Stevens Iso-2000 is a closed-cell, polyisocyanurate core integrally laminated to heavy black (non-asphaltic), fiber-reinforced felt facers. Stevens Iso-2000 Insulations are specifically recommended for single-ply membrane systems, hot asphalt or coal tar BUR and modified bitumen. Stevens Iso-2000 has a perforated facer on one side for use with hot-applied systems and a non-perforated side for single-ply systems, making this a universally adaptable insulation product suitable for a variety of applications. 

Stevens Iso-2000 Tapered Insulation is manufactured in a tapered profile to provide positive drainage while maintaining maximum thermal efficiency. All Stevens Iso 2000 is made with a standard 20-psi formula; however, a 25-psi formula is available. 

Panel Sizes

Iso 2000 -- 4 x 8-ft. (122 x 244-cm) panels only
Iso 2000 Tapered -- 4 x 4-ft. (122 x 122-cm) panels only

Compliance
• Federal Specification HH-1-1972/2, Class 1 
• ASTM C 1289-95, Type II.
• IBC, BOCA, ICBO and SBCCI Sections on Foam Insulation

Long-Term Thermal Resistance (LTTR) 

Long-Term Thermal Resistance (LTTR) is an advanced, scientifically supported method (based on ASTM C 1303-95) of predicting the Long-Term Thermal Resistance of polyisocyanurate insulation products, such as Stevens Iso.  LTTR provides specifiers, design professionals, and roofing contractors many advantages, including:

• A Long-Term Thermal Design Value (15 year time-weighted average)
  
• A better understanding of thermal performance of foam
  
• An advanced test method, based upon consensus standards used by both US and Canada
  
• A technically supported, prescriptive method to measure the Long-Term Thermal Resistance (LTTR) of polyiso foam insulation
  
• Long-Term Thermal Resistance (LTTR) values are required in the mandatory annex of ASTM C 1289-02

The roofing industry now has a definitive standard for predicting Long-Term Thermal Resistance (LTTR) values. The new Long-Term Thermal Resistance (LTTR) values became effective July 1, 2002 in Canada and January 1, 2003 in the United States. The *Long-Term Thermal Resistance (LTTR) values of the foam were determined in accordance with CAN/ULC-5570.  All test samples were third-party selected and tested by an accredited materials testing laboratory.

 

 

 

 

 

Stevens Iso 2000 Long-Term Thermal Resistance*
Thickness	LTTR* Value	Thickness	LTTR* Value
1.0	6.0	2.6	15.9
1.1	6.6	2.7	16.6
1.2	7.2	2.8	17.2
1.3	7.3	2.9	17.9
1.4	8.4	3.0	18.5
1.5	9.0	3.1	19.1
1.6	9.6	3.2	19.8
1.7	10.3	3.3	20.4
1.8	10.9	3.4	21.1
1.9	11.5	3.5	21.7
2.0	12.1	3.6	22.4
2.1	12.8	3.7	23.0
2.2	13.4	3.8	23.7
2.3	14.0	3.9	24.3
2.4	14.7	4.0	25.0
2.5	15.3

Click here for additional LTTR information or to use the LTTR Calculator 

Stevens Iso-2000 Tapered Insulation
Marking	Nominal Thickness	Slope per Foot	Average R-Value
AA	.05 - 1.0-inch	1/8-inch	4.5
A	1.0 - 1.5-inch	1/8-inch	7.5
B	1.5 - 2.0-inch	1/8-inch	10.6
C	2.0 - 2.5-inch	1/8-inch	13.7
X	0.5 - 1.5-inch	1/4-inch	6.0
Y	1.5 - 2.5-inch	1/4-inch	12.1
G	1.0 - 2.0-inch	1/4-inch	9.0
H	2.0 - 3.0-inch	1/4-inch	15.3
JJ	0.5 - 1.25-inch	3/16-inch	5.2
KK	1.25 - 2.0-inch	3/16-inch	9.8
Q	0.5 - 2.5-inch	1/2-inch	9.0