ASTM C303
Standard Test Method for Dimensions and Density of Preformed Block and Board-Type Thermal Insulation
What it measures
Measures the actual dimensions and density of an insulation board.
Why it matters for a panel envelope
Density is the property that drives EPS strength and R-value, so it is the number to verify on delivery.
Guardian Shield™
The Shield™ EPS core has a minimum density of 0.90 pcf.
Source · 3-Part Specification, 1.3 F.9 and 1.5 E.5 a · Guardian documents
Written by Data Subsystems, for Guardian Structural Technologies. Last updated .
Drafted from Guardian Structural product literature and published building-science sources. Awaiting Guardian technical review. Confirm any figure against the current product documents or ask us before you rely on it in a design.