This is the last part of my workshop refurbishment ! The stonework is
undressed so the gap between the framework/weatherboarding and the
stone is up to an inch and has a howling draft coming through it at
the moment.

The solution I see is expanding foam but I'm not sure of the best way
to apply it. Options thought of so far -

1 From the outside but will it get all over the stonework?
2 Put a profiled board down the join on the outside and inject from
the inside, but then the foam will equally ooze onto the stonework as
the profile board won't be that accurate and also the foam will end up
in the profiled sections of the weatherboarding.
3 Pack the outside of the joint with newspaper and inject from the
inside, but then I wouldn't be able to get rid of the newspaper.

Any other suggestions please. I could have profiled the
weatherboarding as I fitted it but rejected that at the time as
unnecessary.

Thanks

Rob