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.

Then there are wooden beams that are evenly spaced over the frame to create the roof. A 4 by 10 can usually span up to 12 feet between posts. The difference comes in with the type and installation of the beams. Strength given in the nds and wood structural panel design properties given in the apa pds.

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. The smallest beams for patio covers are typically 4 by 6. You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths. Divide the total load according to how many supporting beams the roof will have.

A louvered patio roof is similar to a pergola. Both have posts or columns that support a frame. If you move up to 4 by 8 you re usually allowed to span up to 10 feet between posts. 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.

Roof cover 1 2 plywood shuttering 1 5 psf roof framing 3 5 psf. 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. If there is also a beam in the middle of the roof divide the total load by three. Use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads.

In general the maximum span for a 4 by 6 beam is 6 feet between 4 by 4 posts. Timber beam design seismic forces wind forces floor shearwall diagram lateral loads. An essential part of planning a patio roof or gazebo project is determining the number size and spacing of rafters beams and posts according to the loads they will carry.