CertainTeed FlintBoard® ISO-T Tapered Polyisocyanurate Roof Insulation is manufactured in a tapered profile to offer the combination of high thermal value plus promotion of proper roof drainage.

FlintBoard ISO-T tapered polyiso roof insulation is specifically recommended for hot asphalt, coal tar BUR, modified bitumen and single-ply membrane roofing systems. FlintBoard ISO-T is also available in 25-psi formula. It is produced in a variety of thicknesses; 4' x 4' panels only.

Technical Information

CertainTeed ISO-T is offered in a variety of thicknesses, providing long-term thermal resistance (LTTR) values from 4.5 to 15.3. Higher LTTR values can be achieved with layers of flat ISO. FlintBoard ISO-T is a closed-cell, polyiso core integrally laminated to heavy, black (non-asphaltic), fiber-reinforced felt facers. FlintBoard ISO-T is also available in 25-psi formula. Available in 4' x 4' (1220mm x 1220mm) panels only.

For additional technical resources please refer to the CertainTeed Commercial Roof Systems Manual.


Before installation begins, the roof deck must be firm, well attached, even, clean and dry.

Do not leave exposed. FlintBoard ISO-T is a polyiso organic plastic foam and will burn if exposed to an ignition source of sufficient heat and intensity, or open flame, such as a welder's torch. Do not apply flame directly to FlintBoard roof insulations .

For detailed installation instructions please refer to the CertainTeed Commercial Roof Systems Manual.

For Construction Details and Specs Click Here

Warranty Details

CertainTeed offers three asphaltic low-slope roof system warranty options: Limited Warranty on Materials, Integrity Roof System Limited Warranty, and Integrity Roof System No Dollar Limit (NDL) Limited Warranty. CertainTeed warranty durations are based on a combination of system specification and product selection. Please download an overview of these warranty options for details. Consult with your contractor or CertainTeed Territory Manager to determine which warranty is best for your project.     

CertainTeed offers standard asphaltic low-slope roof system warranty durations between ten and twenty-five years. Additionally, Gold Star Contractors can increase warranty durations by 25% by engaging in an Integrity Maintenance Agreement with their client.

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