What type of flooring can go over a radiant concrete slab?
My husband and I just retired and are planning an off-grid (active and passive) solar home on our son's property. I've been very excited about the idea of a single-story, on-slab home with radiant heat.. until I realized that the cement is REALLY hard to fall on. I fell in our garage last winter and fractured my pelvis in 3 places. The last thing I need in my "forever home" (aka "I hope to live here until I die!) is a cement slab. What could I cover it with that is safer for being old? I know it would be less than ideal.... or.... Should we find other ways to get the thermal mass and give up on radiant heat?
There is no need to give up on either thermal mass or radiant heat. The cheapest and most durable surface for a slab would be polished concrete, but there are other flooring options for slab on grade homes. We covered a concrete slab with cork tiles for one of our Ecohome demo houses, cork is renewable and non-toxic, and softer on the feet. You can use engineered wood as well, that will reduce the risk of cupping and warping compared to solid wood floors.
There is of course the issue to consider of how it will slow the heat delivery from your floor, but personally I wouldn’t put too much thought to that. As long as your slab is well-insulated underneath, then putting 5/8ths or ¾ wood flooring on top would not have very little impact on comfort or efficiency. Wood is about R1 per inch, so if you had 6 inches of insulation at R24 underneath then your heat will have little place to go but up.
Radiant floors aren’t the kind of thing you turn down during the day when you go to work anyway, you just set it and leave it generally so it should always be warm. I personally have a radiant floor with engineered wood on top and I’m very happy with it. Here is our page on choosing the best flooring, this may also help you decide.