A redwood 4x6 beam should span no more than 6 between supporting posts.
Making a triple deck beam.
The two beams you can make out of 2 by 10 dimensional lumber are double beams and built up beams.
One is 27 and a half feet the other one is 31 feet.
Deck builders can now refer to section r507 6 deck beams and table r507 6 deck beam span lengths to determine the size of 2 ply and 3 ply built up beams made from 2 6 through 2 12 lumber.
Sizing deck beams got a lot easier with the publication of the 2015 international residential code.
The beams will be three ply pressure treated sp number two 2 by 12s using 12 foot long lumber cut to fit the distances between the supporting posts.
A 2x10 beam should use a minimum of 4 3 nails fastened in a vertical pattern from both sides of the beam every 16 on center.
A 2 2x10 can span 10 feet and so on.
A system of key connections throughout the deck framing also known as a continuous load path is essential to building a safe code compliant deck.
We describe building the beam out of 2x lumber in four easy to follow steps.
As a non engineer i always err on the cautious side and over build so i ve always added a strip of plywood.
The article concludes with a description of different methods used to make a secure structural connection between posts and.
Beams are an essential part of a deck s support system so if you re building your own deck you want to make sure these elements are as sturdy and long lasting as possible many older decks were built using massive timbers such as 4x6s or 4x8s for beams which support the underside of the deck horizontally.
A double beam is simply two lengths of lumber that sandwich the top of a beam.
I m building a ground level deck maximum 24 inches above the ground it s l shaped and it ll have two long beams.
When supporting joists that span 12 feet with no overhang beyond the beam a double ply beam can span in feet a value equal to its depth in inches.
Built up beams are boards nailed together.
When this system of connections is made properly loads are transferred throughout the deck s frame and into the ground and or the adjacent structure to which the deck is connected.
The numbers in gray indicate the distance between the support posts.
Obviously the larger the beam the greater the distance it can span between posts.
How to build install a built up structural beam for decks porches simliar structures.
Whether you are building a load bearing support beam for your wall or a deck beam you probably wondered about adding a 1 2 plywood strip in between 2x lumber.
Dimensional lumber deck beam span chart.
Refer to the deck beam span table below to assist in determining the maximum span of a given beam between posts.
How to nail a deck beam when securing 2 or more dimensional wood boards together to form a beam you will need to use the proper number and size nails to create a solid member.
