LTTR Values Update

Starting January 1st, 2014:

  • GenFlex Roofing Systems will continue to participate in the Polyisocyanurate Insulation Manufacturers Association (PIMA) QualityMark cm Certification Program
  • GenFlex Roofing Systems will offer the same Polyiso Insulation
  • Only Polyiso R-values are changing
  • They are changing to meet the new ASTM C1289-13e1 testing methods


Please click here to read the full bulletin outlining GenFlex Roofing Systems R-Values and explanation of ASTM C1289-13e1.


Frequently asked questions about the new Polyiso LTTR values:


 1. When will the new LTTR values go into effect?

GenFlex Roofing Systems will publish LTTR values according to ASTM C1289-13e1 effective January 1st, 2014. Any quotes for jobs in 2014 should be based on ASTM C1289-13e1 standards.


2. What is ASTM C1289-13e1?

In order to provide a comprehensive approach to predicting long-term R-value throughout North America, the updated ASTM C 1289-13e1 standard now incorporates two test methods, ASTM C1303-11 and CAN/ULC-S770-09, which offer a similar approach to predicting the long-term thermal performance for foam insulation materials that exhibit air and blowing agent diffusion or aging over time. Both test methods employ a technique called “slicing and scaling” to accelerate this aging process and provide an accurate and consistent prediction of product R-value after 5 years, which is equivalent to a time-weighted thermal design R-value for 15 years. The update to ASTM C1289-13e1 in no way impacts polyiso’s physical properties.


3. What has changed about Polyiso?

Nothing. GenFlex Polyiso Insulation products have not changed. The polyiso foam and facers remain the same. Only the Long Term Thermal Resistance (LTTR) testing methodology has changed, which leads to the new published LTTR values.


4. Why have the LTTR values changed?

The LTTR values have changed so the industry has more accurate data. As newer, more precise testing methods are introduced, the Polyisocyanurate Insulation Manufacturer’s Association (PIMA) and its members are able to report R-values associated with this new methodology. Polyiso is the only insulation to be 3rd party certified for its LTTR value.


5. How do I price jobs that include Polyiso in 2014?

Any quotes for jobs in 2014 should be based on the new ASTM C1289-13e1 standards. GenFlex Roofing Systems recommends that thicknesses and the LTTR values of the products should be included in your bid.


6. How does this affect tapered Polyiso?

GenFlex Roofing Systems Estimating Services will use the new LTTR values in tapered system quotations starting January 1st, 2014. Prior to that time, specifiers and contractors can inform the estimators of their requirements and LTTR value needs, and GenFlex will quote the tapered system accordingly.


2015 LTTR Values

PIMA QualityMark(CM) announcement of reporting ASTM C 1289-11 LTTR Values

Explanation of the PIMA QualityMark(CM) Certification Program


Additional information can be found here and here.