Wood actually acts as an insulator more so than thermal mass. The amount of insulating property is dependent on the density of the wood.For example a hard wood would have a lower R value since the fibers are more closely arranged than a soft wood.
As for heat transfer, engineered wood floors are thinner, approximately 3/8" in thickness allowing heat to transfer to the living space more quickly than a 3/4" solid wood floor.
If you are considering the installation over a radiant heat floor system, here are a few tips to keep in mind:
- Install a radiant heat floor system which has an integral aluminum heat shield. This will direct the heat upward as well as distribute the heat evenly across the floor.
- For your reference look into "Warmboard" subfloors.
- If installing an engineered floor, verify with the manufacturers that it is approved for radiant heat floor systems.
- If clearance allows, install a minimum of 1.5" of light weight gypcrete over the radiant heat tubes. The gypcrete will act as your thermal mass and distribute the heat evenly across the floor.
Good Luck, Harold Remlinger, AIA Principal Architect DesignTeam Plus, LLC