Applying a radiant floor underlayment such as Ecowarm RadiantBoard over a subfloor provides the fastest responding, efficient distribution of warm water radiant heat. We prefer applying our panels over a conventional subfloor rather than an integrated thick structural radiant panel because our over subfloor systems are more easily installed in the flow of building construction and are less expensive to install, even when including the cost of a conventional subfloor.

Applying radiant heat under a subfloor significantly increases the resistance to heat transfer resulting in higher water temperatures, low system efficiency and slower response time, and often challenging insulation application conditions. We recommend using this type of system only if the chief design criteria are maintaining existing flooring goods, such as hardwood in a remodel.