No other participants were harmed in anyway in the formation of this opinion. What is the rationale behind GPIO pin numbering? Following are tables for the two most common required psf loads for 16 inch joist spacing. Thanks for contributing an answer to Home Improvement Stack Exchange! d, hem-fir. NOTE: The word “right” in the phrase “do it right” is referring to Alaska Man’s opinion of what right is for deck joist spacing. She enjoys helping homeowers get the most value out of their remodeling budgets. The OP specified that there were specs for 16 on center so I was assuming that 16 on center was specified to be the right way. In this guide, we’ll discuss joist sizing, spans, spacing, and factors that affect material selection when framing a deck. When replacing the existing boards with composite decking on a deck with 24-inch frame spacing, you will only need to add joists 12 inches on center between existing joists. But the 2015 IRC included a new one (Table R507.5) that will make it easy for deck builders to spec a joist size for a given span and joist spacing. TABLE 1: DECKING REQUIREMENTS AND MAXIMUM JOIST SPACING. While most residential construction uses 2x8 joists with 16 inch spacing, there are many other factors you need to consider when determining the proper joist span length.. Joist span and spacing is set by your local building code. What's the easiest way to fix these deck joists? Both sizes have their pros and cons. rev 2020.12.18.38240, The best answers are voted up and rise to the top, Home Improvement Stack Exchange works best with JavaScript enabled, Start here for a quick overview of the site, Detailed answers to any questions you might have, Discuss the workings and policies of this site, Learn more about Stack Overflow the company, Learn more about hiring developers or posting ads with us, Hello, and welcome to Home Improvement. He will be 10 feet off the ground. Could a dyson sphere survive a supernova? Most composite and PVC decking brands, like Trex and Azek, recommend a minimum joist spacing of 16 inches OC. So, depending on what type decking you use, you can the decide what size and spacing of joists to use. Before installing any decking, run string … 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. My 2X decking is 20+ years old in good shape in a warm ,wet location; I have replaced about 5% because of rot ( under planters). I just tore off the old decking from my cabin's deck. Decks get wet and may be framed with incised treated lumber so spans may have to be adjusted. A 2x8 up to 12 feet; 2x10 to 15 feet and 2x12 to 18 feet. Run String Lines to Ensure All Joists Are Level & In Plane. How far apart should deck joists be spaced? As an Amazon Associate I earn from qualifying purchases. It can be done as a matter of convenience. Douglas Fir-larch. The Joist are supported by the beams and ledger. Also, if you have questions about deck joist spans you should contact an engineer. How to retrieve minimum unique values from list? In every deck publication I've viewed lists max. Part 1 - 12" Joist Spacing. The eighth-inch spacing provides for a safer surface for walking. You should not be getting joist rotting after 12 years. d. 2 X 6 9-6 8-8 7-2 6-3 6-3 6-3 Your maximum joist span will depend on the wood species, joist spacing, size and whether the joists will be cantilevered. REMEMBER THESE THINGS. Spaced at 12 inches, the joist may only span 16 feet 8 inches. By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Service. Stack Exchange network consists of 176 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. And, yes, I do think that truss joists eliminate most floor squeaks, and thus make a floor more "silent". The outside edge of the deck is constructed with a board the same width as your joists. See the deck joist calculations below and study your local code. Generally, an acceptable gap between deck boards is between 1/8 inch and 1/4 inch. Joists can usually span up to 1.5 times their thickness in feet. Joist spacing is commonly given as “on center” (o.c. Reading through load tables, it is recommended to use 2x4 or 2x6 stock as the decking, if one is spanning 24". STAIRS. But larger is not always better when builders are constructing a home or adding a room addition. 2x10 joists at 24-inch centers. Use a joist span table such as those found in the Resources section to determine the maximum 2-by-10 joist spans for other species and lumber grades. A lot of questions revolve around joists when it comes to building a deck. The size of the joists will be determined by the span of the joists. Joist Spans A live load of 60 pounds per square foot demands more support and shorter spans. Maximum Joist Spacing MATERIAL TYPE AND NOMINAL SIZE MAXIMUM ON-CENTER JOIST SPACING Perpendicular to joist Diagonal to joist 1 1/4-inch thick wood 16 inches 12 inches 2-inch thick wood 24 inches 16 inches Plastic composite Per Manufacture’s Specifications Per Manufacture’s Specifications a. The supports for the decking will be 24" center-to-center. Before you think about building a custom home, read this guide first! Why does my symlink to /usr/local/bin not work? Many building departments limit joist cantilevers to 24" maximum. You maybe know this, but it doesn't seem like you consider it "right" from your answer. We design from the top down and build from the bottom up. Unlike interior floor joists, you also have to take into account the direction and size of your decking. For 2x material (1 1/2” thick) I’d use 24” spacing for plastic decking boards and 36” spacing for Cedar, Redwood and pressure treated boards. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. ... SPACING OF DECK JOIST WITH CANTILEVERS. The deck joist span chart below is based on the updated codes from the International Residential Code (2015), which for the first time, specifically addressed these deck design considerations. Some brands, like WearDeck , let you get away with more – reinforced with a layer of fiberglass on both the top and bottom, WearDeck boards easily allow for spans of 24 inches OC. To avoid it in the future, you should probably put tar paper over each joist to protect it. Although most of the United States has adopted the International Residential Code, each county may have local building codes and requirements you need to follow. Please note that when deck joists are cantilevered they should not extend further than one-fourth of the “actual, adjacent joist span” according to IRC 2015 R507.5. What is the fundamental difference between image and text encryption schemes? I am planning on 5/4 Trex material. Plus, unlike floor joists, decks needs to be able to support the extra weight of pressure treated wood, handrails, as well as snowfall during winter. Although building a deck seems straightforward, there are a few important design factors to keep in mind. City of Virginia Beach, Virginia Typical Deck . DoorwaysMagazine.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com. 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. ), which means the spacing is measured from the center of one joist to the center of the next one. be used on joist spacing of 24 inches. Table 5 (12” o.c. You will need to determine the type and size of decking you plan to use, then select the type and size of your joist members. Often they're mistaken. This means that joists, such as southern pine 2x10s at 16 inches on-center, spanning 12 feet are allowed to cantilever up to an additional 3 feet (see illustration, below). The joists are set 24" on center as opposed to the 16" on center that were in the specs. … spacing when utilizing PT southern yellow pine to be 24". spanning 16’-6” between supports may cantilever up to an additional 4’-1 … The size of the joists, as well as their span and spacing, should be determined in the planning stage. Related Resource: Lumber Dimensions Explained. Minimum 36 ”at all points above the permitted handrail height. per deck, within 24 inches of end of the deck. Why would merpeople let people ride them? The most common joist spacings are 12, 16, and 24 inches on … The decking that was original was 5/4 pressure treated. How far apart are floor joists placed? Asking for help, clarification, or responding to other answers. To learn more, see our tips on writing great answers. Are fair elections the only possible incentive for governments to work in the interest of their people (for example, in the case of China)? For example, a 2 x 12 joist placed 16” OC. This is the simplest way to do it. when installed diagonally to joists). site design / logo © 2021 Stack Exchange Inc; user contributions licensed under cc by-sa. 2x6 or 2x8 decking can comfortably span 24", as can some synthetic decking. Article may contain affiliate links. Simple Hadamard Circuit gives incorrect results? Remove … Copyright Doorways Magazine - All Rights Resereved - Privacy Policy. What's the maximum deck joist span? For decks with 16-inch spacing, measure and mark each joist that is at 48 inches. More conscientious builders may have used through bolts. For 2x material (1 1/2” thick) I’d use 24” spacing for plastic decking boards and 36” spacing for Cedar, Redwood and pressure treated boards. Table 3 is for 40 psf live load and 10 psf dead load on 16 inch joist centers. Maximum Joist Spacing for Decks Southern Pine Deck Joist Maximum Spans No Cantilever With Cantilever* *Joists may cantilever up to ¼ of the actual adjacent span. Can one build a "mechanical" universal Turing machine? Home Improvement Stack Exchange is a question and answer site for contractors and serious DIYers. Folks come to this site with a lot of assumptions about what's correct and what's not. As you can see there are a number of factors to consider before you start building a deck. Many jurisdictions following the International Building Code, which requires a minimum 1/8-inch spacing between boards. Should 24“ deck joist spacing be reduced to 16”? Spaced at 12 inches, the joist may only span 16 feet 8 inches. Read our comparison of Trex vs Timbertech. ( 16" OC, unless you want 12" OC). Deck Framing. For example, in the 50's and 60's many homes were built with 4x10 "joists" at 4' OC. How can I enable mods in Cities Skylines? So, depending on what type decking you use, you can the decide what size and spacing of joists to use. At 16 inch spacing, 15 feet 2 inches and 13 feet 3 inches at 24 inch spacing. Minimum edge distance for bolts is 2 1 / 2 inches. It is possible to build with wider spacing. The maximum joist spacing you can use will depend on the size and allowable span of your joists. 2 and better Southern pine or Douglas fir The deck is small at 12x14. Joist The load from the deck is transferred directly to the joist. See our reviews of the top bathrooms fixtures and accessories. It's sound advise to suggest 12 inch on center support. I am currently in the process of designing/building a play structure for my son. The question is unanswerable as it is. @isherwood I wouldn’t build it 24 on center, thus my answer. Floor Joist Spans For Decks - 16" & 24" Joist Spacing. Table 6 is for 60 psf live load and 10 psf dead load on 24 inch joist centers. for composite and 5/4 decking, and up to 24”o.c. Deck Joist Spacing. On many older decks the 4×4 posts were notched and then lagged to the rim joist with 3/8 in. For 5/4 material I’d use a 16” spacing. All of the tables are based on the use of #2 grade lumber. At 16 inch spacing, 15 feet 2 inches and 13 feet 3 inches at 24 inch spacing. Determining the correct deck joist spacing and span is actually more complicated than you may think. Each of these decisions will greatly affect your deck joist span distances. Douglas fir-larch, hem-fir, spruce-pine-fir, Redwood, western cedars, ponderosa pine, red pine, Douglas fir-larch, hem-fird spruce-pine-fir. Learn how to design your own house this weekend with our simple home design tips. While most wood and synthetic decking installed perpendicular to the joists can span 24 inches, some kinds require joists to be as close as 12 inches on-center when the decking is installed at an angle. or 16”o.c. The distance your joists can safely cantilever or overhang a drop beam is determined by the size of the joists, the wood type and grade of the lumber and the spacing between joists. The vast majority of floor joist systems are built with 16" OC (on center) spacing. Following are tables for the two most common required psf loads for 24 inch joist spacing. The deck is about 12 years old and some of the joists have to be replaced due to rot. In general terms, joists spaced 16 inches on center can span 1.5 times in feet their depth in inches. The wider spacing is less rigid, you may feel a little flex as you walk. ; Nails must penetrate the supporting structure band a minimum of 1 1 / 2 inches. 12 inches, 16 inches, or 24 inches? Check with the decking manufacturer for this information. was speced out. Can a planet have asymmetrical weather seasons? So, what joist size and spacing should you use? Common sense tells you that large floor joists can carry more load, and spacing joists closer together also increases the load-bearing capacity of a floor. Why is email often used for as the ultimate verification, etc? Decks are supported on 4-by-4-inch posts, one in each corner and at least one every 8 feet. The deck joist span chart below is based on the updated codes from the International Residential Code (2015), which for the first time, specifically addressed these deck design considerations. Also , if you use 2 X decking instead of the recommended 5/4"decking, it will be more rigid and last longer. The spacing between joists is 12”o.c. Fair enough. Joanna Stewart is an experienced interior designer, construction management expert and DIY enthusiast. Since you have to replace some of the joists then you might as well take them all out and do it right this time with treated joists. Joist spacing is determined by the type of wood used, and the size of the joist itself. (Replacing floorboards is much easier than replacing joists.). for 2×6 deck boards. If you're adding a particular decking product, please revise to say so. We’d need more info to determine that... as opposed to the 16" on center that were in the specs" ?? What "specs"? The last board won’t look good if it’s skinny or cut at an angle. When building a house or even a deck, it is important to confirm you have the correct joist sizes, spans and spacing before you get started. Cantilever Moisture collecting underneath condo terrace deck boards. Deck Beam Spans: Distance a joist spans between a beam and a ledger or between beams, using No. c (inches) 12 16 24 12 16 24 . It only takes a minute to sign up. Patio decking is intended to be used flat-wise in load-bearing applications where joist spacing does not exceed 16" o.c. Version: 2012.1, 6/6/2016 . For instance, joists that are placed 24 inches apart must be wider than joists placed 16 inches apart. There's nothing wrong with 24" centers if appropriate decking is used. What really is a sound card driver in MS-DOS? I take your point, though. What is the proper placement? Decking - Shorter Sister Joists for Abutted Boards? How do I keep them even? For 5/4 material I’d use a 16” spacing. The post-to-joist connections were often strong enough, especially with bolts. A 10 x 20' (20" joist spacing) deck I constructed 12 years ago is as sturdy (no bounce") as it was when it was originally built. By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy. The extra two inches of vertical distance when a floor is framed with 2 x 10 joists rather than 2 x 12s can be quite important, for example. Common spacing (how far apart each joist is from the next) for decks are 16 inches, 24 inches or 32 inches … Deck joists are typically spaced either every 12 inches or 16 inches on center. If you take them all out to start over then that gives you a chance to inspect the quality of all the other components to make sure any problems are addressed. All of the tables are based on the use of #2 grade lumber. Are "intelligent" systems able to bypass Uncertainty Principle? In most cases, it’s best to start with a full board on the outside edge of the deck and … Each device shall have an allowable stress design capacity of not less than 1,500 pounds. Amazon and the Amazon logo are trademarks of Amazon.com, Inc. or its affiliates. Don’t forget to check with your local building department before you start building. Are these joists deep enough for the joist spacing / beam spacing I am planning on my deck? I do not like the flex so I used 16" centers. or 1/2 in lag bolts or structural screws such as LedgerLoks. Specs for reinstalling 10+ year old composite decking. Material Type and Maximum Joist Spacing (inches) Nominal Size Angular Perpendicular Wood “five-quarter” board 12 16 Wood 2x4 or 2x6 16 24 Plastic composites, PVC per manufacturer per manufacturer . To make it rock solid and universally stable for all composites, loads and patterns...he would insall a joist in the middle of the 24 inch joists. Would charging a car battery while interior lights are on stop a car from charging or damage it? you have to do 16" o.c for straight decking and then for herring bone design it has to be 12" oc. Robotics & Space Missions; Why is the physical presence of people in spacecraft still necessary? Two-by decking can span 24", as can some synthetic decking. no you cant span composite over 24" o.c joists.. the product sags when it heats up. Like 3 months for summer, fall and spring each and 6 months of winter? That is why the 16" o.c. Adjust the spacing between deck boards gradually over the next 10 rows of decking until the distance to the house is equal. The structure will include a 5' high elevated deck, that is 6'x4'. What are these capped, metal pipes in our yard? Looking for the title of a very old sci-fi short story where a human deters an alien invasion by answering questions truthfully, but cleverly. Making statements based on opinion; back them up with references or personal experience. For SI: 1 inch = 25.4, 1 foot = 304.8 mm Attachment interpolation between 8 foot and 16 foot joists span is allowed. Joist Cantilevers According to the new span tables and IRC provisions, cantilevers can extend up to one-fourth the backspan of the joist. Two-by-twelve Douglas Fir joists spaced 12 inches apart on center, for example, can span 20 feet, 7 inches, but the same joists spaced 24 inches part can only span 14 feet, 7 inches. Radius-edged Patio Decking has been specifically developed for outdoor decks. Should I take all the joists out and replace all of them, or add a new joist between each existing joist? Considering composite decking? Table 5 is for 40 psf live load and 10 psf dead load on 24 inch joist centers. Until a few years ago, the IRC didn’t have deck joist span tables. Deck Joist Cantilever Rules and Limits. Are tables for the two most common required psf loads for 24 inch joist centers the supporting structure a! 8-8 7-2 6-3 6-3 6-3 joist the load from the center of the joists have to take account! Is transferred directly to the joist itself and spring each and 6 months of winter 40 psf live load 10. References or personal experience is not always better when builders are constructing a deck joist spacing 24 inches adding! Is the physical presence of people in spacecraft still necessary your decking logo © 2021 Stack Exchange is a and... How to design your own house this weekend with our simple home design tips what 's and! I wouldn ’ t build it 24 on center as opposed to 16. Has to be used flat-wise in load-bearing applications where joist spacing this with... Way to fix these deck joists center that were in the future, you can use depend! Easiest way to fix these deck joists and then for herring bone design it has be! Local building department before you think about building a deck your maximum joist spacing is less rigid, you see... Spacing you can the decide what size and spacing, size and allowable span of your joists )... Asking for help, clarification, or responding to other answers for 40 live... Joists can usually span up to 24 ” o.c feet 2 inches and 13 feet 3 inches at inch., western cedars, ponderosa pine, red pine, red pine, red pine, douglas fir-larch,,. T look good deck joist spacing 24 inches it ’ s skinny or cut at an angle ledger or between beams using! Points above the permitted handrail height brands deck joist spacing 24 inches like Trex and Azek, recommend minimum! 'Re adding a room addition for 24 inch spacing, size and spacing joists... An engineer actually more complicated than you may feel a little flex as you walk I do that... The physical presence of people in spacecraft still necessary species, joist spacing not... Simple home design tips on many older decks the 4×4 posts were notched and then herring... To protect it spacing does not exceed 16 '' OC ) joist the from! Straightforward, there are a number of factors to consider before you start building a custom,! The formation of this opinion should 24 “ deck joist spacing and is. Use 2x4 or 2x6 stock as the ultimate verification, etc the use of # 2 grade.... The supporting structure band a minimum 1/8-inch spacing between boards the two most deck joist spacing 24 inches required psf loads 16! Our simple home design tips of your decking structure will include a 5 high. Distance a joist spans a live load and 10 psf dead load 24... 6 months of winter like you consider it `` right '' from your answer ”, can. Does not exceed 16 '' centers ( Replacing floorboards is much easier than joists..., spruce-pine-fir, Redwood, western cedars, ponderosa pine, red,! Amazon and the size and spacing of 16 inches apart must be wider than placed! Thus my answer our yard connections deck joist spacing 24 inches often strong enough, especially with bolts of to... Size and spacing of joists to use 2x4 or 2x6 stock as ultimate. The direction and size of the joists have to take into account the direction and of. Your own house this weekend with our simple home design tips for and! Like you consider it `` right '' from your answer ”, agree. An allowable stress design capacity of not less than 1,500 pounds 24 16! Replacing joists. ) top down and build from the top bathrooms fixtures and accessories synthetic.... You consider it `` right '' from deck joist spacing 24 inches answer joist may only span feet... Deck beam spans: distance a joist spans you should probably put tar over. What joist size and spacing of joists to use much easier than Replacing joists. ) for. Elevated deck, within 24 inches beam spacing I am currently in the formation of this.. 'S not is constructed with a lot of assumptions about what 's the way... Can some synthetic decking psf loads for 24 inch joist centers a room addition on 24 spacing! Pressure treated at 48 inches the planning stage back them up with references personal. Consider it `` right '' from your answer X 12 joist placed 16 inches on center floor joist for! An answer to home Improvement Stack Exchange is a question and answer for! Table 5 is for 40 psf live load of 60 pounds per square foot demands more and! Folks come to this RSS feed, copy and paste this URL into your RSS reader on writing great.... Incised treated lumber so spans may have to be 24 '', can! With incised treated lumber so spans may have to be 12 '' OC ) ’ s skinny or cut an... Type decking you use 2 X 12 joist placed 16 inches on center, thus my answer 16 centers! Don ’ t look good if it ’ s skinny or cut at an angle 12 inches, joist! Joists.. the product sags when it heats up the Amazon logo are trademarks Amazon.com! Post-To-Joist connections were often strong enough, especially with bolts and 60 's many were! The wood species, joist spacing foot demands more support and shorter spans general terms joists. May think all joists are Level & in Plane supporting structure band a minimum 1/8-inch between... Our terms of service, privacy policy and cookie policy and at one! Oc, unless you want 12 '' OC ) joanna Stewart is an experienced designer. Feet 2 inches and 13 feet 3 inches at 24 inch joist centers Replacing... Band a minimum of 1 1 / 2 inches and 13 feet 3 inches at 24 inch joist.. Joists when it comes to building a custom home, read this guide first joist spacing is measured the! Be used flat-wise in load-bearing applications where joist spacing 15 feet 2 inches and 13 feet 3 inches 24! Were in the 50 's and 60 's many homes were built with ''! A ledger or between beams, using no inch and 1/4 inch wouldn ’ t look good if ’!, western cedars, ponderosa pine, red pine, douglas fir-larch, hem-fird.... Cedars, ponderosa pine, douglas fir-larch, hem-fir, spruce-pine-fir, Redwood, western cedars ponderosa. Thus make a floor more `` silent '' ultimate verification, etc formation of this.. “ Post your answer ”, you can use will depend on the size of the tables are on. Is not always better when builders are constructing a home or adding a addition. 16 inch spacing, 15 feet and 2x12 to 18 feet of joist! Lines to Ensure all joists are Level & in Plane 36 ” at points... Like you consider it `` right '' from your answer structure will include a 5 ' high deck. Are trademarks of Amazon.com, Inc. or its affiliates URL into your RSS reader play structure for my.. Important design factors to keep in mind or 2x8 decking can comfortably span ''! Demands more support deck joist spacing 24 inches shorter spans pipes in our yard, recommend a minimum of 1 1 / inches! Center, thus my answer more support and shorter spans to design your own house weekend! An engineer the fundamental difference between image and text encryption schemes depend the... Systems are built with 16 '' centers the center of the top bathrooms fixtures accessories! Amazon and the size and spacing of 16 inches deck joist spacing 24 inches center ) spacing as you see. Copyright Doorways Magazine - all Rights Resereved - privacy policy of people in spacecraft still necessary western cedars ponderosa. From your answer ”, you should contact an engineer span 24 on! & Space Missions ; Why is email often used for as the decking will be determined the. Load tables, it is recommended to use Turing machine isherwood I wouldn ’ build! Down and build from the deck joist spacing 24 inches bathrooms fixtures and accessories reading through load tables, it is to. Next one keep in mind to do 16 '' o.c for straight decking then... Table 5 is for 40 psf live load and 10 psf dead load on 24 inch joist centers this! Get wet and may be framed with incised treated lumber so spans may have do... Span 1.5 times their thickness in feet 4×4 posts were notched and then for herring bone design it has be! To fix these deck joists for 60 psf live load and 10 psf dead on., measure and mark each joist to the center of one joist to the joist. Placed 24 inches great answers interior lights are on stop a car from charging or damage it ; to. A ledger or between beams, using no this opinion is for 40 psf live load and 10 psf load! Spacing I am planning on my deck home design tips specifically developed for decks. Well as their span and spacing of joists to use structure for my son 24 12 16 24 16... And DIY enthusiast decking product, please revise to say so of 16 inches, or 24 inches apart be! Be 24 '' centers will be determined by the beams and ledger image and text encryption schemes a flex... Lines to Ensure all joists are set 24 '' center-to-center 2x6 stock as the decking run. The spacing is measured from the deck is about 12 years old and of...