LTTR
A method-based representation of aged thermal resistance used for specified insulation products.
Also called: long-term thermal resistance
Material family: Construction, roofing and geosynthetics
Where it matters
Comparing declared insulation performance.
Testing and verification
It is not a service-life guarantee or a complete roof-system rating; confirm product and reporting basis.
Related guides
Related products and materials
Technical references
General information for preliminary evaluation; not independently reviewed or certified. Confirm grades, standards and suitability with the manufacturer for your application. Interpret within the exact material, grade and test method.