Use drainable bedding and design the pavement for its traffic loads.
The attached ICPI Tech Spec 12 recommends suitable bedding sand and warns against limestone screenings or stone dust because excessive fines slow drainage. Use the sand gradation and bedding design specified for the pavement; do not substitute a fine-rich material simply because it compacts easily.
Choose paver thickness and base construction for the traffic and structural design as well as the heating layout. Tech Spec 12 recommends 60 mm (2⅜-inch) pavers for pedestrian and residential driveway applications and 80 mm (3⅛-inch) pavers for other vehicular uses. These examples are not a universal 2½-inch maximum for heavy loads.
Coordinate the selected paver, bedding thickness, cable depth and spacing with the WarmlyYours snow-melting design. Drain meltwater to a suitable location so it does not refreeze on adjacent unheated areas. The attachment discusses both hydronic and electric systems; a general application example does not override an electrical-code restriction or the heating cable’s installation instructions.
Source: attached ICPI Tech Spec 12, “Snow Melting Systems for Interlocking Concrete Pavements,” especially Bedding Sand, Concrete Pavers and Drainage.
