On 2007-05-30 13:22:54 +0100, The Natural Philosopher said:

robgraham wrote:
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

Use duct tape to seal and mask and then inject foam.

It that doesn't stick you have a bit of a problem.

This does work (I've done it), but it's a good idea to spray the area
first with water e.g. from a plant sprayer and to inject the foam a
little at a time. Since it expands and cures in the presence of
moisture, one can get a better idea of how much expansion will take
place sooner. Otherwise, it can go on expanding for several hours if
the surfaces and the air are dry - not a problem this week :-) This
application isn't to fix anything or to be particularly structural so
it's possible to put in foam a little at a time.

With over enthusiasm, it is easily possible to have Peter Parry's
Sorceror's Apprentice canoe syndrome and expnading foam is more than
able to lift duct tape from a surface.

The other thing is that PU foam does tend to deteriorate in sunlight so
a good idea to cover the exterior somehow.