THERMAX* Sheathing is a polyisocyanurate foam core with unique glass fiber
reinforcement and solid aluminum foil facers on both sides. This reinforcement,
along with chemical modifications, contributes to improved fire performance and
enhanced dimensional stability. THERMAX Sheathing is available in standard widths
of 16", 24" and 48", with lengths from 4' to 30' (8', 9' and 10' standard).
Applications
THERMAX Sheathing is a high performance insulating sheathing for residential or
commercial construction, interior basement, or exterior cavity wall applications.
It's especially appropriate for time-rated assemblies. Corner bracing is required
in new frame construction.
Not all sizes available for all applications.
Dow is transitioning to a new blowing agent. As a result, current R-values are
changing. New R-values are referenced in the chart provided.
| THERMAX Sheathing |
|---|
Nominal Board Thickness
in. (mm) |
Current R-value1 |
Current R-value2 |
| .5 (12.7) |
3.6 |
3.3 |
| .75 (19.1) |
5.4 |
5.0 |
| 1 (25.4) |
7.2 |
6.5 |
| 1.25 (31.8) |
9.0 |
8.0 |
| 1.55 (38.1) |
-- |
10.0 |
| 1.75 (44.5) |
12.6 |
11.4 |
| 2 (50.8) |
14.4 |
13.0 |
| 2.5 (63.5) |
18.0 |
15.8 |
| 3 (76.2) |
21.6 |
19.0 |
| 3.5 (88.9) |
25.2 |
22.1 |
| 4 (101.6) |
28.8 |
25.3 |
1 R-values @ 75° F (24° C) mean temperature determined in accordance
with ASTM C236/C518.
2 R-value determined by ASTM C518
|
