the issue of covering gaps (sides, top and bottom) between this inner door and the solid composite door that's going on the outside leaf. This door comes with its own frame and airtight seals.
I have seen one method where a studio builder used expanding foam to hold strips of wood to the inner leaf only (with insulation behind) and then caulked the small gap from this piece of wood to the outer frame, so avoiding any direct contact from inner to outer leaf. I thought this would work for me so was going to order some of this foam.. Will this foam do the job at this point? (Everywhere else acoustic caulk has been used to fill joins and gaps.)https://www.screwfix.com/p/soudal-geniu ... _container
Can anyone suggest any other method of closing these gaps?