ECOWARM may be used under traditional strip wood flooring in several ways. A conventional nailed and hardwood type system may be used directly over EcoWarm, and with controls as described in the previous section. There are many advantages to this method; they include quicker response, lower cost of installation, higher heat output due to lower resistance of flooring, and a indoor or outdoor reset control that brings the flooring through temperature changes evenly, gradually and accurately.
Optional floating methods for use with traditional strip wood flooring: 2 layers of 1/2-inch plywood may be floated on top of EcoWarm and strip flooring nailed to it, as shown below in a method recommended by the National Wood Flooring Association. This method has the advantage that it allows the wood flooring system to float independently from EcoWarm, but has significant disadvantages in that the 1” extra thickness of wood limits the output of the system. For example, two layers of 1/2” plywood with 3/4” of strip oak flooring has an R-value of about R-2.3. This limits the output of the floor at 150° F water temperature to about 26 BTU/Square Foot. A careful heat loss analysis must be done to see if this method will produce enough heat. If not, another method should be chosen or provisions made for backup heat. A hydronic control strategy that gradually adjusts water temperature going to EcoWarm with a reset curve is recommended but not required with this method.
Clip style floating strip flooring systems must be installed directly over EcoWarm such that clips will never come in contact with the tubing.
The use of a floating engineered wood is a preferred method. This product should have a specific warranty for use over radiant floors. Many manufacturers of these products have such a warranty, as well as having extensive experience both in Europe and North America with radiant heating applications. Edge glued floating engineered wood flooring systems are preferred, since they are dimensionally stable and expand independently from any thermal mass. EcoWarm should be installed such that the hardwood runs perpendicular to the majority of the tubing runs.
Glued down wood flooring systems are not recommended unless a layer of plywood is first screwed down to the EcoWarm and the wood is attached to the plywood according to the flooring manufacturer’s recommendations for installation over radiant heat.