Product: Reflective One Side

Post Frame Building – Roof – New

Below the Purlins
Open Interior
R-6.4* Heat Flow Down | R-3.7* Heat Flow Up

Above the Purlins
Open Interior
R-3.8* Heat Flow Down | R-3.5* Heat Flow Up

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

Reflectix® Insulation products are a technologically advanced Insulation material ideal for new construction or retrofit applications in commercial, industrial, metal and post/frame buildings. Our products are recognized for their thermal performance, easy installation, versatility and price.

Recommended Products

Single Reflective Insulation

Reflective/Bubble/Bubble/White – Roll

  • RDBW48100 (48” x 100’)


  • Easy to handle and install
  • Convenient roll sizes
  • Class A / Class 1 Fire Rating
  • Inhibits dew point condensation
  • Vapor retarder (0.02 perms)
  • Does not compress, collapse or disintegrate
  • Non-toxic / non-carcinogenic

Installation Instructions

Installation Instructions: (There are 2 options)

Installation Instruction pdf: PFB1 Roof New Revised 012021

1. Metal Roof with Product Below Purlin

  • The Reflectix® Insulation is installed with the “white side” towards the interior of the building.
  • After the trusses are set, run two purlins to make sure the trusses stay true.
  • Attach the Reflectix® Reflective/Bubble/Bubble/White product to the first truss with at least 5/16” staples. Temporarily nail a 2”x 4” block over the end of the product to prevent it from pulling away.
  • Roll out the product across the top of the trusses, pull tight and staple.
  • Run subsequent courses of the product with a 3/4” overlap at the seams.
  • Tape the seams with a Reflectix® Foil Tape (goal is an air-tight, snug seam seal).
  • Install purlins over the insulation. Nail or screw to the trusses through the product.
  • Install the metal roof to the purlins.

2. Metal Roof with Product Above Purlin (see illustration above)

  • Per instructions above except install Reflectix® Reflective/Bubble/Bubble/White Insulation after installing the purlins.
  • When installing product, insure that a minimum of a 3/4” drape (middle of cavity) is present.

* Includes thermal resistance of 0.61 UP and 0.92 DOWN for interior air film.

Calculation Disclaimer: All values are calculated based on the “ASHRAE Handbook of Fundamentals” heat flow up and down.


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).

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 the “Additional Resources” tab. The documents are also available by e-mail at or call (800) 879-3645.


Pictured: 1. Single Reflective Insulation