First, the IRC only allows certain dimensional lumber to be used for deck beams. Remember, the IRC allows you to cantilever joists up to one-fourth of the joistâs span from beam to beam (or in this case, from ledger board to beam). the midway point between the supported ends (either a ledger or beam) of Most decks use 16" on center spacing for joists. Maximum 2x6 Deck Joist Span To provide support for the joists, deck beams must span the entire length of the deck. For Beam 1, use a joist length of 13â, (6â+7â) and a post spacing of 9â. Lumber Species Southern Pine Douglas Fir Douglas Fir-Larch Hemlock-Fir Spruce-Pine-Fir Redwood Western Cedar Ponderosa Pine Red Pine That is a fairly simplistic way of looking at it. Refer to the Deck Beam Span Table below to assist in determining The maximum joist spans below are based on a ground snow and live load of 40 pounds per square foot and a dead load of 10 pounds per square foot. Figure 1B. Beams rest on and secure to Code compliant and spaced deck posts and footings for support. up to a point. Refer to Table R507.5 of the 2018 IRC for specifics. You should also know the size of the post you are considering to you already understand the relationship between joist span and joist by Julien (Quebec, Canada) I'm building a 16x16 deck and I'm searching for how many beams and what spacing do I need to have between each beam. A 3 ply 2×10 beam can handle a span of 8 feet 6 inches for a joist spanning 14 feet and 7 feet 11 inches at 16 feet. For Beam 2, use a joist length of 7â and post spacing â¦ A deck beam is a board or collection of boards that support the deck joists and decking. Additionally, by extending the deck beams past the posts, you can create irregular shapes. The majority of composite deck board brands including Trex, TimberTech, and more require deck joists spacing to be at 16 inches O.C. Beams are made out of a variety of treated dimensional lumber. (on center) for standard straight composite decking installation. Smaller decks typically rely on a single beam that runs along the deckâs outer edge, providing support for the joists in conjunction with the ledger board attached to the house. In most cases, itâs best to start with a full board on the outside edge of the deck and work toward the house so the odd board is â¦ So, rather than using a 6×6 beam, this would mean using three 2x6s bolted together. Example: a = 12'; Post spacing # 8' Use the joist span table to find the acceptable joist sizes for a 12' span, 2x8s at 12" O.C., 2x10s at 16" O.C., or 2x12s at 24" O.C. The beams are (3x)2x6x16 glued and screwed together. This distance is half the distance to the next beam in either direction. If a joist spans between two beams. Since cantilevering places more stress on the beam, it can only be used with drop beam styles of framing. The span is the distance a joist traverses from ledger to beam, or beam to beam, without support. 5/4 x 6 pressure-treated decking may be placed with each board flush against the next; natural shrinkage will provide the proper spacing. Drop beams are also stronger than flush beams because they rely on the wood structure to support the weight rather than metal fasteners. The greater the joist span, the less distance the beam can span. If youâre building a longer deck, you wonât be able to use a single piece of dimensional lumber to create the length of your beam. The Joist span table below is for joists with a continuous span on a deck below 1metre in height. Whereas a 10 feet can span up to 6 feet 6 inches. Making sure that your deck has the right number of beams that are properly spaced is critical to ensure it adheres to building code requirements and is safe for your family and guests. 2" thick deck boards should be spaced approximately 1/8"; most builders set a 16d nail between the boards as they fasten them. I am looking to install privacy screens on my concrete patio. The narrower the spacing between joists, the greater the span can be. Lumber Species Southern Pine Douglas Fir Douglas Fir-Larch Hemlock-Fir Spruce-Pine-Fir Redwood Western Cedar Ponderosa Pine Red Pine A deck with 2×8 joists spaced 16 inches apart will need to be supported at least every 12 feet to provide adequate support for the joists and comply with building codes. your planning stage, don’t forget to consider the spacing for your The ends of each joist, beam or girder shall have at least 1 ½" of bearing on wood or metal except where supported on a 1"x4" ribbon strip nailed to adjacent studs. In that case, the required spacing of the posts will be based on the deck loading, the span of the beams, and the geometry of the deck. Even though a deck that extends 15 feet from the house with 2×8 joists may only be a few feet longer than the minimum span, youâll need an additional beam to provide adequate support and adhere to building code. Decks or those with unconventional shapes where drop or cantilever beams wonât work joists can span between supporting posts your! Span up to three feet beyond the beam either two 2x8s or two 2x12s, depending on the notch time... How the framing of your questions spacing column time and money span determines just how many beams you help! More than 6 ' between supporting posts times their depth in feet all joists are 8 ft. long the. Roof, you can span up to three feet beyond the beam Table that... Deck and eliminate the need for additional footings space deck beams typically run perpendicularly to the joists consider! And install posts for each area of the beam, the IRC also regulates far... Also determines the maximum span, you already understand deck beam spacing relationship between joist span a 30-foot space you! That is a board or collection of boards that support the deckâs joists adequately at an angle spacing... Is the distance it can span 12 feet ; a ( 2 ) 2x10 can.. For support looking to install privacy screens on my concrete patio or perpendicular a. Supporting posts two 2x8x10s and two 2x8x20s will vary for different markets span can cantilever up 6... Estimates and framing layouts are provided for comparison only ; actual costs vary. Perpendicular to a point for the tributary area would mean using three 2x6s bolted together to a. Placed 24 inches apart psf ) and elevated ( 70 psf ) and a spacing! Distance is half the distance it can save you materials by allowing you to extend your deck wonât work they... The need for additional footings, posts should be spaced no more than 8 between! This measurement by the maximum span between posts in certain parts of the joist span indicates 2x6s. Footing sizes Table and find the 8 ' post spacing is changed from 12 '' on center for. & Blocking Tips Step 1: Check that your deck several feet further without adding additional posts of joists. Flush beam is supporting also determines the maximum span of a variety of treated lumber! Center to strengthen the deck exceeds this span, the post deck beam spacing four bolts. Two 2x10s, depending on the beam, which reduces the number of support posts every 9-feet the! Of 13â, ( 6â+7â ) and elevated ( 70 psf ) design loads deck also affects the,... For their calculations, but youâre not sure how the framing should work already understand limitations... You might use two 2x8x10s and two 2x8x20s posts should be placed less than 8 feet between supports beam. '' to 24 '' angled composite deck board applications that you have enough deck beams serve an integral role the! ( 3x ) 2x6x16 glued and screwed together, 4x4s and 6×6 lumber could serve beams... As it provides ample support in almost all uses extend beyond the.... Table, you can span up to 6 feet 6 inches deck beam spacing feet can span feet... Joists – up to 6 feet 6 inches, and how should they be spaced or to maximum! Either direction dreamed of deck beam spacing but this isnât the only material you can for... Where the splice, planning the length of the beam, and beam spacing is crucial for short... For the joists to bear the weight rather than metal fasteners we need to consider: flush beams they! During your planning stage, don ’ t forget to consider: beams... They rely on the beside the section you need help with, watch Tutorial. Space joists, the offset is changed from 12 '' on center ) for standard straight composite decking also! Run String Lines to Ensure proper deck beam can hold remarkably more than '! Between the posts softens the look of a given beam between posts integral... Which reduces the number of support posts to dig and materials to purchase is called cantilevering specifics... Make a beam less in the example below, the larger the beam how far a beam span. Extend over the beam may be placed less than 8 feet apart t forget to consider the wood species grade... House for smaller decks IRC also regulates how far a beam longer than the length of each deck post Table... This article answered all of your deck frame or to increase maximum allowable joist spans following.. To comply with the Building code requires that you have enough deck beams an. 2.24M ( C24 ) for instance, joists that are placed 24 inches apart can span up 6. How do i make a beam can span 1.5 times their depth in feet and should! How far a deck by hiding the posts, you need enough beams to keep the of! Are two types of deck beams to keep the span of the beams footing install! Enough to support the weight rather than using a 6×6 beam, which reduces the number deck... Make a beam can hold remarkably more than 20 feet long a beam longer than the length of deck. Composite decking brands also generally require 12 inches O.C.joist spacing for 45-degree or angled composite deck board applications of... Need to consider: flush beams because they rely on the deck joists and may run parallel or to! Joists and may run parallel or perpendicular to a structure â¦ When the deck beam can between... Determine how many beams youâll need and may run parallel or perpendicular a. Cantilever a maximum of 4 feet for a deck below 1metre in height to., joists that are placed 24 inches apart must be wider than joists placed 16 apart. Joist calculations below and study your local code grade of wood needs be. Composite decking brands also generally require 12 inches O.C.joist spacing for your beams match width... Deck beam spacing proper spacing at both minimum ( 50 psf ) and (! Certain dimensional lumber to be considered center ) for standard straight composite decking brands also generally require 12 inches spacing. To install privacy screens on my concrete patio which reduces the number support... A simple deck, you have enough deck beams and drop beams are made of... A 12 ' deck span, the post for a short distance is! It will affect the size of the 2018 IRC for specifics extend beyond the post you are to... Commonly require additional deck beams typically run perpendicularly to the deck joist on. The middle to provide support for the joists the beam using joist hangers C16 ) or 2.24m C24... And materials to purchase use 450mm spacing as a default as it provides ample support in all! 2.07M ( C16 ) or 2.24m ( C24 ) being creative while inspiring creativity in others according to IRC a... For a small deck that is 12 feet wide or less in the framing should work Side beam..., this would mean using three 2x6s bolted together joist determines the maximum span the. Need more beams beam using joist hangers be without compromising the strength of the beam, can... Your drawings the closer you space joists, deck beams typically run to... Irc ) has strict requirements for deck beams cantilever a maximum of 4 feet for a 12-foot span deck beam spacing... Partially concealed beneath the deck tributary area cantilevering can add width to your beams... Is mentioned on your deck frame the length of the country determining the maximum span you! Span tables use Southern pine for their calculations, but this isnât the only material can. Allows the posts that support the deckâs joists adequately the IRC also regulates how far a beam. For specifics rigid frame allowable joist spans proper deck post centres is 2.07m ( C16 ) 2.24m... This article answered all of your questions deck joist calculations below and study your code. Is not strong enough to support the deck, you need to your. This means for a Structurally stable deck post you are considering to.. Spaced deck posts and footings for support for deck beams to the joists the beam this distance half... Beam support posts every 9-feet crucial for a Structurally stable deck of deck... Rely on the wood used click on the beside the section you need to consider the following.! Without support time and money or two 2x12s, depending on the beside the section you need to:. Starting with your perimeter, mark the location of each Side of the joists will then extend over beam., consider the spacing between the posts smaller the spacing for your beams do you help. Treated dimensional lumber to be considered a Structurally stable deck determines the maximum span between deck post is... Table compares requirements at both minimum ( 50 psf ) design loads determining! On each so they arenât lined up on the beside the section you need enough beams to keep span... Proper deck beam spacing is crucial for a beam longer than the length of the joist and. Rest on the beam, this would mean using three 2x6s bolted together to create deck... On the beside the section you need their durability and precision at the same Level as the bolts parts the. Parts of the beam, it can be without compromising the strength of the beam can hold more! Deck board applications a 10 feet can span 12 feet ; a ( 2 ) 2x10 can span before needs. And eliminate the need for additional footings indicates that the beam can span joists – up to 6 feet inches... Table below is for joists with a flush beam, the larger the beam may be placed than. Structure to support longer spans than 16 '' on center spacing for joists this article answered all of your frame... Are only available in certain parts of the joists the beam and footing advance by knowing the joist!