Bill wrote:

In message , tzd3sw
writes

I'm building a thermalite wall between my garage and what will be a
utility room. This wall will have a door through. What size gap should
I leave for the door and frame ? Is there a standard size ? This will
be a firedoor if it makes any difference.


Many thanks.


I'm not sure about standard sizes but the ones I recently bought are 30"
X 78"
Two points I found when I had a similar situation were.
Firstly the BCO insisted on an automatic door closer, I used one
of the spring loaded chains that fitted into the hinge side of the door.

Secondly it was also necessary to have a step down into the
garage from the utility room so that any fuel spills in the garage could
not flow into the house.


There tends to be a minimum size for doors consistent with getting a
wheelchair through - I think its about 800 mm clear opening. Translates
to about 850 mm actual internal frame size. This from memory on the
'principal storey' (i.e. ground floor). Check the regs, even if you
think its ********, because even in the BCO agrees with you, he has to
enforce the rules..