Three Inch Rule and Why It Matters

Providers of TAP® Pest Control Insulation stand behind the product due to its pesticide performance and energy efficiency savings. A second-tier benefit is the product’s flame retardancy. However, when TAP® Pest Control Insulation is installed in a home, a barrier must be installed around all heat producing devices. This is a discussion of the three inch rule and why it matters. 

TAP®’s Flame Retardancy

 The comfort of homeowners is one of the priorities of TAP® Pest Control Insulation. Therefore, TAP® Pest Control Insulation meets or exceeds all necessary fire safety requirements conducted in accordance with ASTM standards: 
Critical Radiant Flux: >0.12 w/cm 2
Smoldering Combustion: <15%

The reaction of TAP® Pest Control Insulation to open flame is a blackening and charring of the material. TAP® Pest Control Insulation does not act as a conduit but instead slows or retards the spread of fire. This is simply another benefit of this innovative pesticide. 

Heat Producing Devices

Here is a list of some of the more commonly found heat-producing devices found in an attic:

  • Recessed lights
  • HVAC systems
  • Chimneys and exhaust flues
  • Furnaces
  • Attic fans or whole house fans

What Does the Law Say and Why it Matters?

According to the Electronic Code of Federal Regulations (eCFR), installers of any type of cellulose insulation including TAP® Pest Control Insulation are instructed to “keep cellulose insulation at least three inches away from the sides of recessed light fixtures. Do not place insulation over such fixtures so as to entrap heat.” The code goes on to say “Also, keep this insulation away from exhaust flues of furnaces, water heaters, space heaters, or other heat-producing devices.”

Practical Implication

Following the code is simple and guidance is given. “To be sure that insulation is kept away from light fixtures and flues, use a barrier to permanently maintain clearance around these areas.” We all know that clearance is a subjective term. So, just how should installers build this three inch barrier around heat-producing devices. 

How to Build a Three Inch Barrier

There are many ways to build a three inch barrier when installing TAP® Pest Control Insulation in an attic cap or attic restoration installation service. Here are the most common:

  1. cardboard or tin shielding is often placed over recessed lights with a quick and simple installation process
  2. Blue Board, Green Board, or STYROFOAM™ Brand Foam for Construction can be used to create a barrier or dam around HVAC units, chimneys, and exhaust flues. This requires a bit of minimal construction by cutting and taping the board into place. Thin plywood held together with screws can also work if necessary.
  3. Non-woven netting can also be used in barriers around chimneys, exhaust flues, and attic fans. It is easy to use by simply stapling the netting into place.

In Conclusion

When installing TAP® Pest Control Insulation in an attic, remember the three inch rule and why it matters. This will help earn your customer’s trust and produce a quality installation. Looking for additional information on the three inch rule or the TAP® installation process, contact us today. 

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