CPC E04D 13/076 (2013.01) | 17 Claims |
1. A device comprising:
a first support member having a first support member length and comprising one or more stress riser formations;
a second support member spaced at least substantially equidistant from the first support member along at least a majority of the first support member length;
a first plurality of spaced drainage ribs extending from the first support member towards the second support member;
a second plurality of spaced drainage ribs extending from the second support member towards the first support member; and
a third plurality of spaced drainage ribs extending between and coupled to the first plurality of drainage ribs and the second plurality of drainage ribs,
wherein the third plurality of drainage ribs is longitudinally offset from at least one of the first plurality of drainage ribs and the second plurality of drainage ribs.
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