Pro
Radiant Floor - Wood Joists

Up to R-21 and a Radiant Reflector (Maximum Benefit Application)

This application is ideal for a radiant floor system above or below a wooden (joist) sub-floor. The benefits provided by Reflectix® are dramatic. In addition to an impressive R-21, the reflective film provides a 94% + reflectivity of radiant energy back into the system. The product has the added attraction of ease of handling and installation.

Recommended Products:
Double Reflective Insulation
Staple Tab, Reflective/Bubble/Bubble/Reflective - Roll
• ST16050 (16” x 50’)
• ST16100 (16” x 100’)
• ST16125 (16” x 125’)
• ST48050 (48” x 50’)
• ST48100 (48” x 100’)
• ST48125 (48” x 125’)

Benefits:
• Up to R-21
• Reflects 94% + radiant energy back up into sub-floor
• Reduces annual energy costs of the system
• Installs quickly and easily
• Product is dust and fiber-free
• Does not require any protective garments or respirators
• No nesting characteristics for insects or rodents

Testing and Certification:
Reflectix® products are thoroughly tested at either nationally approved, independent laboratories or leading universities. Tests are performed to current American Society of Testing and Materials (ASTM) standards when a standard exists. To obtain a copy of our Product Testing Specifications, please refer to our website “Literature Tab” above. The documents are also available by e-mail at customerservice@reflectixinc.com or call 800-879-3645.

Federal Trade Commission Fact Sheet: Installation Instructions:
There are 5 Methods of Installation (with varying levels of benefit)

Download Pro Radiant Floor - Wood Joists Installation Instructions 1114.pdf
Note: Installation instructions and illustrated drawings are recommendations only, while proper local construction methods are the responsibility of the installer.
Note: For all methods, inspect the structural integrity of the sub-floor and make any needed repairs before installing Reflectix®.

1. Product (Double Layer) Installed to Underside and Inside of Floor Joist - R-17 and a Radiant Reflector
• Begin at one end of the house. Insert the first course of Reflectix® half way up into the joist cavity and staple (at approximately 3” to 4” intervals) the edge of the product to the side of the joist. The goal is to split the joist cavity into two approximately equal enclosed air spaces.
• Continue with the second course of product at one end of a joist cavity (after the first course has been installed) and secure the product “end” with staples to the sub-floor or band board. Proceed down the joists by stapling each edge (or middle of the Reflective/Bubble/Bubble/Reflective 48” wide product) to the face of each joist. Staple the product at intervals of approximately 3” to 4”.  Enclose the entire joist run(s).
• Seal seams with Reflectix® Foil Tape to create a vapor/moisture barrier.
• Repeat for each joist that contains the Radiant Floor System.

2. Product Installed to Underside of Floor Joist - R-17 and a Radiant Reflector
• Begin at one end of a joist cavity (that contains the Radiant Floor System) and install the product “end” with staples to the sub-floor or band board. Proceed down the joists by stapling each edge (or middle of the Reflective/Bubble/Bubble/Reflective 48” wide product) to the face of each joist. Staple at intervals of approximately 3” to 4”. Enclose the entire joist run(s).
• Seal seams with Reflectix® Foil Tape to create a vapor/moisture barrier.
• Repeat for each joist that contains the Radiant Floor System.

3. Product Installed Inside the Joist Cavity - Diminished R-Value / Radiant Reflector
• It is possible to install the Reflectix® inside the joist cavity (utilizing the Reflective/Bubble/Bubble/Reflective, Staple Tab product).
• Start at one end of the house. Tuck the Reflectix® into the joist cavity.
• Each edge of the product has a 3/4” staple tab. Determine the depth inside the cavity that the product is to be installed and attach the product with staples (through the tab) at approximately 3” to 4” intervals. Repeat on opposite joist.
• The less air space between the product and the sub-floor, the lower the R-Value (although reflectivity will be maintained).
Examples of benefits based on air space width above product:
• 0.5” air space = R-2.7
• 0.75” air space = R-4.6
• 3.5” air space = R-8.2

4. Product Installed Inside the Joist Cavity with Mass Insulation Below
Diminished R-Value / Radiant Reflector
• It is possible to install the Reflectix® inside the joist cavity above a Mass Insulation Batt.
• Utilize Reflective/Bubble/Bubble/Reflective, Staple Tab product Method specified in #3.
• Refer to R-values in Method #3 to determine benefit gain in your system.

5. Product Installed Inside the Joist Cavity with Mass Insulation Above R-2.7 with a 0.5” Enclosed Air Space  or R-4.6 with a 0.75” Enclosed Air Space
• Reflectix® can be installed below the Mass Insulation Batt.
• Refer to Method #3 for installation procedure, air space options and resulting R-Values.
• Finish with an interior panel below the Reflectix® (typical when finishing a basement).

Important:

Additional Resources:
Zip Code Zone Locator
This function provides regional installation recommendations for the following applications: Attic & Cathedral Ceiling
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DIY Product Calculator Type:
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*Note: This calculator is for the convenience of our customers. These recommendations are for approximate product quantity.

Video Library:

For additional videos, click here.
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