Molded plastic structures

A blow-molded plastic structure constructed using a blow-molded process, the blow-molded plastic structure comprising:

• a panel comprising a first surface, a second surface, and a hollow interior portion disposed between the first surface and the second surface;
• a lip extending outwardly from the panel, the lip including an outer surface and an inner surface;
• a plurality of curved risers extending inwardly from the inner surface of the lip, each riser of the plurality of curved risers connected to the panel and the inner surface of the lip;
• and
• a plurality of elongated tack-offs, an elongated tack-off of the plurality of elongated tack-offs disposed between a pair of curved risers of the plurality of curved risers, the elongated tack-off having a length at least three times greater than a height of an adjacent curved riser.

A blow-molded plastic structure constructed using a blow-molding process, the blow-molded plastic structure comprising:

• a generally planar panel including a first surface, a second surface, and a hollow interior portion disposed between the first surface and the second surface;
• a lip extending outwardly from the panel, the lip including an outer surface and an inner surface;
• a pair of curved risers extending inwardly from the inner surface of the lip toward a center portion of the panel;
• a structural feature spanning between and contacting the pair of adjacent curved risers, the structural feature formed by a portion of the outer surface of the lip and a portion of the inner surface of the lip disposed in an at least immediately adjacent or contacting configuration;
• and
• an elongated tack-off spanning between and contacting the pair of curved risers, the elongated tack-off disposed between the generally planar panel and the structural feature, the elongated tack-off at least substantially preventing fluid communication between the generally planar panel and the structural feature, the elongated tack-off having a length at least three times greater than a height of a riser of the pair of curved risers.