Hi

I’m installing a bathroom into my basement which has Concrete floor. Property is in  Calgary Alberta (zone6?)

The plan is for heated floor (probably Schluter Ditra heat) with tile. Ceiling height is quite tight so I’m trying to weigh up options for the floor to minimize height loss

Ideally don’t want cold feet, but is it really required if I have the layer of Ditraheat? Or any ideas on the best insulation option which would work with the heated floor and the tile? Ideally don’t want to lose more than an inch. 

Secondly there is old vinyl on the concrete floor. Any issues with just leaving that in place under the ditraheat? It is glued very securely. 

Regards

paul