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 (94%+ 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 94%+ 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 9001:2008 certified manufacturing location insects

Part Numbers and Sizes

  • HVBP48125 (48”x 125’)

Technical Data

  • Temperature Range: -60 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: Less than 0.06
  • 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).


Pictured: Double Reflective Insulation

Standard Edge 72 RGB