Wind Loads on Patio Covers

A common characteristic of North American low-rise residential buildings is the patio, a very active and eventful part of family's living space, with a number of activities to take place on it. For most home owners and unfortunately for many retailers, the patio cover is assumed to be a structure of minor importance which can be constructed without any special design. Patio covers are structures that have not fully been examined and evaluated by the present building codes. Very few studies have been carried out and it is questionable whether the performance of these structures is underestimated or, in the contrary, these are over-designed due to the lack of appropriate knowledge. Like every engineering problem, the dilemma vacillates between safety and cost. The current study presents the methodology and findings of a set of wind tunnel tests on a building model with a patio cover attached to it. Both the testing procedure and the data analysis are discussed and detailed results are presented. Although these structures are relatively simple, they occasionally form part of an existing building, subjected to same loads and accommodating the same number of people — or even more — as that building. Patio covers are often treated as a subsection of canopies. Sometimes they are even assumed to be an extension of the roof. In most cases though, patio covers cannot fall under any of the above categories. Canopies are used as covers and are not usually surrounded by walls. The specifications, use and geometry of canopy roofs though, defers significantly of those of patio covers. Moreover, patio covers are often at a lower level than that of the roof, thus they cannot be treated as roof extensions or overhangs. The only wind codes that clearly refer to attached patio covers are the International Building Code [IBC 2000], the International Residential Code [IRC 2000] and the Australian Wind Standard [AS/NZS 1170.2:2002]. Various other national building codes include wind provisions for canopy roofs or open buildings.