When summer temperatures soar, the backyard is definitely the place to be. But if your patio or deck bakes in the sun more than you’d like, it might be time to consider a patio cover to get yourself some welcome shade.
Patio covers range from the simple to the ornate. They can be large or small, painted or natural wood, and covered with anything from wood slats to solid roofing. But remember that when summer’s sun is replaced with the ravages of winter your patio cover needs to stand up to the elements, so whatever your design, make sure it’s built correctly.
For most yards, patio covers are simply a shed roof with a moderate slope that extends off the rear or side of the house. Most designs consist of a ledger — a horizontal board to which joists or rafters are attached — against the house with a series of rafters extending from the ledger to a beam some distance out from the house. The beam is supported by posts, and the rafters are then covered with the roofing material.
The first temptation with a patio cover is to skip the ledger and attach the rafters directly to the fascia, but that can be a recipe for disaster. Roof fascias are primarily decorative, and are designed to carry little more than their own weight. Placing the load of a patio cover onto a board that was never intended to carry it can easily result in the fascia being torn loose from the house, especially in areas with winter snows.
Instead, begin with a ledger or a beam that is placed against the house itself, and is secured to the wall framing. The fasteners that secure the ledger in place must penetrate all the way through the siding and into the wall studs in order to provide adequate support. In some jurisdictions with heavy snow loads, the ledger must also have vertical supports under it that extend all the way down to piers or other adequate load supports.
At the other end is a set of posts that support a beam. The posts can be set into holes in the ground and secured with concrete, or, more commonly, they are placed on poured concrete pier pads. When the concrete is poured, a steel post base anchor is installed in the proper location, and the post is then secured into the anchor. After cutting the posts to the proper length to provide slope for the rafters, the beams are installed on top of the posts and secured with steel connection caps or other structural connectors (simple toenailing does not provide an adequate connection).
The rafters are added next. Depending on the design and the allowable codes, the rafters may be attached to the ledger using metal joist hangers, or they may sit on top of the ledger and be secured to it with metal ties. Metal ties are also used to secure the rafters to the beam at the other end, and solid blocking is typically required between the rafters over the beam, over the ledger, and at specific locations along the rafters’ length.
How you cover the basic framework depends on both aesthetics and function. For a patio cover that breaks up the sun and provides intermittent shade, you might want to consider spaced wooden slats. These can be 2-by-2s, 2-by-4s or other material, spaced from one to several inches apart. The slats can even be ripped at an angle along the bottom, which in turn will tip the slats to block the sun at specific times of the day. A grid of slats installed at right angles to one another will provide even more shade and architectural interest.
For a more solid cover that still provides plenty of light, you might want to consider a covering of corrugated fiberglass panels. Precut wooden strips that match the high and low corrugations of the panels — available wherever the panels are sold — are installed first. They are nailed over the tops of the joists and perpendicular to them, and provide solid support for the roofing panels.
Corrugated fiberglass panels are available in translucent and solid colors to suit your design and your sun-blocking requirements, and you can also use a combination of the two for both light and shade. If you intend to paint your patio cover, you’ll find the task much easier if you paint everything — including the corrugated wooden molding strips, if desired — prior to installing the roofing panels.
For solid shade, or to provide rain protection, a solid roof might be the answer. This can be made from plywood sheathing covered with singles to match your existing roof, or done with metal roofing panels or other materials.
Remember that patio covers are a structural element of your house. They are also big and subject to a lot of wind and snow loads, and can be highly dangerous if they are poorly designed or constructed. As such, they are subject to the provisions of the building codes, and also require a permit for their construction. Before beginning any patio cover project, be sure to consult with your local building department for complete requirements on lumber sizes, pier dimensions, ledger and rafter connections, and other important structural details.
Remodeling and repair questions? E-mail Paul at firstname.lastname@example.org.