Patio Roof Structural Beam Spacing

Before i began designing the structure of my new patio cover i expanded the existing 10 x 10 patio slab by pouring another 10 x 10 slab next to it making it roughly 10 x 20.

Patio roof structural beam spacing.

You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths. Louvered patio roof ideas. The smallest beams for patio covers are typically 4 by 6. Beams can be solid lumber or be built from lengths of 2 by lumber nailed together with 1 2 inch pressure treated plywood spacers in between this forms a 3 1 2 inch thick beam that is equal to the width of a 4 by post.

Pergola s are thicker mounted on the shorter width and do not move. Both have posts or columns that support a frame. Maximum rafter spans for a patio roof in areas with mild climates patio roofs are generally designed for loads of 30 psf pounds per square foot. A 4 by 10 can usually span up to 12 feet between posts.

A louvered patio roof is similar to a pergola. Since i was planning to attach my patio cover to the existing roof overhang of my home i ensured that it was capable of carrying half of the weight of the new patio cover roof. The difference comes in with the type and installation of the beams. Timber beam design seismic forces wind forces floor shearwall diagram lateral loads.

Divide the total load according to how many supporting beams the roof will have. Roof cover 1 2 plywood shuttering 1 5 psf roof framing 3 5 psf. Strength given in the nds and wood structural panel design properties given in the apa pds. In general the maximum span for a 4 by 6 beam is 6 feet between 4 by 4 posts.

If you move up to 4 by 8 you re usually allowed to span up to 10 feet between posts. If one side of the roof is supported by the house and the other side is supported by the beam divide the total load by two as the beam is only supporting half of the roof. Use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads.