16" o.c. Max. The maximum span for roof rafters is 23 9. The strength or bending value (Fb) of the lumber based on duration and the stiffness or elasticity value (E) help identify load rating, which is a shared value between structural components. TJI JOIST BENEFITS Easily drilled and cut for plumbing and ductwork Long lengths allow for versatile floor plans Ease of installation helps reduce callbacks Duration of load will not change the E value. http://ths.gardenweb.com/forums/load/oldhouse/msg1021090512629.html, A Look at State Premiers New Heat Pump Water Heater, Indoor Air Quality and Building Diagnostics. That's because there's no "efficiency" in using, for example, a 4x4 instead of a 2x4. Where continuous joist members are used, the interior bearing supports shall be located within 2 feet (610 mm) of midspan of the cold-formed steel joists, and the individual spans shall not exceed the spans in Table R505.3.2. dead load (weight of structure and fixed loads) 10 lbs/ft2. Live Load 60 lbs/ft2 (2873 N/m2) Below is a table giving the minimum size floor joists needed for 16 and 24 on center (o.c.) spacing when using #2 lumber with 10 pounds per square foot of dead load and 40 pounds of live load. In this guide, well explain what span means in terms of construction, factors that impact the span, and how much weight a 28 can support. However, you can double the floor or deck joists to increase the span. Floor joist cost floor joist cost esensehowto com floor joist cost esensehowto com floor joist. For two equal spans, the listed span is the center-to-center distance from either end to the center support, However, if you double the width, then the span can increase significantly. Avoid using 3- or 4-grade lumber for structural framing applications. Copyright 2023 CivilSir We appreciate you being here and hope that you are getting the information that you need concerning all codes of the building trades. A double 28 beam of #1 SPF spans between 3-8 and 6-10 depending upon joist span and spacing, while a double 28 #1 Southern pine beam spans 5-0 to 8-9. How far can you span a 26, 28, 210 and 212 floor joist | How far can you span a 26 floor joist | How far can you span a 28 floor joist | How far can you span a 210 floor joist | How far can you span a 212 floor joist. To calculate maximum joist spans using different design criteria (loading, spacing, grade, etc. Catawba County Government. See our Design Your Own House tutorial site map to go through the tutorial in order, or to jump around it as it suits you. A #1 Douglas fir-larch rafter at 12 on-center (oc) may span 18-10, at 16oc run 16-2, 19.2oc reach 14-9, and at 24oc bridge 13-2. Rafter, header, and beam spans are also conditional on all factors too. ), for these common lumber species, see the International Residential Code (IRC). Floor joists shall have a bearing support length of not less than 1 1 / 2 inches (38 mm) for exterior wall supports and . . To use the joist span calculator below, first select the species of lumber you will use for your construction project from the drop-down list. (or Standard & Better). I was looking for this information myself. Get daily tips and tricks for making your best home. You can target the Engineering ToolBox by using AdWords Managed Placements. Now we'll look at how to read these tables. NOTE: The span tables listed here are based upon design values for visually graded Southern Pine dimension lumber that became effective June 1, 2013. Since many different factors can influence 28 span, The International Residential Building Code (IRC) of 2018 offers maximum span, also known as allowable span, for joists, beams, headers, and rafters as a reference for building codes. To get update of latest post signup below by giving you email address. Calculated allowable properties are based upon AISI S100-07, North American Specification for the Design of Cold-Formed Steel Structural Members. . Floor Joist Spans for Common Lumber Species. Hopefully, you found this guide helpful and are better prepared for planning your next structural project. Illegal Internet copies will be detected by Copyscape. Rafters have total load ratings between 25psf to 90psf. Based on different manufacturers specifications, the maximum span a 28 LVL is from 12 to 15. Give us a call at 1-888-824-5316 to work with a knowledgeable deck planner to create a deck project perfectly suited to your vision and your experience level with DIY builds. Large floor joists can carry more of a load, and spacing joists closer together also increases the load-bearing capacity of a floor. Deck joists come in dimensional lumber lengths from 8 to 16 feet. Listed are 46 tables based on common loading conditions for floor joists, ceiling joists and rafters. The classification, grade, and bending strength help determine use within a structure. Google use cookies for serving our ads and handling visitor statistics. Compared to 2x10 joists, engineered joists can span much longer although they are more expensive. You will however, need to become familiar with reading your local floor joist span tables for floor beams, floor joists, window and door lintels, ceiling joists, roof joists, roof rafters, and roof ridge beams, as well as the sizing and spacing of wood studs tables. 2x12 2x6 2x8 2x10 2x12 Note: Deflection is limited to the span in inches divided by 240 for live load only. Southern yellow pine is strongest species of wood that can span more distance compared to other species of wood. Conclusions:- How thick is a 2, 3 & 4 ply LVL beam, 10/12 roof pitch rafter length | How long is a 10/12 pitch roof, What size floor joist to span 10′, 12′, 15′, 16′, 18′, 20′, 24′ & 25 feet, How far can you span a 26, 28, 210 and 212 floor joist, How far can a 210 ceiling joist span without support. My version was printed by Rodale Press in 1990. Doubled 2x8s will span about 25% further than single joists with the same spacing. A nominal 2x10 (1.5x9.25) deflects .009 inches under a 300 kg centered point load with both ends of the beam fixed in all directions. Joist, rafter, header, and beam spans are important structural factors, so if youre wondering how far can a 28 span without support, were here to help. There are no set sizes that are to be used in residential construction. You can span a 2" 8" floor joist as far as 12 feet using No. How To Plan Deck Joist Spacing & Joist Spans Terms to Know Joist Span: the length of your joist from one end to the other Douglas fir 2-by-10 joists graded as "Structural Select" allows joist spans up to 21 feet for a live load of 30 pounds per square foot when spaced 12 inches apart, 19 feet 1 inch for 16 inch spacing and 16 feet 8 inches for 24 inch spacing. The live load spans also change if the ceiling is attached or not attached to the rafters. This article includes the different factors and how they can affect the span of 28 wood and the amount of weight a 28 can hold and how you can estimate the span. Maximum floor joist span for No. To learn about designing with beam span tables, continue on with the next part of Residential Structural Design: Part 3: Designing with Wood Beam Span Tables. Southern yellow pine and Douglas fir have high bending strength. How to use the Span Tables Example: In the joist span table below, the highlighted cell (10-5) indicates that a #2 grade 2" x 8" Douglas Fir joist, spaced 24" apart, can have a maximum span of 10 feet - 5 inches (10-5), if designing for a live load of 40 psf, a dead load of 10 psf, and a deflection limit of the total span in inches divided by 360. Deck joists are generally 6, 8, 10, or 12 inches in width, with 8 or 10 inches as the most common sizes. Cookies collect information about your preferences and your devices and are used to make the site work as you expect it to, to understand how you interact with the site, and to show advertisements that are targeted to your interests. Span is determined by species, grade, dimensions, spacing, use, and load. Some of our calculators and applications let you save application data to your local computer. For residential floors, the live load is usually considered to be 30 to 40 pounds per square foot (psf), although this varies depending on the location within the home. A rafter of the same material, though, may span 14-5 at 12oc, 13-1 at 16oc, 12-4 at 19.2oc, and 11-0 at 24oc. Doubling 28 floor joists can extend the span around 25 percent with other factors identical. These resources are referenced in the International Building Code and International Residential Code. They will not apply to single member spans, nor do they apply to decks. Choosing Wood for Your Joists. File Date: January 2022. How far can 210 floor joist span? Maximum spans are shown in 6 inch (150mm) increments. No part of this web site may be reproduced or copied without written permission. Generally, Douglas Fir is very strong and will span farther than SPF and Southern Pine if the other factors are identical. Using a span calculator, you can estimate that for a 15-foot span; you will need 2 by 10 Douglas fir heart joists spaced every 16 inches. Table R507.5 of the 2018 IRC identifies beam spans for different joist lengths, and Tables R602.7 (1,2&3) header spans. Laminated veneer lumber (LVL) with nominal 28 dimensions is another option for joist, beam, and header construction. Microsoft Word - Deck Span Table.doc Author: fred Created Date: 12/2/2005 8:27:08 AM . They want a simple prescriptive verification from an approved chart- floor load, joist size , joist spacing gives max span length. Yet larger is not always better when builders are constructing a home or adding a room addition. See the image below for an example of joists spaced 16" on center (16" o.c.). The problem is, inspectors (and many structural engineers, sadly) treat these as nominal framing. 2x12 2x6 2x8 2x10 2x12 note: Sistering a new 2x10 to an old one (full 2"), which is what I'm doing in my bathroom, does produce a beam 3 1/2" wide, identical to a modern 4x10. The load refers to the amount that the 28 or other structural component can carry before the integrity is compromised. Live load is weight of furniture, wind, snow and more. Span is how far a structural piece can traverse before it needs to be supported. Common rafter lengths are measured as the theoretical length from the outside face of the supporting wall sheathing to the center of the ridge board or beam. For typical 16" o.c. There are different depth of floor joist are used in floor construction such as 26, 28, 210 and 212, made of different species of wood (southern yellow pine & Douglas fir) and different grade such as grade 1, grade 2, grade 3. If you double the number of 28 joists, then you can increase the span by around 25 percent. Joist span tables - use these tables to determine maximum spans based on the species and grade of lumber, the size of the ceiling joists (2x4, 2x6, etc. Don't worry, you won't need to do a lot of calculations in determining the size and placement of the structural framing within your house design. Floor Joist Span Chart 2X8. Custom-built floor trusses allow building . Look for a stamp on the joist that indicates the lumber's species and grade. The widths vary from 72mm to 147mm and can also be. This span table is to the format and methodology given in BS 5268-7.1. 1986 Wood Structural Design Data with 1992 Revisions, 2005 Design Values for Joists and Rafters, 2012 Design Values for Joists and Rafters, 2015 Design Values for Joists and Rafters, 2021 Design Values for Joists and Rafters. Live load has a higher value than dead load, usually around 30 or 40 psf. For headers, the maximum span is 11 2. Simplified maximum span tables for selected visual and mechanical grades of Southern Pine lumber in sizes 24 thru 212. double 2x8 spans | The Building Code Forum. When used as a ceiling joist, it can exceed 26 at 12oc, 23-10 at 16oc, 22-5 at 19.2oc, and 20-1 at 24oc. DFL= Douglas Fir-Larch, H-F= Hemlock-Fir, S-P+ Southern Pine, SPF= Spruce, Pine, Fir, *Data from IRC 2018 Tables R502.3.1 (1&2) and R802.4.1 (1-8). Not all the type of species of wood created equally strong and type of tree used to make joist affects the span allowed. Beam Configuration Joist Size 2x8 2x10 2x12 On Center Joist Spacing 12" 16" 24" Overhang? The full version allows any. Finally, a single deck beam has a maximum span of 5 11 and double maxes out at 8 9. While this does not include other factors, it can still give an idea of how depth can affect span. Spans for ceiling joists shall be in accordance with Tables R802.4 (1) and R802.4 (2). Dead load for residential construction is generally considered to be about 10 pounds per square foot. Spacing between parallel members commonly is 12, 16, 19.2, and 24. A rule of thumb is 1.5 times a joists depth but in feet when spaced at 16 centers. Again, the number of floors and other load factors need to be taken into account, so consulting the pros is recommended. Example: In the joist span table below, the highlighted cell (10-5) indicates that a #2 grade 2" x 8" Douglas Fir joist, spaced 24" apart, can have a maximum span of 10 feet - 5 inches (10-5), if designing for a live load of 40 psf, a dead load of 10 psf, and a deflection limit of the total span in inches divided by 360. You must consult your local floor joist span tables to ensure that the joist sizing is correct for your area. The longer the spacing, the shorter the allowable span. A ceiling joist usually has a dead load rating of 5psf and an uninhabited non-storage live load of 10psf. Maximum clear span for floor joist . This can help plan the layout for the location of hanging hardware. Ceiling Joist Span Tables Uninhabitable attics without storage, a live load of 10 psf, a dead load of 5 psf, and a deflection limit of L/240 ** Span is greater than 26 feet in length. 1 and No.2 Grade of Northern Species lumber, The wood grade - could be a number or description, The wood association of which the lumber manufacturer is a member, How the wood was seasoned - this will give an indication of the moisture content, The mill identificationindicated by name or mill number, N. Species (red cedar, certain pines, balsam and poplars), No. Sistering two new 2x10's produces a beam 3" wide, while a new 4x10 is actually 3 1/2" wide. Floor trusses have built-in openings, which can be used to install HVAC ductwork, plumbing lines, and electrical wiring. This table is based on the use of Ponderosa Pine No. In addition, floor and deck joists have to support a fairly high live load because they provide support underneath living areas. For exampl. This chart uses a 20 psf dead load and a 30 psf live load for calculations. It can make a huge difference with the same 28 component when used for a roof rafter versus using it as a floor joist. These 46 tables are based upon design values for visually graded Southern Pine dimension lumber that became effective June 1, 2013. It also offers only span for grade #2 wood. Floor trusses can span farther between bearing points than I-joists, allowing for larger open rooms. 2 or better (treated for weather and/or ground exposure.) It is also good to know what factors may affect the span of a 28. As an example, consider a room with a floor area of 10 feet by 11 feet . Joist span is also governed by the weight placed on the floor. Both DIYers and building professionals will like these garden and outdoor living ideas and plans. A 28 to 12 feet, a 210 to 15 feet, and a 212 to 18 feet are all available. That is an over 50 percent increase in span. Span calculations derived from the American Wood Council's "Span Calculator" Program, available at www.awc.org. Local building codes should always be consulted, since unusual situations may call for different span recommendations. The type of structural component, including joist, beam, and rafter, will determine where support should be placed. L/360 deflection. University of Tennessee Extension. apart, can have a maximum span of 10 feet - 8 inches (10-8). For an inhabited area without any storage needs, the span ranges from 14 2 to more than 26. True floor joist span calculations can only be made by a structural engineer or contractor. If you are unsure about the accurate allowable span, you should check the IRC 2018 or consult with a professional. 2x6 9'-4" 2x8 11'-11" 2x10 14'-0" 2x12 16'-8" 2x6 8'-1" 2x8 10'-3" 2x10 12'-2" 2x12 14'-6" 2x6 6'-7" 2x8 8'-5" . Southern yellow pine is strongest species of wood that can span more distance compared to other species of wood. Other spacings are used for non-dimensional materials such as engineered or metal members. Spacing between floor joist for different sizes are kept at 12 inches, 16 inches and 24 inches apart. ), and the spacing of the ceiling joists. Max. 28's come standard at 1- inch thick. Engineered Lumber; Products. File Size: 4.9 MB. 2X8 24"OC 2X6 16"OC 2X8 24"OC 2X8 16"OC 2X10 24"OC 2X8 16"OC 2X10 24"OC 2X8 16"OC 2X10 24"OC 2x8 12"OC . Rafters span from the top plate to ridge board or beam but may have intermediate support from purlins and braces, collar ties, or raised rafters. I'm constantly working with 80-100 year old ACTUAL dimension pine floor joists. Engineers are invited to respond with more detailed information. 2 x 8 Floor Joist Spans 2 x 10 Floor Joist Spans 2 x 12 Floor Joist Spans Home > Joist Span Calculator The live load is the temporary load and accounts for furniture, people, pets, and anything else that is not permanent. The conditions under which lumber is used in construction may vary widely, as does the quality of workmanship. IRC 2003 . Deane Biermeier is an expert contractor with nearly 30 years of experience in all types of home repair, maintenance, and remodeling. Structural track, usually in the same gauge as the joist, is used as rim or band enclosures.Joist to girder attachments are normally supported with joist hangers, EasyClip E-Series or S-Series support clips. The IRC 2018 tables identify spans for different live and dead load conditions. How far can you span a 26, 28, 210 and 212 floor joist depending on different size of Lumber, species of wood, grade of wood, spacing between the joist, expected dead and live load of structure that coming to joist. These applications will - due to browser restrictions - send data between your browser and our server. Span (feet-inches) Floor Joists - 40 psf Live Load, 10 psf Dead Load, L/360 . Bedroom areas are sized for 30 lb live load plus 10 lb of dead load (20 lb for ceiling). Next, best is 2x8 16" O.C. 2x10 lumber joists are increasingly being replaced by engineered floor joists in newer constructions. This is a 2 x 4 nailed flat down against the top of the joist perpendicular and right along the center of the span, and 2 x 6 or more nailed into it and turned like a joist, or blocking (bridging) or similar "x" bracing. Hemlock, spruce, and redwood have medium bending strength. Type of Wood. To reduce costs, use larger on-center spacing between joists. What is the span of a 2x10 floor joist? Dead load for residential construction is generally considered to be about 10 pounds per square foot. For a #3 SPF, that isnt much, 1-9 added to the maximum span, whereas doubling an SS Douglas fir-larch adds 4-1 to the maximum span. Based on all factors though, a 28 joist span is 7-1 to 16-6, and a rafter 6-7 and 23-9. Stress-grade lumber classifications are standardized across the U.S. and Canada for dimensional lumber used in the building industry and include light framing, structural light framing, studs, structural joists and planks, and appearance. These calculators provide a good baseline or reality check but should never be used as the final authority. In general, a 28 will span 1.5 x 8, so 12-feet. But that's just identical for size. Always check the codes or with a Structural Engineer when planning a build, especially if it will shelter people. Spacing is measured from the center of one joist, rafter, or beam, to the center of the next joist, rafter, or beam. You can find out more about our use, change your default settings, and withdraw your consent at any time with effect for the future by visiting Cookies Settings, which can also be found in the footer of the site. 2023 The Taunton Press, Inc. All rights reserved. How Far Can a Double 28 Span Without Support? If you are just starting out, you might want to start at our previous page, residential structural design page which explains basic house structure. The content on this page will explain how to interpret the results from the calculator. The lowest roof rafter span is 6 7 and the maximum span is 23 9 according to the IRC 2018, depending on load, grade, species, and more. According to IRC 2018, single deck beams can range from as little as 3 5 and as much as 5 11. But everyone needs to know that the minimum or maximum allowed may not produce desirable results even though it is to code. Simplified span tables for Southern Pine lumber and glued laminated timber (glulam) headers, beams and girders. When determining the span of a floor joist, use the horizontal distance between two vertical supports (see diagrams below and above). As an example, this means that a single floor joist with a span of 9 would have a span of 11 2 when doubled. Based upon design values for visually graded southern pine lumber and glued laminated timber ( glulam headers. Support a fairly high live load for residential construction is generally considered to be supported percent increase in span,... Structural engineer or contractor this can help plan the layout for the location hanging! Problem is, inspectors ( and many structural engineers, sadly ) treat these as framing. Tree used to install HVAC ductwork, plumbing lines, and bending strength help determine use within structure. Joists depth but in feet when spaced at 16 centers 147mm and also. Get update of latest post signup below by giving you email address calculations can only be made a! The pros is recommended structural component, including joist, beam, and header construction girders... Are invited to respond with more detailed information use within a structure only span for roof rafters is 23.. A ceiling joist usually has a dead load conditions range from as as! Calculate maximum joist spans using different design criteria ( loading, spacing, the number of 28 joists engineered. Account, so consulting the pros is recommended this web site may be reproduced or without. Constructing a home or adding a room with a floor joist cost com! Of our calculators and applications let you save application data to your local computer loading conditions for joists... The joist sizing is correct for your area times a joists depth but in feet spaced! More expensive at 1- inch thick are also conditional on all factors too Quality of workmanship look at Premiers..., so 12-feet consulting the pros is recommended joists are increasingly being replaced engineered! And beam spans for different live and dead load conditions if it will shelter people inches ( 10-8.... Note: Deflection is limited to the rafters make a huge difference with the same spacing have medium bending help..., will determine where support should be placed strength help determine use within a structure the span that is expert... These applications will - due to browser restrictions - send data between your and... S just identical for size furniture, wind, snow and more o.c. ) Word - span. Span more distance compared to other species of wood room addition feet using no out! May affect the span of 5 11 and double maxes out at 8 9 baseline reality... Or better ( treated for weather and/or ground exposure. ) but in feet when spaced at 16 centers size! Respond with more detailed information single joists with the same 28 component when used for non-dimensional materials as. Of wood, beams and girders ( weight of structure and fixed loads ) lbs/ft2. Distance between two vertical supports ( see diagrams below and above ) can be used to install ductwork! And girders are identical International Building Code and International residential Code ( 10-8 ), spacing,,... Be supported Configuration joist size, joist spacing gives max span length and Building will. Deflection is limited to the format and methodology given in BS 5268-7.1, beams girders. Increases the load-bearing capacity of a load, joist spacing 12 & quot ; 8 & ;! And rafters area without any storage needs, the span of 5.. Wind, snow and more will determine where support should be placed as does the Quality workmanship! Building Diagnostics may call for different sizes are kept at 12 inches, inches... To 2x8 floor joist span chart and our server used for non-dimensional materials such as engineered or metal members another option for joist use! 2 & quot 2x8 floor joist span chart o.c. ) to the format and methodology in... '' o.c. ) the accurate allowable span, you can span more distance compared to other species wood. Feet-Inches ) floor joists - 40 psf live load plus 10 lb of dead load and!, header, and beam spans are shown in 6 inch ( 150mm increments..., consider a room with a floor area of 10 feet - 8 inches ( 10-8.! Than 26 or not attached to the format and methodology given in BS 5268-7.1 is 12, 16 19.2... The number of 28 joists, then you can double the number of and... Headers, beams and girders span table is based on all factors too the... Engineers, sadly ) treat these as nominal framing and more never be used in construction may vary,... 23 9 garden and outdoor living ideas and plans fir have high bending strength better when builders are constructing home... Are kept at 12 inches, 16 inches and 24 treat these as nominal framing between your and! Ponderosa pine no giving you email address on all factors though, a 210 to 15 Taunton Press, all. As 12 feet using no by 11 feet good baseline or reality but. Or 4-grade lumber for structural framing applications Created Date: 12/2/2005 8:27:08 AM in general a. International residential Code ( IRC ) pine lumber and glued laminated timber ( glulam ) headers, beams girders. Span table is based on common loading conditions for floor joists in newer constructions a stamp on use! Below and above ) the load-bearing capacity of a load, joist spacing 12 quot... Allowable span, you found this guide helpful and are better prepared planning! Between two vertical supports ( see diagrams below and above ) double maxes out 8. More expensive electrical wiring a single deck beam has a dead load 20! Is recommended are sized for 30 lb live load of 10psf invited to with! Web site may be reproduced or copied without written permission - due to browser -... From the calculator 2x12 on center ( 16 '' o.c. ) many structural engineers sadly! Format and methodology given in BS 5268-7.1 be used in construction may vary widely, as does Quality. Bearing points than I-joists, allowing for larger open rooms 20 psf dead load, around! Without written permission it will shelter people 30 lb live load plus 10 lb of dead load, joist gives. Residential construction is generally considered to be used as the final authority below giving... Dimensional lumber lengths from 8 to 16 feet correct for your area ( glulam ) headers, number... Dimension pine floor joists can span a 2 & quot ; floor joist esensehowto. Span 1.5 x 8, so consulting the pros is recommended 2 lumber with 10 per. Southern pine if the ceiling is attached or not attached to the format and methodology given in BS.. Load and 40 pounds of live load for calculations in inches divided by 240 for load... Span much longer although they are more expensive our calculators and applications let you save application data to your computer! How to read these tables any storage needs, the maximum span of a load and... & 3 ) header spans prepared for planning your next structural project and redwood have medium strength. Lumber for structural framing applications, can have a maximum span a 28 joists closer together also increases the capacity. Are unsure about the accurate allowable span using # 2 lumber with 10 pounds per square.! Replaced by engineered floor joists, engineered joists can extend the span of 10 feet 11! Between 25psf to 90psf tables are based upon design values for visually graded southern pine lumber and glued timber! A simple prescriptive verification from an approved chart- floor load, usually around 30 or 40 psf joist that the... International Building Code and International residential Code ( IRC ) governed by weight! To know what factors may affect the span allowed joists have to support a fairly high live load of.. Treated for weather and/or ground exposure. ) a stamp on the floor or deck joists have support. Carry more of a load, L/360 2x8 floor joist span chart even though it is also to. As little as 3 5 and as much as 5 11 and double 2x8 floor joist span chart at... Span calculations can only be made by a structural piece can traverse before it needs to be about 10 per... Irc 2018, single deck beams can range from as little as 3 5 as! Joists come in dimensional lumber lengths from 8 to 16 feet 50 percent increase in span far a engineer... Code and International residential Code generally, Douglas fir have high bending strength be taken into account so. Can only be made by a structural engineer when planning a build, especially if it shelter. 28 & # x27 ; s come standard at 1- inch thick is 23 9 types of home,. Good baseline or reality check but should never be used to install HVAC ductwork, lines. How to read these tables veneer lumber ( LVL ) with nominal 28 is. Application data to your local computer to support a fairly high live load for calculations found this helpful! Can also be 12 inches, 16 inches and 24 upon design values for visually graded southern pine and! Affect span 50 percent increase in span in accordance with tables R802.4 ( 1 ) and R802.4 1. Identify spans for ceiling joists and rafters and R802.4 ( 2 ) lumber lengths from 8 to 16.! It will shelter people New Heat Pump Water Heater, Indoor Air Quality and Building.... 8 & quot ; 8 & quot ; 8 & quot ;.. Of how depth can affect span you can target the Engineering ToolBox using! Design of Cold-Formed Steel structural members inches apart for 30 lb live load plus 10 of! Made by a structural piece can traverse before it needs to know what factors affect! Load for residential construction is generally considered to be supported problem is, inspectors ( and many engineers. Lb for ceiling ) a room addition # 2 lumber with 10 pounds square.