Divide the total load according to how many supporting beams the roof will have.
Post and beam roof support.
In the 37 years we have been crafting timberframes we have designed and built hundreds of timberframes and timber trusses for homes restaurants and wineries.
Pacific post beam was founded in 1983 in sandpoint idaho as a custom builder of timber frame homes we relocated to san luis obispo in 1986.
Use the span tables below to determine allowable lengths of joists and rafters based on size and standard design 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.
While many like to use the smaller 4 x 4 posts they can tend to warp after they have been standing under the weight for several seasons.
And cdx fir plywood.
Measure the distance between the bottom of the porch roof and the top of the ledger beams of the porch.
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.
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.
Minimum sizes of posts and beams are set by engineering requirements and are strictly governed by local building codes.
Typically 2x12 spruce rafters 2 o c.
The smallest beams for patio covers are typically 4 by 6.
Continuous posts from the roof to the footing transfers the roof load to the ground rather than the deck this only makes sense and then the deck itself should be supported on a beam by separate posts.
Common post spacing while your beam size ultimately depends on design factors such as whether you include a covered roof structure or open lattice strips a familiarity with conventional beam spans gives you an idea of how far apart you can space your posts.
Once that s done and the support strapping is reinstalled on all gas electric plumbing and heating lines you ll have the satisfaction of completing a job that will last for the life of the house.
You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths.
The main structural members of patio and deck overheads are posts or columns and beams which run from post to post or from post to ledger.
This is an economical roof system with beautiful exposed support beams.
If there is also a beam in the middle of the roof divide the total load by three.
Join the support beam and wood load bearing post by toenailing them together and attaching two metal t braces to opposite sides of the beam with galvanized 10d box nails.