Looking at getting late 1880`s 4 storey tenement re-slated, exposed
position , scotch slates are slipping towards gutter at increasing
rate, lead work evaporating etc. Flat platform in middle recovered 4
years ago.

Seem to have decided on Spanish slate as against reclaimed Scotch on
balance of cost and apperance, some areas would have to be Scotch, not
here.

Seems to be varying opinions on covering bleow new slates though, some
say use a breathable fabric and no additional slate vents, others
appear to be advsing non breathable and ` a few ` slate vents.

Seen loft to habitable conversions and BC seem very keen on lots of
slate vents. Whole of this roof is above habitated space.

Whats anyones experience of undertile fabrics and the pros and cons?

Thanks
Adam