Roof Addition Framing
Adding a roof to a porch requires creating a framed roof area and attaching it to the existing house. The most common attachment locations are along a wall surface and the roof's fascia board.
To attach roof joists to a wall, use a horizontal support board, called a ledger, attached on the wall surface with joist hangers to hold the joists. Attach a second ledger atop posts on the outside edge of the porch to create the exterior frame.
Footings and Flooring
If a patio roof addition projects beyond the existing porch surface, builders must construct footings to support the roof addition posts or wall framing. Although local building codes specify acceptable footing types, common options include poured footings and precast concrete piers.
A wide variety of flooring materials are suitable for covered porch floors. Interior floor coverings are suitable for enclosed, covered porches.
Homeowners should use outdoor flooring materials for open-air or partially exposed porches, such as natural stone tile or decking lumber.
While many homeowners prefer to cover a porch roof addition with roofing materials that match their home's existing roof, all types of roof covering materials are acceptable for porch and patio covers. Popular options include asphalt roofing products, such as shingles and rolled roofing and rigid roofing panels.
Rigid roofing panels are available in both metal and plastic. Plastic roofing panels are clear, translucent or opaque.
Clear and translucent panels allow light to enter a porch from above, providing a sunroom effect.
Enclosed vs. Open Air
The primary design decision is a choice between an enclosed and an open-air porch. Although you can easily enclose an open-air porch later on, building the entire addition at once might save money and effort.
Homeowners may fill an enclosed porch's openings only with screens or with windows and screens. Enclosure with windows and insulated walls transforms a covered porch into a sunroom suitable for winter use.
Alternatively, open-air porches offer more comfort than enclosed porches in hot and humid climates.