In keeping with the thermal mass concept of a passive solar house, we are tiling most (if not all) of our floors. As I posted earlier, we have finally come up with a floor design for the living/dining area and those are on order.
We had planned on doing some acid etching, but just haven't been able to get motivated for that. Still an option for the bedrooms though. The trials are in working with rough concrete floors.
David has even had to do some grinding on one larger "bump". If you think wallboard sanding makes a mess, try sanding concrete in your living room! He has also used a "primer" layer of thin-set to help even out the base.
He says he is learning quickly all about tile - probably more than he has ever wanted to know.
The furnace still hasn't kicked on, but Wednesday is forecast to stay in the teens during the day and dip near zero at night. I am afraid we may break the stretch then. Still burning the Tulikivi only once a day though - and still loving it.