On Jul 24, 8:49 pm, Andy Dingley wrote:
I'd suggest attaching a "sub-batten" alongside the wall battens and
stapling the foil down to those.

How about if I staple the foil "half-way down" the thickness of the
batten, i.e.:

Instead of:

-------------------------------------- Foil
##############
##############
##############
### ###
### Batten ###
### ###
##############
###################################### Wood


I do:

+----------------+ Foil
| ############## |
| ############## |
| ############## |
--------+ ### ### +-----------
### Batten ###
### ###
##############
###################################### Wood

The foil would be pulling at right angles to the staples. Is it likely
to tear?

(That diagram might look funny in a newsreader)