Prodex radiant heat floor insulation provides R value, vapor and radiant heat barrier protection. It is an effective is regulating the temperature of your floor. Prodex reflects 97% of the radiant heat (primary source of heat-flow) upwards towards the flooring - Keeping the heat inside! This allows your heating system to operate more efficiently thereby saving you money. Walk barefoot on a comfortable floor!
Depending on your stud spacing, you can use Prodex 16, 24 or 48 Inch. Prodex 16 Inch and 24 Inch are typically stapled between the studs (first diagram below). You could use Prodex 48 inch and run it continuously under the joists (second diagram below).
Click for installing radiant floor insulation under a wood floor