Radiant Floor – In a Subfloor


Note: Installation instructions and illustrated drawings are recommendations only, while proper local construction methods are the responsibility of the installer.

Reflectix® has an insulating upgrade available for a radiant floor system installed in a sub-floor. The addition of this Reflective Insulation into this radiant floor assembly will result in a higher level of energy efficiency and a more even floor surface temperature. The bonus characteristic to this product is how easy it is to handle and install.

Product Description

The Reflectix® Double Reflective Insulation consists of two layers of highly reflective film (96% reflectivity) that are bonded to two tough layers of polyethylene. Two inner layers of insulating bubbles and a center layer of polyethylene provide this easy to handle product with high strength and reliability.


  • Reduces installation labor because of its easy to handle and install characteristics
  • Reflects 96% of the radiant heat back into the living space
  • Reduces annual energy costs of the system
  • R-4.6
  • Directs heat into living space
  • Enhances even heat distribution across the floor surface
  • Fiber-free
  • Non-toxic / non-carcinogenic
  • Does not promote the nesting of
  • ISO 9001:2015 certified manufacturing location insects

Part Numbers and Sizes

  • HVBP48125 (48”x 125’)

Technical Data

  • Temperature Range: -30 to 180 F
  • Flame Spread: Under 25 *
  • Smoke Development: Under 50 *
  • Perm Rating: .02 **
  • Puncture Resistance: 60 lb./in. ***
  • Vapor Transmission .02
  • Mold and Mildew: No Growth
  • Emittance: 0.04
  • Pliability: No Cracking
  • Hot Surface Performance: Passed

* ASTM Test Method E-84 • ** ASTM Test E96 *** FSTM 101 B Method 2031

Testing and Certification

  • Thermal Performance Calculation – R&D Services
  • Emittance ASTM C1371
  • Permeance ASTM E96/E96M
  • Flame Spread and Smoke Density ASTM E84
  • Hot Surface Performance ASTM C411
  • Humidity Resistance ASTM C1258
  • Adhesive Performance ASTM C1224
  • Pliability ASTM C1224
  • Fungi Resistance ASTM C1338
  • Puncture Resistance FSTM 101 B Method 2031

Installation Instructions

Note: Installation instructions and illustrated drawings are recommendations only, while proper local construction methods are the responsibility of the installer.

Note: For all methods (retrofit), inspect the structural integrity of the sub-floor, and make any needed repairs before installing Reflectix®.

  • Unroll the Reflectix® Reflective Insulation over the existing floor. Cut product flush with the walls.
  • Butt the seams of the insulation and seal with 2” wide foil tape. Note: Utilize a flat edge taping tool to assure good adhesion on all tape.
  • Install Radiant Floor System per manufacturer’s specifications, sleepers and new (top) subfloor.


Review These Important Safety Guidelines Prior to Installation:

  • ALWAYS check local building codes before installing Reflectix®.
  • ALWAYS check the area you are insulating and make any needed repairs. Any worn wiring should be replaced before you begin installing Reflectix®.
  • ALWAYS make sure work areas are well ventilated and well lighted.
  • ALWAYS use eye protection when operating a staple gun.
  • ALWAYS use caution and common sense when using a staple gun. Be aware of electrical wiring locations. Stapling into a wire can cause severe shock or death. NEVER staple into electrical wiring.
  • ALWAYS be careful when working with large pieces of Reflectix® on windy days.
  • When installing Reflectix® on bright sunny days, it is best to wear sun glasses.
  • Do not work in areas such as attics when temperatures are too hot.
  • Please Note: The intention of these Installation Instructions and 3-D renderings are for the sole purpose of illustrating the correct location and relative position of the Reflectix® products in specific building assemblies. The correct construction methods and techniques are the responsibility of the installer or contractor. The methods outlined are recommendations on location of the Reflectix® products as a guideline. There are no claims on the part of Reflectix, Inc. that these building assemblies are finite standards or meet building code requirements (as they can vary by region).

Reflectix Fact Sheet per FTC


Pictured: Double Reflective Insulation