drhex wrote:
Is the existing screed insulated towards whatever is underneath? You‘ll be heating your basement or mother earth otherwise (don‘t ask, how I know...).
There is that. Way back when we built the house I asked the builder about insulation under the slab but asked too late for him to have any interest in doing it, so no insulation. At the time is was destined to be the shop so no big deal but now it would be quite helpful.
Now, the best thing to do is remove the slab and start over...so around $10k plus the insulation and pipe cost. Second best is probably the something like the Roth panels
http://www.roth-america.com/products_radiant_panelsystem.cfmThey say floor directly over and only adds 3/4".... but its foam...so not convinced it will hold Lana's pool table without some plywood which add thickness ...probably 1.5" by the time its good.... hate to give up that much height.
Anyway my thought of the day is the basement is not hot right now with 90 degree summer weather so geo cooling is not all bad. Then come winter I was thinking run the floor to a relatively low max temp....70-75 maybe so its not COLD, but not hot enough to lose a lot of heat and let the geo forced air system I just ran ducts for actually control the room temp when more heat is needed....or put Lana in charge and we'll have 80-85F floors leaking buckets of heat to the ground with the AC running all winter to keep the room cool enough