On 19 Oct, 19:20, andrew wrote:
sm_jamieson wrote:
Question: Is it *worth cutting out a 25mm channel and adding permeter
insulation, or is it not worth it now ?
Floor will be tiled and no underfloor heating.

Question 2: Isn't one of the functions of the perimeter insulation to allow
for the relative expansion of the underfloor concrete slab?

AJH

Yes, and is vital with underfloor heating, but there are loads of
solid floors out there before they ever used perimeter insulation, so
it must be OK for an unheated floor which undergoes far less
temperature changes.
I've actually got some air gap there anyway, since in some areas the
vertical part of the DPM was slightly saggy and I didn't jam the
screed up that hard against the side.
Simon.