Insulating Above the Purlin - White Interior - New Roof for Post Frame Building and Pole Barn

Insulation Above Purlin - White Interior - New Metal Roof Application

Installation Instructions

  • After the trusses are set, run two purlins to make sure the trusses stay true.

  • Install purlins. Nail or screw to the trusses.

  • The InfraStop® insulation is installed with the "white side" towards the interior of the building.

  • Attach the InfraStop® double bubble product white insulation to the purlins with at least 5/16” staples. Temporarily nail a 2” x 4” block over the end of the product at the starting edge to prevent it from pulling away.

  • Roll out the product across the top of the purlins, When installing product, insure that a minimum of a 3/4” drape (middle of cavity) is present between the trusses.

  • Run subsequent course of the product with the ¾” staple tabs overlapping or square edge butting or overlapping at the seams.

  • Tape the seams with InfraStop® Foil Tape (goal is an air-tight, snug seam seal).

  • Install the metal roof to the purlins.

Standard Size Rolls for Barns: Square Edge and Staple Tab

Custom Size Rolls for Barns: Square Edge

Thermal Insulation

Open Interior - R-3.8* Heat Flow Down (and a Radiant Barrier) | R-3.5* Heat Flow Up

Please Note: In addition to the stated R-value, this application also provides a Radiant Barrier. As a result, a 94% + reduction of the radiant energy that ordinarily would be transmitted to the interior of the building is blocked.

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

Product Information

InfraStop® Insulation products are a group of technologically advanced materials. They are ideal for new construction or retrofit applications in commercial, industrial, metal and post/frame buildings, along with many other DIY applications. When you think of insulation, you should think of InfraStop®. Our products are recognized for their thermal performance, easy installation, versatility, price and environmental friendliness.


  • 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

Testing and Certification

InfraStop® 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. For a copy of an actual test report, please e-mail us at

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