R-Board
Rboard® Exterior Wall Insulation
Rboard® is a non-ozone depleting, versatile substrate that can be used behind a variety of exterior cladding.
Rboard® sheathing is a rigid polyiso foam insulation panel with a specially coated and patented facer on both surfaces. It is one of the most cost effective, energy efficient sheathing materials available in the marketplace.
When properly installed, Rboard® wall insulation will provide added insulation and yield immediate energy savings in both Commercial and Residential applications. R-values range from 3.0 to 21.7, depending on thickness.
R-values: Rboard®
| Standard Thickness | in | 1/2 | 5/8 | 3/4 | 1.0 | 1.5 | 2.0 | 2.5 | 3.0 | 3.5 |
| mm | 13 | 16 | 19 | 25 | 38 | 51 | 63.5 | 76.2 | 88.9 | |
| R-value* | 3.0 | 3.8 | 4.5 | 6.0 | 9.0 | 12.1 | 15.3 | 18.5 | 21.7 | |
| RSI | .53 | .67 | .79 | 1.06 | 1.58 | 2.13 | 2.69 | 3.26 | 3.82 | |
| Pieces Per Package | 42 | 34 | 29 | 22 | 15 | 11 | 18 | 15 | 13 | |
| 4' x 8' Size - sq. ft./Pkg | 1344 | 1088 | 928 | 704 | 480 | 352 | 576 | 480 | 416 | |
| 4' x 9' Size - sq. ft./Pkg | 1512 | 1244 | 1044 | 792 | 540 | 396 | 648 | 540 | 468 | |
* Conditioned thermal values were determined by ASTM Test Method C 518 at 75 F mean temperature. All test specimens were conditioned in accordance with procedures outlined in ASTM C 1289-07, Section 11.1.2.1 Note: Canada’s CCMC has set all polyiso foam R-values at 6.0 per inch - straight line - for all available thicknesses. Published R-values are determined by ASTM C518 | ||||||||||
Rboard® Applications
For specific information about all Atlas Sheathing applications, please download the Atlas Insulating Sheathing Installation Details. Rboard® is typically specified for:
- Exterior Wall Applications
- Fire Resistant Wall Assembly (1 Hour)
- Insulated Crawl Space
- Interior Insulation Slab on Grade
- Interior Insulation Under Slab
- Cavity Wall/Masonry Insulation
- Metal Stud Wall Applications
- Re-Siding Applications
- Stucco Applications (Hardcoat)
ASHRAE Standard 90.1 and Continuous Insulation
ASHRAE Standard 90.1 is the energy code reference in the International Building Code (IBC) and the International Energy Conservation Code (IECC). As such, this standard defines code minimums for the classes of constructions covered. In 2008, for the first time in over 19 years, ASHRAE increased the minimum required prescriptive R-value (resistance to heat flow) for roof and wall insulation levels in Standard 90.1
The next IRC and IBC code cycles will require the installation of a layer of continuous insulation over the entire exterior of walls of residential and commercial construction. This requirement will provide for a "thermal break" and added R-value to the structure - making the building much more airtight and energy efficient, as compared to current and past required construction. Foam insulation with an R-value of 5 will be the minimum acceptable continuous insulation. Atlas Rboard® polyiso foam insulation at 1.0" thick provides an R-value of 6.0. Atlas recommends thicker insulation and promotes Beyond the Code initiatives that work to create more energy efficient buildings today for a greener tomorrow.
Water Resistive Barrier System
Rboard® is a component of a wall system recognized as a Water Resistive Barrier by the International Residential Code Report #ESR-1375. See the WRB Tapes and System page for more information.


