In blocks of flats that have a
‘narrow cavity’ (40mm) wall
to the un-heated corridor,
can the ‘narrow cavity’ to the
UHC be filled with expanded
polystyrene beads to satisfy
PAS2035 and be signed
off as compliant or can the
narrow cavity be insulated
with EWI directly? Will the
UHC be considered a fail if left
uninsulated?