Shed roof rafter span chart. Roof slope must be 3:12 or less to use this column.

Shed roof rafter span chart Maximum Rafter Span Chart Rafter Span Tables Use these two tables for roof rafters with a slope of 3" in 12" or less. This comprehensive guide covers maximum allowable spans, the impact of species and grade, common building code requirements, and practical design Only with ceiling joists located near the base of the rafter at the bearing wall (1/7. Span Calculator for Wood Joists and Rafters Enhance the precision of your projects with our advanced Span Calculator, updated to reflect the 2024 NDS Supplement - Design Values for Wood Construction. Discover a comprehensive 2x4 roof truss span chart and roof truss calculator to determine the perfect roof span and specifications for your project. There is no standard spacing – it depends on what size of rafters you want to use, and the span of your shed. for Douglas Fir-Larch #2 or Southern Pine #2 for 10 Lb. To calculate maximum spans of additional species of lumber, use the Span Calculator or the Span Tables for Joists and Rafters on the American Wood Council website. 5 or less) May 5, 2009 · The roof is going to cover a portion of my deck, which I’m planning to screen in. Douglas fir maximum horizontal roof rafter span for Lumber Grade Selected Structural and No. Optional Pitch Inches of rise per 12 inches of run. Note: The required bending design value, Fb, in pounds per square inch is shown at the bottom of each table and is applicable to all lumber sizes shown. Use these simple calculators to size Trus Joist TimberStrand LSL, Parallam PSL and Microllam LVL beams and headers and Treated Parallam Plus PSL deck beams and columns. These crucial structural members support the sheathing, shingles, and everything else that protects you from the elements. I was wondering if there was a way to calculate the rafter length? I am going across the 12' span and one wall is 10' high and the other is 12' high. The tool accepts mixed number and decimal inputs for accurate calculations in both feet and inches. dead load (weight of structure and fixed loads) 15 lbs/ft2. The maximum spans provided in these tables were determined according to criteria set forth by the American Forest & Paper Association in its code-recognized Span Tables for Joists and Rafters. 16 or 24. Interactive roof and rafter calculator for gable, shed, saltbox, hip, valley, blind valley, gambrel, polygon, and bay window roofs. May 22, 2025 · Improper spacing can lead to roof sagging, leaks, or even collapse. This tutorial module explains how to design with roof rafter span tables. How to Size Roof Rafters Sizing Roof Rafters – Example 1 Question: Where the ceiling is attached to the rafters, what is the maximum allowable span of a 2×6 Douglas fir-larch #2 roof rafter spaced 12 inches on center supporting a roof live load of 20 psf and a dead load of 10 psf? First step, lets collect all Free rafter length calculator for 2025. How far can a 2×6 , 2×8 , 2×10 , 2×12 & 2×14 rafter span Rafter size for 10, 12, 15, 16, 18 , 20 & 24 foot span A rafter is a structural component that is used as part of a roof construction. Plus, learn the rafter length formula. Sep 21, 2025 · A shed roof relies on simple rafters that run from the ridge or peak to the exterior walls. See Chapter 23 for complete requirements. What Is a Roof Joist? A roof joist is a horizontal structural member used in framing to span an open space and support a ceiling or floor. This is Module 7, Part 4: Roof Rafter, Joist and Beam Design of the Design Your Own House Tutorial. In roofing, joists carry the roof load and transfer it to walls or beams. Vizualizacija 3 D, as well as drawings and design data for all the rafters are generated in real-time. Calculators are for use in U. org for lumber span calculator. g. Check ground snow load for your area. May 22, 2025 · What Determines 2×8 Roof Rafter Span Limits? The maximum span of a 2×8 roof rafter depends on several structural and environmental factors. Dec 13, 2024 · Maximum Rafter Spans for a Patio Roof Next, calculate beam placements and how best to coordinate them with the rafters. Whether you're building on walls or setting rafters on beams, calculate precise rafter lengths, angles, and generate detailed cut lists. Rafter is the beam supporting the building. Whether building a small garden shed or a larger storage structure, understanding the appropriate rafter lengths and spacing is essential. Roof Rafter Spacing, Span, and Sizing Requirements Roof Rafter Configuration. I don't want to use webbed trusses because I will lose the vaulted ceiling. Hr = Height of roof ridge measured vertically above the top of the rafter support walls. View your project in 3D to ensure SFPA offers 46 span tables or three types of Southern Pine lumber framing members: floor joists, ceiling joists, and rafters. 2, are indicated below. Perfect for builders and DIYers alike. It helps determine the number of rafters based on the building’s length important for roof Oct 17, 2023 · For a particular span, rafter spacing distance can vary based on the species of lumber, grade, and load conditions. This article explores the essential Sep 15, 2025 · This article provides a comprehensive shed roof rafter span table and detailed guidance to ensure proper sizing based on roof pitch, load requirements, and building materials. The Rafter Span Calculator is a powerful, user-friendly tool designed to help builders, contractors, and DIY enthusiasts calculate the maximum allowable span for rafters based on lumber type, spacing, roof pitch, and load. Understanding how to use a rafter span chart is essential for ensuring a safe and code-compliant structure. The Rafters for Gable Roof calculator computes the total number of rafter boards (roof joists) for a gabled roof based on the ridge length, pitch and span. For sloping rafters, the span is measured along the horizon-tal projection. Oct 28, 2025 · The following guide explains how to use a Shed Roof Rafter Span Table to size rafters for common single‑slope and gable shed roofs, including span limits, lumber grades, load assumptions, and practical tips for safe construction. Calculate exact rafter lengths for roof framing including common rafters, hip rafters, and lean-to rafters with birdsmouth cuts. It'll help you decide on its size, roof type, and overhang length, and find the span of the roof rafter required. I would like to do a mono-pitch (aka single slope) roof with a span of 16 feet with a vaulted ceiling. Rise Vertical distance from top of wall to ridge. Input the rafter span (on the flat), eave overhang and pitch of the roof. S. For heavier roof covering contact the Building Division office. By following the steps within this guide, you will be able to build and frame a lean to shed roof like a pro. Rafter loading is for light roof covering (3-tab, metal, shakes, shingles) plus live load. Enter the slope, width, overhang, heel height, kneewall and lumber sizes to get a dimensioned side view of the common rafter. ICC Digital Codes is the largest provider of model codes, custom codes and standards used worldwide to construct safe, sustainable, affordable and resilient structures. applications only. To calculate maximum joist spans using different design criteria (loading, spacing, grade, etc. Span Total building width from wall to wall. Jun 11, 2025 · Roof Pitch: 6/12 Roofing Material: Asphalt shingles Rafter Selection: The homeowner chose to use 2×8 Southern Yellow Pine rafters due to its high strength and availability. A very good Span Calculator from the American Wood Council. Additionally, compression perpendicular to grain design values (F c⊥) are included as a consideration for selection of joists and rafters. 2” spacing, and the spacing when using metal roofing and for lean-to and porch roofs. Finally, fasten the rafters to the to shed walls with rafter ties and install the plywood roof decking on top of the lean to shed roof. Overhang Length rafter extends past the wall. Use our rafter length calculator to see how long your rafters need to be when framing a roof or truss. Includes visual diagrams. Calculate precise rafter lengths using roof pitch and span measurements to ensure accurate and efficient roof framing and construction. This guide explains how far a 2×8 rafter can span under different loads, roof slopes, and wood species, and provides practical tips for sizing and installation to meet U. Whether you’re working on a gable, hip, or shed roof, a rafter calculator helps you select the right size based on your roof’s slope, materials, and overall design specifications, fostering your creativity while ensuring safety. live load. Yes, the Rafter Span Calculator can be used for various roof designs, including gable roofs, hip roofs, and shed roofs, by adjusting the input parameters accordingly. Use the diagrams on this page when referring to the Input section and to interpret the calculated Results. With this tool, you can accurately calculate rafter dimensions, roof pitch, and cross-sectional properties - all crucial for ensuring the strength and durability of your structure. May 18, 2016 · The load on an outside wall with clear span trusses is exactly half the load on each wall. The maximum rafter span is the horizontal distance a rafter covers between supports, dictated by lumber size, spacing, species, and local building codes. This article explores the recommended shed roof rafter spacing based on shed size, roof type, materials, and local building codes, helping builders and homeowners achieve a strong, long-lasting roof. 2×6 roof rafters are commonly used in many residential and light commercial projects, but their allowable span depends on several key factors. Rafter Spacing Distance between rafters, e. Free online roof truss calculator tool. Open this link in another window and then follow the directions below to learn how to use it. Dec 27, 2024 · Building a sturdy roof, whether for a new home, an addition, or even a backyard shed, hinges on correctly sizing your rafters. A reliable shed roof rafter span table helps builders select the right lumber and spacing, reducing the risk of sagging or structural StruCalc’s roof beam calculator supports ridge beam sizing, rafter load analysis, and flitch beam checks for safe, code-compliant structural design. Span, for joists and rafters, is the clear distance between sup-ports. I want to use 36 inch centers for the rafters and the span is 16 feet with a 2/12 pitch. Is there a formula that can give me a. Mar 28, 2022 · Check awc. Roof Framing - Learning the basics of roof building, and how to build a roof using the roof pitch calculator. Calculate roof rafter lengths for various roof types with precision. Just enter the measurements of the overhead, length of roof span, and pitch or angle, and you’ll have the rafters of the perfect size for your roofing project. The span is defined as the horizontal distance the rafter must cover without intermediate support. It provides detailed drawings of the rafter system, battens, and materials suitable for both rigid and flexible roofing. Truss Calculator Use this simple top cord truss calculator to estimate your rake (rafter) length for your next project’s roof sheathing requirements. Span table based on WWPA Western Lumber Span Tables, Edition 2/94. Use this rafter length calculator to make sure you got your roof truss dimensions right. The rafter span indicates the maximum distance a rafter can safely cover while supporting the roof load, given lumber size, species, roof pitch, and local conditions. I mention floor but there are calculators and charts for rafters too. Design and construction of roof is depending on many factors but one of the most common important factor is climatic and weather condition of Explore a searchable database of US construction and building code. These include the wood species and grade, roof pitch, load duration, type of roof covering, and local building codes. We’ll discuss 16” and 24” spacing, how to calculate the number of rafters required, 19. This article provides a detailed shed roof rafter span table, exploring factors affecting rafter size and span, and offering practical advice for shed What Is a Rafter Calculator? A rafter calculator is a construction tool used to determine the length and angles of rafters for pitched roofs. When constructing a lean-to roof — whether for a garden shed, home extension, carport, or patio cover — one of the most important design elements to get right is the roof pitch. This dynamic tool provides everything needed to design single-slope roofs, commonly used in sheds, lean-tos, and other structures. Beams You'll also find theories on hip rafter shift-offset, standard roof framing kernel trait drawings, German Schiften DP-Shadow Line techniques, folding net roof surface and net plane geometric development, when hip rafters collide, the Warlock Cut, and developing upper and lower claws on rafters using Axioms. To calculate the maximum spans of species not shown above, use the Span Calculator or the Span Tables for Joists and Rafters on the American Wood Council website. Has anyone ever come across a spanning table that doesn’t require Eienstein to decipher? The calculator provides online calculation of the rafters for shed roof according to your original dimensions. This rafter length calculator determines the total length of a roof rafter based on the building width, overhang, ridgeboard thickness, and roof pitch. Straight-line interpolation shall be permitted for intermediate spans and design values. Free online Roof Framing Calculator to easily calculate rafter length, pitch, and spacing for sheds, homes, and lean-to roofs. Perfect for sheds, garages, and house roofs. Simply select your member type, size, species, spacing, and span length to instantly check compliance. RAFTER and JOIST SPAN TABLE City of Arcata, California Building Division Informational Handout The following When ceiling joists or rafter ties are located higher in the attic space, the rafter spans shall be multiplied by the factors given below: Where: Hc = Height of ceiling joists or rafter ties measured vertically above the top of the rafter support walls. Jul 10, 2025 · Basics Of Shed Roof Rafter Spans Proper rafter sizing is vital for any shed roof to prevent sagging, bowing, or even structural failure. Calculate rafter length, roof pitch, truss dimensions and costs. Rafter spacing is the horizontal distance between the parallel rafters measured from one rafter’s center to the next one. Horizontal Roof Rafters - Maximum Spans Douglas Fir in horizontal roof rafters and maximum spans. Calculate all rafter dimensions and cut angles to frame a roof - Inch Rafters Drywall or no finished ceiling, construction load20 PSF live load Roof Pitch Calculator Roof Style Select the type of roof: Gable, Hip, or Shed. Flat -- The most economical flat truss for a roof is provided when the depth of the truss in inches is approximately equal to 7% of the Sep 8, 2025 · 2×8 roof rafter span is a key factor in roof framing that affects structural safety, material cost, and attic space. What Is a Rafters Calculator? A Rafters Calculator is an online or digital tool designed to quickly compute the length, pitch, and angles of roof rafters based on user input like: Roof span Rise Run Roof pitch (angle or slope) Overhang (optional) It uses trigonometric formulas to compute the rafter length, slope angle, and birdsmouth cut position accurately. Find rafter length instantly with our free Roof Rafter Calculator. Jul 13, 2025 · Choosing the right rafter span for a shed roof is vital for structural integrity, safety, and durability. 1 and No. This on-line span calculator will size floor and deck joists and roof rafters for most conditions. Find the maximum spans of rafters for different species, grades, loads, and spacing. See tables for roofs with or without ceiling attached to rafters, and use the span calculator or the American Wood Council website for more options. Roof Rafters and Shed Roof Pitch When talking about framing a shed roof with rafters, you’ll first need to know how steep your roof is – in other words, what is the pitch or slope of your roof? Most rafter span charts are organized into 2 sections: roofs with a slope less than 3:12 and roofs greater than 3:12. Max. Rafters Rafters are sized the same way as joists: Establish live load, dead load and deflection limits; use the appropriate rafter table to determine acceptable Fb and E values; and then select the appropriate species, size and grade from AWC’s Design Values for Joists and Rafters publication. One side will fasten to the house and the other will sit on a support beam. The calculated spans assume fully supported members, properly sheathed and nailed on the top edge of the joist or rafter. They work with rafters and trusses to ensure the roof remains structurally sound and secure. For standard shed roof rafter spacing, see rafter span chart. Nov 29, 2023 · Next, plan out your lean to shed roof rafter spacing and position the rafters in place. Code regulations are consolidated by state and city for easier navigation. Likewise, a 2×10 rafter can typically span from 14 to 23 feet, while a 2×12 rafter can typically from 17 to 28 feet. Check sources of supply for availability of lumber in lengths greater than 20′. Live load is weight of furniture, wind, snow and more. The Rafter Length Calculator is engineered for fast and precise computations of key roof rafter parameters. Shed roof rafters must accommodate load requirements and roof design, which vary based on factors such as roof pitch, lumber size, wood species, snow load, and spacing. Main features of the calculator: Calculation of roof geometry, including the span width and overhang length A useful shed roof rafter calculator to calculate the rafter length for the given dimensions of the roof of the building or a structure. A rafter is a structural component build of wood or steel that is used as part of a roof Mar 21, 2025 · A rafter is an important structural component for roof construction, and if you’re planning for a project, you might be wondering about the proper rafter spacing and sizing. Use this column when the roof slope is steeper than 3:12. Sizing rafters differs from sizing joists in 2 ways: Optimize your shed and structure projects with our Online 3D Single-Slope Rafter Calculator. Easily calculate roof rafter length, pitch, rise, and span using our Roof Rafter Calculator. Although my home will be on a crawl space foundation (wooden floor The roof truss calculator is a handy tool that will help you estimate both the rafter length and the number of trusses needed for your roof. May 22, 2025 · Shed Roof Rafter Span Table and Guide for Optimal Construction When building a shed, selecting the correct rafter span is crucial to ensure structural integrity, safety, and durability. Accurate for any span, pitch, or overhang. Typically, it runs from the ridge or hip of the roof. pro is online shed roof calculator (single slope, pent roof, skillion) - program determines basic material consumption for roof building, roofing underlayment volume, all quantitative and dimensional values of the shed pent roof truss system: Dimensions and area of a shed roof, materials quantity for it, the roof angle (pitch); Number of rafters and their dimensions; Roof battens (lath A rafter is a structural member that provides support for the roof sheathing and transfers the weight of the roof to the exterior walls of a building. Rafter spacing is the distance between the centers of two consecutive parallel rafters. I would like to have a 1' overhang on both ends. Perfect for roofing, framing, and truss planning. To calculate the roof pitch angle from rise and run, use the Roof Pitch to Angle Calculator. It includes the rise and works in feet and inches or metric values. Sep 9, 2025 · Determining the correct 2×6 roof rafter span is essential for safe, efficient roof framing. Simply, floors need more capacity than roof, so for 10', 2x8 will be more than enough. I'm about the embark on my own DIY home build. Whether you’re a DIY hobbyist or a seasoned builder, this calculator simplifies the process of determining roof pitch, rafter length, and material requirements. Rafter Spacing Calculation: Using a span chart and considering the wind and snow loads, the homeowner determined that a rafter spacing of 16 inches OC was required Apr 21, 2015 · Calculate the length of lean to shed roof rafters for any common roof pitch when the top of the rafters stop into a wall. For 20 Lb. These span tables assume installation of at least three joists or rafters that are spaced not more than 24" on center. For example, if building is 24′ x 24′ and has trusses, and the load on the roof will be for 30 lb snow load and a ceiling with no storage will total out like this. What factors affect the rafter span? Factors affecting the rafter span include the type of wood, the spacing between rafters, the slope of the roof, and the load per square foot (including environmental factors like snow and wind). These span tables for joists and rafters are calculated on the basis of a series of modulus of elasticity (E) and bending design values (F b). Calculating the length of the rafters is an essential part of framing a roof. By using the span table effectively, builders can avoid structural issues, maximize safety, and optimize material costs. This guide explains span limits, factors that affect allowable spans, and provides practical charts and examples to help builders, remodelers, and homeowners make informed decisions. A “span options” calculator allows selection of multiple species and grades for comparison purposes. Kalk. ) for these common lumber species, see the International Residential Code (IRC). SHINGLE ROOFMETAL ROOF Free online rafter length calculator tool. By using this tool, you can save time, avoid costly mistakes, and ensure your roof structure meets building code requirements. ALLOWABLE SPANS IN FEET & INCHES #2 Spruce-Pine-Fir #2 Spruce-Pine-Fir Nov 6, 2024 · Learn the basics of shed roof rafter spacing and construction, including span tables, framing, and load calculations for a sturdy and safe shed roof. The Lean-To Roof Pitch Calculator simplifies this task by helping you calculate the angle, rise, run, and slope based on your specific dimensions or preferred pitch ratio. This chapter provides guidelines for roof and ceiling construction based on the 2018 International Residential Code for safe, sustainable, and resilient structures. building codes. Understanding these guidelines ensures a well-supported roof that withstands weather and load requirements. Explore a searchable database of US construction and building code. Now, in order to correctly size roof rafters, lets take a look at a few examples. dead load, 30 Lb. I cannot find appropriate span tables for mono-pitch roof trusses constructed of a single 2x10 or 2x12. In this guide, we’ll explain rafter spacing, code requirements, roof rafter span tables, and rafter spacing calculators. This calculator is to be used as an estimating tool only. Joists and rafter spans for common loading conditions can be determined. For Canada switch to Canada Sizing Table Lookup. It simplifies the math involved in roof building by computing: Rafter length Pitch/slope Rise and run Cut angles Whether you’re building a shed, porch, gable roof, or full residential roof, this calculator saves time and ensures accuracy. In general, a 2×6 rafter can typically span from 9 to 14 feet, while a 2×8 rafter can typically span from 12 to 18 feet. May 19, 2025 · Choosing the right size and span for roof rafters is crucial to building safe and durable structures. Click the button to calculate the stock size needed for this job. Select the application below you are looking to calculate. This tool is designed to provide accurate maximum span calculations for a wide range of commercially available softwood and hardwood lumber, including prominent species such as Douglas Fir Nov 17, 2023 · Hello, I am building a freestanding 12'x16' lean to shed. Oct 17, 2025 · This article provides a comprehensive shed roof rafter span table and explains how to select the appropriate rafters for different shed sizes and roofing materials. Calculate the dimensions and angles of a shed roof with Easy Rafters. Can I use different rafter spacings for my roof? Calculate all rafter dimensions, cut angles and placements to frame a Lean To Roof - Inch Use our free Rafter & Truss Calculator to calculate rafter lengths from rise and run measurements. Oct 3, 2024 · Incorrect span calculations can lead to structural failures. Read the Tutorial for Understanding Loads and Using Span Tables. Aug 17, 2021 · A 2x4 roof rafter span is limited to 10'10" with 12" on-center spacing. The program will calculate the parameters and the length of the rafters of a shed roof (length of the rafters, length overhang, the angle of the saw cut, the distance to drinking). This comprehensive guide will equip The Shed Roof Calculator is a must-have tool for anyone planning to construct a shed. snow load, the 2x4 roof rafter span drops to 8'5" and 9'0" for Douglas Fir-Larch and Southern Pine respectively. What does 3:12 mean? It means a roof that rises 3 inches for every 12 inches of The roof pitch calculator calculates rise, run, slope, pitch, angle, and rafter length. Nov 13, 2003 · The following table represents the minimum standards for roof rafters, ceiling joists, and floor joists contained within the 2001 California Building Code and can only be used for projects conforming to conventional light-frame construction. Use our DIY shed cost calculator to estimate the cost of building a DIY shed. dead load, 20 Lb. In addition, a 2×14″ rafter can typically span up to 23 feet. Aug 21, 2023 · Easily calculate the length of your shed roof rafter with our online Rafter Length Calculator. Results will Quickly determine if your joist or rafter spans meet the 2021 IRC requirements using our easy-to-use Span & Spacing Calculator. This tool is also useful for designing lean-to roofs and other single-pitch structures. Spans are shown in feet-inches and are limited to 26′ and less. Fast & accurate results. SFPA offers nearly 100 span tables for treated Southern Pine lumber, joists and rafters, and headers and beams. Roof slope must be 3:12 or less to use this column. The online Single-Slope Roof Calculator helps determine rafter dimensions, roof pitch, and required roofing materials. lab jhx ffr jzqop nltxcif xaeq cakhh mndh gglehl rtl ujrs cymjaw mflxu vdwlb ggsdonm