STYROFOAM Square Edge
Radiant Floors Application Information Sheet (98KB PDF)
Installation Instructions for STYROFOAM™ Square Edge
STYROFOAM Square Edge extruded polystyrene insulation is a foam insulation board with square edges on four sides. It offers superior water resistance, long-term thermal performance and high compressive strength.
| Nominal Board Thickness** |
R-Value† |
Board Size |
Edge Treatment |
Min Compressive Strength†† |
| 0.75" |
3.8 |
2' x 8'/4' x 8' |
Square Edge |
25 psi |
| 1.0" |
5 |
2' x 8'/4' x 8' |
Square Edge |
25 psi |
| 1.5" |
7.5 |
2' x 8'/4' x 8' |
Square Edge |
25 psi |
| 2.0" |
10 |
2' x 8'/4' x 8' |
Square Edge |
25 psi |
| 2.5" |
12.5 |
2' x 8'/4' x 8' |
Square Edge |
25 psi |
| 3.0" |
15 |
2' x 8'/4' x 8' |
Square Edge |
25 psi |
| 4.0" |
20 |
2' x 8'/4' x 8' |
Square Edge |
25 psi |
Building Code Compliance
Complies with ASTM C578 Type IV. Meets IBC/IRC requirements for foam plastic insulation. See ICBO-ES ER 2257, BOCA-ES RR 21-02, NES NER 699, Und. Lab. Inc.® Classified, see Classification Certificate D369.
**Not all product sizes are available in all regions.
†R means resistance to heat flow. The higher the R-value, the greater the insulating power. R-values are expressed in ft2•h•°F/Btu.
††Vertical compressive strength is measured at 10% deformation or at yield, whichever occurs first.
