There's not quite enough information here to give a definitive answer, but for decks, a rule of thumb is when supporting joists that span 12 feet, a double ply beam can span in feet a value equal to its depth in inches. Thus, a double 2x12 beam could span 12 feet - with 20' beams, posts at 10' might look the best.May 19, 2015
What size beams to use for a pergola?
Most builders use a minimum of 2×8 for the upper framing members, and that's for a small pergola. On this pergola, the builder Ricky Chavez used 2×12 for the girders, 2×10 for the rafters, and 2×4 for a layer of decorative purlins fastened atop the rafters. Setting the posts square and plumb is a two-man job.
How big of a beam do I need to span 20 feet?
For 20 foot span, size of beam for 2-3 storey residential building, using thumb rule,1 foot (span of the beam) = 1inch (depth of beam), is about 12″×18″ in which beam width is 12″ and beam depth is 18″ providing with 2nos of 12mm bar at top, 2nos of 16mm bar at bottom and 2nos of 12mm crank bar of Fe500 with stirrup T8 ...
What size timbers do I need for a pergola?
To adequately support the lumber overhead as well as give the pergola a sturdy look, you'll probably need to use 6×6 for the support posts. For a very small pergola with only 4 to 6 feet between posts, 4×4 supports will work.
What size should pergola beams be?
Beams – 2×8 or larger, depending on size of the pergola. There is one double-beam on each side of the pergola. The beams will hang out approx 12 inches past the edge of the post and will be the support for the rafters. Rafters – 2×6 or 2×8 depending on the size of the pergola.
How far can pergola beams span?
There's not quite enough information here to give a definitive answer, but for decks, a rule of thumb is when supporting joists that span 12 feet, a double ply beam can span in feet a value equal to its depth in inches. Thus, a double 2x12 beam could span 12 feet - with 20' beams, posts at 10' might look the best.May 19, 2015
What size post should I use for a pergola?
A standard pergola will most often use 6 x 6 inch posts for support. A very small pergola may use 4 x 4 inch posts as long as it has less than 4 to 6 feet between posts. As a general rule of thumb the depth of hole you use for your posts should be approximately 1/4 of the height of your post.
How far can you span a pergola beam?
The key thing to remember when it comes to determining pergola rafter spacing is that you cannot go more than 16 inches from center-to-center between rafters.Jan 11, 2018