By Mark Zeh
The owners of a stone manor-style home in upstate New York were seeking to transform their patio, situated in a large garden, into a place that could be enjoyed and used for entertainment year-round. Key requirements were a large, retractable cover that would protect against sun glare, heat, UV and rain. The cover needed to be fully retractable to avoid snow loads, and so that sunlight would shine into the house in the winter.
The solution: a three-span retractable waterproof patio cover. The support structure is comprised of four inverted L-shaped elements constructed of rectangular-section aluminum extrusions bolted together using cast junction pieces. A horizontal element ties the four L’s together along the edge furthest from the house. This span also serves as a water-catchment: captured moisture flows from the horizontal element into the two outermost legs, then drains out into the flower beds through small holes in the base of the legs. The aluminum components are all powder-coated a dark brown for superior durability, and all fasteners are stainless steel (INOX, either AISI 370IL or 430).
Due to the uneven nature of the stone outer wall of the house, the horizontal supports are fastened to a pressure-treated header board mounted to the outer wall of the house above the patio. Minimum clearance at the entrance is 345.4 cm (11 ft.-4 in.). The base of the L’s are fastened to individual concrete footers located just outside the edge of the patio paving. The height of the top edge of the framing at the outmost edge is 243.8 cm (8 ft.). The structure’s purlins project 914.4 cm (30 ft.) from the wall of the house and the center-to-center distance between the furthest spans is 944.9 cm (31 ft.).
The frame supports aluminum guides that support the drive mechanism and retractable fabric cover made of a single piece of PVC-covered polyester in a light-transmissive yellow/ochre color (chosen because it is waterproof, dust resistant, partially light-transmissive, fire-retardant and durable). The fabric weighs 480 gm/sq. m (14.2 oz/sq. yd.) and has an expected lifespan of 15 years.
A retractable patio cover system was chosen over the more commonly-seen folding-arm systems due to the desired large extended span and the advantage that a single piece of fabric can be used to form the cover for awnings with extensions over 487.7 cm (16 ft.).
This installation uses a belt-driven, single-motor system with the motor housed in a box at the rear of the patio cover. In addition, the retracted cover is sheltered from rain, debris, leaves and snow accumulation by a hood with end caps. For convenience, it is operated by both a remote control and a wall switch inside the house.