Radiant Heated Subfloors

Refer to Website or Sample board to confirm as an approved product.

Non Approved products are not warranted for use over Radiant Heat

  • Prior to installation of flooring over radiant heat system it is important that the guidelines are followed in strict accordance. Failure to follow the guidelines may produce unsatisfactory results.
  • Floating installation method only, direct glue down is NOT recommended.
  • Sub floor must be flat to 3/16” in 10’ or 1/8” in 6’
  • Prior to installation moisture testing must be conducted and documented per ASTM test method 1869-89 for concrete or using a pin type meter for wood sub floors.
  • The moisture content for concrete sub floors registered after a calcium chloride test must not be greater than 2 pounds per 1000 square feet of area. If it exceeds these limits, DO NOT install the flooring.
  • Relative humidity of the jobsite must be maintained between 35-55% relative humidity. Use of humidification system may be required to maintain the proper humidity level. Failure to maintain proper humidity level can result in excessive dryness of flooring.
  • It is highly recommended that the radiant heat system be designed specifically to accept a wood floor

1. Use of an in floor temperature sensor as well as a separate thermostat for the individual room is required.

2. An outdoor temperature sensor should be used to adjust water temperature according to anticipated heat loss.



Prior to installation of flooring the radiant system must be installed per manufacturer’s instructions.

Before installation of flooring material the follow conditions are required

1. Moisture content of concrete must not exceed 2.0 lbs per CaCl test method (ASTM1869-89) Wood sub floors not to exceed 12% and be within 4% of the wood flooring.

2. Concrete must be allowed to properly cure and dry a minimum of 4 weeks prior to operation of radiant heat system

3. Operation of radiant heat system should be set to run at 2/3 maximum output for a minimum of 2 weeks prior to installation of flooring to further allow moisture from concrete to dissipate and reach a final moisture content. This must be done in both heating and non heating seasons.

4. Prior to installation (4 days) reduce to a temperature of 65°.

5. Floating Installation - Install flooring according to floating floor installation guidelines. Use of a 2 in 1 underlayment is required.

6. When gluing planks run a continuous bead of adhesive in the groove on both the end and length of the board.

7. Remove any excess glue that squeezes out onto surface of the planks with a clean damp rag. Change rags and water periodically to avoid leaving a haze on surface.



  • 48 hours after completion of installation, slowly raise temperature of the heating system to its preferred operating level over a period of 5 days. Do not allow the surface temperature to exceed 80°
  • Humidity level must be maintained between 35%-55% R.H.
  • Seasonal gapping should be expected.
  • Surface checking can be expected if the proper humidity level is not properly maintained between 35-55% R. H. or if the floor’s surface temperature exceeds 80°.


About warranties regarding radiant heat systems: We have consulted all of our flooring manufacturers - They state that most floors should be OK for radiant heat. As far as them or anyone else giving a specific warranty for their floors over radiant heat, they will not do it. This does not void the flooring warranty itself. The flooring manufacturer cannot be held responsible for issues resulting from radiant heat.

Why? What it boils down to is that no manufacturer can give a flooring warranty for flooring over a heating system that is out of their control. For example, what if the thermostat for the radiant system malfunctions and damages the flooring? Even the companies out there that state their floors are radiant heat approved will not cover the warranty if there is a malfunction with your unit. Unit failure is the cause of issues with floor almost 100% of the time. (faulty thermostats, overheating etc.) The same goes for forced air systems. If your conventional heating or cooling unit malfunctions and gets your flooring outside of specifications – you will not be covered.

Every single company we buy from has the exact same position: Your radiant floor manufacturer is responsible for the warranty on your flooring.