When installing the radiant-baseboard heating system in my new home, I got creative with the heating setup in the master bath. I wanted a little extra warmth in the tile floor, so I ran the copper supply line for the zone’s radiator back and forth in the bathroom’s joist bays, as shown in the drawing. I was careful to steer at least 18 in. clear of the toilet’s wax ring to avoid deforming the seal.
I insulated each of these joist bays with 4 in. of rigid insulation, topped with reflective aluminum flashing to direct heat upward. I also insulated the ends of the joist bays.
The result: a toasty bathroom floor. This worked so well that I did the same detail in several other accessible joist bays in the house, creating particularly warm areas that bare toes and pets enjoy.
Jim Benton, Riner, VA