California Cradle Arch

Appearing at first site to be somewhat conventional, this patio cover has many unconventional features. First, the dual joists running from the back wall are heavier and more numerous than the dual supporting beam which they intersect. This is made possible by supporting the dual beam directly over the columns under the end joists and supporting the interior dual joists with arched kneebraces.

The arches are then continued beyond the support points along a "French Curve" trajectory and tied together with a "cradle" in the form of a "Kings-man ax". In this cookie cutter space is hung a polished-brass cut-glass lantern.

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The canopy appears to be the customary wooden 2 x 4 skip-lath but the 2 x 4's are actually hollow rectangular PVC (polyvinylchloride plastic) tubing with PVC end-caps. This decreases the load that is being transmitted through the arched kneebraces to the center of the post by 70%.

The canopy itself is rather high by conventional standards: 11' , two feet above the normal 9'. The extra height allows the canopy to clear the fixed transit windows on the rear wall.

Because of the added height and the necessity to use kneebraces, the columns are segmented into two sections. Square on the top half and round on the bottom half, these ornamental sleeves hide a continuous 8 x 8 post that runs from base to beam. This segmentation mitigates the long stretch from ground to canopy.

Even though there are significant engineering considerations involved, the structural elements are subordinate and supportive of the design aspects: To be attractive, architectural considerations should camouflage engineering ones. That principle is applied throughout this structure where not a single fastener (neither nail, screw, bracket, bolt, washer, nut, nor glue-line) is visible anywhere.