R-Values at a Glance

R-value is defined as a measure of the capacity of a material, such as insulation, to resist heat flow, with increasing values indicating a greater capacity. The higher a material’s R-value, the greater its insulating capacity. Murus SIPs’ R-values range from R-15 to R-77, depending upon the type of foam core and its thickness. R-value testing was conducted at a mean temperature of 75 degrees. Unlike fiberglass batt insulation, Murus foam cores do not sag, shift, settle or compress, or otherwise compromise the integrity of the original R-value rating.

R-Values for Murus SIPs

EPS SIPs
Thickness R-value
4-1/2″ 15
6-1/2″ 23
8-1/4″ 29
10-1/4″ 37
12-1/4″ 45
PUR SIPs
Thickness R-value
4-5/8″ 27
5-5/8″ 34
6-5/8″ 41
GPS  GRAPHITE-ENHANCED EPS SIPs
Thickness R-value
4-1/2″ 17
6-1/2″ 26
8-1/4″ 34
10-1/4″ 43
12-1/4″ 52