# Rafter Size Calculator

As long as you use the top cut illustration in “Connection # 1," then this rafter will be cut the same length as the king common rafter adjacent to it. Example of figuring rafter length. Rafter Length From Roof Slope in Degrees using Metric Measurement. But we aren't building a cat house! How Do You Calculate Rafter Length? Let's go back to geometry. Use the calculator below to determine rafter length. Algebra 2B: Trigonometry Unit Test practice Part 1 Without Calculator, Part 2 with Calculator Short Answer Determine whether the function shown below is or is not periodic. The most critical step in cutting roof rafters is calculating the measurements for your cuts. How to calculate the angles and sides of a triangle? A triangle is determined by 3 of the 6 free values, with at least one side. For a good straight fascia, add an extra inch or 2 to the tails of all your rafters (total length). Assemble the rafters as shown above. Search and filter Rafter J Ranch homes by price, beds, baths and property type. A beam used to support another beam, rafter or truss and eliminate a column support. A "binding rafter" is not a rafter but an obsolete name for a purlin or support. The Ontario Building Code | Spans for Joists, Rafters and Beams 9. Rare River frontage located on the beautiful Tellico River. Measure the length of the valley rafters (Photo 9) and cut them using Figure C as an angle guide. If it is, find the period. joist and rafter spans for specific grades of So ut hernP il mb. All the figures are based on roofing tiles or slates laid on timber laths over sarking felt. For a good straight fascia, add an extra inch or 2 to the tails of all your rafters (total length). The Length of roof sheets are manufactured to your requirements. Larger section rafters will do nothing to prevent rafter tail and wall top spread. The column on the left of each chart labeled BEAM SPAN represents the beam length (with bearing) required for your project. If you've just joined us, we were discussing how beam size is crucial especially when you have to support a hot tub with 8,000 lbs of hot water and bathers. From your average hip roof calculator to something more specific like a hip roof rafter calculator, there is plenty to consider with this kind of calculation! To do this, your best bet is definitely finding a good hip roof construction calculator so that you can work it all out in a timely and simple fashion. Where possible, I size and locate dormers between existing rafters. For our rafter 5. For example, a 46-1/2-inch-wide gable dormer (exterior measurements) leaves only two rafters to be cut and headed-off, and that won't require doubling the common rafters on either side. In this example we will calculate the weight and Board Foot Measure quantities of decking for a proposed patio roof. Enter this measurement into the calculator and select a roof pitch and the length of the rafter will automatically returned along with the rise. How to Calculate length of Roof Rafters Using Angle | Roof Truss L & T - Learning Technology May 18, 2019 If you like this Video, then share it with your friends on social media. Jack Rafter Spacing This menu option allows you to set the jack rafter On Center spacing of the jack rafters. That truss count number less 1 times 6 ( count-1×6=total ) is the number of OSB web pieces you'll need to cut. Roof Framing Simplified This direct approach involves full-size layouts and stringing rafter lines There isn't a cut in roof framing that can't be calculated given a sharp pencil, a framing square and a head for math. Then click on Calculate, to compute the other values. In this example we used the ConstructionCalc Wood Beam Calculator to make the calculations for us so our deck doesn't collapse. This gives the total center height of the rafters. 272 Rafter Rd, Tellico Plains, TN 37385 is a NaN sqft Lot/Land listed for $89,000. Dimension lumber can be purchased as dry or. Then I found that the 4067 model does calculate total rafter length including the rafter tail. Rafter Length From Roof Slope in Degrees using Metric Measurement. It can seem intimidating at first, but with a roofing calculator, you can make quick work of the mathematical portion of the job. Size of support timber for shed roof I am building a shed with a 12' x 6' floor space I am planning a single span and single pitch roof constructed from timbers about 18" apart and covered with 0. Calculate the length of any rafter for all roof pitch in feet and inches. The length of the rafter. Re: Hip and Valley Rafters Perhaps the sizing problems of hip and valley rafters is caused by misreading the code. The body is creating the heel cut where the rafter will sit on top of the wall. in/L3cB8cq CIVIL ENGINEERING VIDEO PLAYLIST Related PostsIntersecting Roof Plane Rafter Calculations. Rafter Tools+ is a rafter calculator for complex roof framing angles that other roof framing calculators don't offer. Butt rafter: A smaller rafter interrupted by and joined to a butt purlin. Span Calculator for Wood Joists and Rafters also available for the Android OS. As an example, assume both F1 and F2 is 300 kilograms:. For the design of an actual structure, a competent professional should be consulted. Calculated Industries 4065: User Guide. Roofing Calculator. The jack rafters get shorter as they fan out from the center and end just before each end of the main rafter. It can seem intimidating at first, but with a roofing calculator, you can make quick work of the mathematical portion of the job. Length of beam (m, ft) Force F1 (N, lb f ) distance from R 1 (m, ft). Rafter Tools+ is a rafter calculator for complex roof framing angles that other roof framing calculators don't offer. Ive looked at the span tables posted on here but not sure what im looking at. After they're up, you can snap a line to mark and trim the tails in a nice straight line, to make up for any ridge warp or marking, cutting and fixing errors. This Dormer Shed Roof Rafter calculator will return the roof framing trigonometry & geometry details for: Dormer Shed Roof Rafter Length Dormer Shed Roof Miter Angle (Rake Cut Angle). Octagon Layout Calculator WHAT IS IT? It's a carpenter's aid for laying out a perfect octagon. The following data is standard reference and size data for commercially available lumber within the USA. To use this calculator, ﬁrst ﬁnd the total square footage of the attic ﬂoor area. The Southern Forest Products Associa -. Requirements for future 3-season porches or screen porches: a. The body is creating the heel cut where the rafter will sit on top of the wall. This is the fifth video of my estimating series. The example shows brick veneer construction (see Figure 1) the roof pitch is 20°, the rafter run is 3. Finding angles. The extended length is the distance. x 12' = 4' rise. Hip Rafter Ratio Length Multiplier HRRLM = 18 ÷ 12 = 1. This step by step diy project is about how to build a garage roof. This illustration shows an exaggerated crown to get my point across. tended rafter lengths since I used a 1-in. Use this calculator to find out the beam span and deck footing size for your project. Stair Tangent for iPhone This iPhone app is for rough frame carpenters that don't build stairs everyday, but could use an stair app calculator to check their stair building calculations. If you have any questions regarding the methodology used in WOODWEB's Lumber Weight calculator. Wood beams may be built-up or solid. A cavity closer should be provided to the top of the walls to prevent fire spread and to stop damp air entering the roof space. Our roof rafter calculator tools are handy for calculating the number of rafters needed, rafter length calculator, lineal feet of rafter, board feed in ridge and sub-facia,and the total board feet in the roof. I’m trying to find information on how to size a rafter. 3 author--steve drake Stepping Off The Length Of The Rafter Once you have the rafter tail cut for the overhang and the birds mouth now you have to calculate the length of the rafter. Increase corner footings size shown by 90%. " Laura California, United States. After, let ImproveNet help you find a local roofer. The hip and valley factor is a number that is multiplied by the actual run (horizontal distance) of a common rafter to determine the length of a hip or valley rafter. Difference in height in inches divided by run in feet = pitch. Joist Hanger Selector. Rafter Stock Size Calculator Input the rafter span (on the flat), eave overhang and pitch of the roof. Trusses are incredibly strong. Enter the value for the roof width (outside to outside) in feet, inches, and fraction, inches and fraction, or use the inches box to enter a value in decimals if that is your preference. The Struts are used to prevent the sagging of principal rafters. After building the base of the shed and fitting the wall frames, you need to continue your project by fitting the rafters and the rest of the roofing components. The ties usually rest on the joists. For RAFTER, check the height of roof and the breadth of plan to determine the rafter which is the falling portion of the roof (except is already given from the section) Lets take the height of the roof as 3. To get overall plumb to plumb length add overhang horizontal length to horizontal span. To see how pitch impacts the look of a garage and changes cost click the design center button on our pole barn kits page. Some buildings are long enough to require more than one piece of ridge material. With your ridge cut or plumb cut made you are now all set to mark out your birdsmouth. Check sources of supply for available grades and sizes, and for. Mechanical Tolerance Variations of Lumber: Per. The rafters of a hipped roof, which span between the ridge board, hip rafter or valley rafter and the wall framing top plate, may be common, hip, valley and jack rafters. Calculate the rafter length, substituting these values into the following formula:. 5mm celotex PL4000 under rafters. Joists under parallel bearing partitions shall be of adequate size to support the load. Try to promote deep root growth with your lawn. Calculate the length of a rafter from roof pitch and a length measurement. The Count Calculator allows you to define and save any number of calculator formulas that you can retrieve later and apply to other items in the same job, or in different jobs. Drill up from below at the peak, and set bolts in. Then times the pounds per sqft of live load. The plumb cut is the simplest to calculate, though it does require a scientific calculator. A roof truss calculator will help answer your roof truss questions. Width squared + rise squared = rafter length squared. Aroostook Trusses - a family owned business established in 1996. 1 to a hip/valley beam from WFCM 3. COMMONLY USED RESIDENTIAL BUILDING CODES. Then click on Calculate, to compute the other values. Pitched roof timber sizes. Calculated Industries 4065: User Guide. How to calculate the length of the above ridge: Length - Width + Ridge thickness. The Pythagorean theorem allows you to calculate the length of the hip rafter without measuring it directly, which requires you to climb onto the roof. However, I can't think of a time when we would have used this approach. and earthquakes. How to Work Out How Much Roofing You Need for Your Pergola. The material used for the ridgeboard is usually wider than the rafter stock. For the following calculations the plane of the Total Deck Angle or Plan Angle, the level plane through the Main Eave and Dormer Eave, is rotated until it contacts the Main Ridge and Dormer Ridge creating a REFERENCE PLANE for subsequent calculations. Input the rafter span (on the flat), eave overhang and pitch of the roof. JRN 1 is the first rafter after the last full rafter, 2 is the next, etc. Rafter Length Calculation: Rafter length calculation. How to Determine the Pitch for a Shed Roof Rafter. Easycalculation. This is very useful information for many purposes, especially for roof framing - the slope, sometimes called pitch, is calibrated on speed squares. The quick and easy way to get your structural calculations, accepted by Building Control Departments Select your calculation type. Welcome to OnlineConversion. If rafter construction is used instead of roof trusses, and the roof covering is regular sheeting or tiles (as already mentioned), it is important to accurately assess the parameters for rafter spans and the size and grade of rafters. If you have any questions regarding the methodology used in WOODWEB's Lumber Weight calculator. Common rafters pass over and are supported by a principal purlin, if present. T ax spans provided herein were determined on the same basis as those in the code-rec - ognized Span Tables for Joists and Rafters and Wood Structural Design Data (1986 with 1992 revisions), both published by the American Wood Council (AWC). Measure the length and width in feet, then multiply together to find the square footage. The plumb cut is the simplest to calculate, though it does require a scientific calculator. If you have a roof plan and no section through the building showing the length of the rafter, provided you know what the rafter pitch should be it is possible to calculate the rafter length from the horizontal distance from the fascia board to the ridge board. Woodworking is a popular exercise for a lot of hundreds of years. Add the length for the eaves, if needed, to the rafter length, and you have the overall length of your common rafter. Never the less, this rafter is correct in the angles and lengths. Doubled joists, sized to adequately. Rafter span tables - Use these tables to determine lengths, sizes and spacing of rafters based on a variety of factors such as, species, load, grade, spacing and pitch. A hip rafter is a rafter that runs from the end of a roof ridge to a corner of the eaves. There are also factors such as deflection, elasticity and wood species that come. This also was a sign of tremendous tension. Roof slope calculator - example of use. Magna Glulam timbers comply with the requirements of the Building Code of Australia and come with a 15-year warranty. Length of common rafter Refer to Table 15. Calculate Required Tube Size Using Structural Properties Home / Resources / Calculators / Calculate Required Tube Size Using Structural Properties The calculator can be utilized by anyone that knows the loading criteria of their application and whether the tube will be used as a beam or column. This is the rafter length from the top cut to the seat plumb mark. How To Calculate Your Rafter Length! For many people, working out the roof's rafter length can be a bit of a nightmare. After building the base of the shed and fitting the wall frames, you need to continue your project by fitting the rafters and the rest of the roofing components. How to build the lean to shed sidewall and cut roof rafters. Voluntary Product Standard PS 20-05, American Softwood Lumber Standard. The ALLJOIST® series (AJS®) I-joists have solid-sawn flanges made largely from black spruce, proven web stock and approved structural adhesives. The calculator will retun the jack rafter length difference for the main hip rafter and the valley rafter jack rafters. (on center) as the roof sheathing is span rated for 24″ O. 28 they aren't very close. 4065 Calculator pdf manual download. Calculator for adding, subtracting, multiplying and dividing feet and inches using whole numbers, mixed numbers and fractions. Using the rafter table you can determine the length of any rafter, including notching and all of the angle / odd cuts. A roof rafter is a type of internal vertical beam that holds up a building's roof load, or weight from above, and constitutes a roof's framework. SPAN TABLES - These span tables have been developed in good faith, with the assistance of Mr. How To Cut Common Rafters---Pt. Find the jack lengths, hip pitch, or common rafter length in a few simple keystrokes. CAD dwg drawing for Roof Rafter Beams Ridge Connection Detail. Wood/ timber are sawn into various sizes amongst are 2” by 2” i. Check sources of supply for available grades and sizes, and for. BEST TUTORIAL ON QUANTITY SURVEYING & ANALYSIS https://cuturl. To see how pitch impacts the look of a garage and changes cost click the design center button on our pole barn kits page. 5m and the breadth of plan plus overhang is 9m. How to Work Out How Much Roofing You Need for Your Pergola. Do not round up to the next foot. To make a birdsmouth cut, first calculate the size and orientation of the cut based on the pitch of the roof. Octagon Layout Calculator WHAT IS IT? It's a carpenter's aid for laying out a perfect octagon. Roof Pitch Calculator Results Explained. Truss Calculator Select Trusses & Lumber. The Struts are used to prevent the sagging of principal rafters. Related Products Structural Laminated Flooring. Deflection limits can be set for live load and total load. The Ontario Building Code | Spans for Joists, Rafters and Beams 9. Calculate the square footage of the room by multiplying the width of the room by its length. This roof valley is a perfect example. Find the exact value of cos 330º and sin 330º. Header size: Horizontal 2x4 size: Purlin 2x4 size: Roof felt: Truss ratio (X by Y): x. Wood columns shall not be less in nominal size than 4" x 4" IBC 2304. angle_1 was found in the hip rafter section. Not all of the possible Southern Pine grade/size combinations are produced. ridge beam simple span example no. Program for calculating the rafters for this and it is intended. Write the measure in radians. Is it calculated on total or clear span? Edit for clarification: It is purlin bracing with a strongback, aka "under-purlin" I'm trying to obtain a permit to extend my roof line over a room addition and. Roof Framing: Location of the Bird's Mouth Cutout in the Rafter. This gives me the extended length (or unadjusted length) of each rafter. For example. What size rafters do I need for a cathedral ceiling, with a 25 foot ridge and 16' width? - Answered by a verified Structural Engineer. First Method: The theoretic length of a rafter is indicated by the center lines in Figs. properly sheathed and nailed on the top edge of the joist or rafter. if you are planning to have an overhang, you'll adopt a longer rafter member. It is difficult to measure a curve with a straight-edged ruler with any kind of accuracy, but geometry provides a relatively simple way to calculate the length of an arc. Another splicing method—though it does not utilize uniform spacing—is to overlap the rafter ends that are supported by beams. Truss Calculator Select Trusses & Lumber. tail or eave Length: The tail or eave overhang must be added to the rafter length. Header size: Horizontal 2x4 size: Purlin 2x4 size: Roof felt: Truss ratio (X by Y): x. At the time of the cutting of the universal, jack and hip rafters, it is necessary that their lengths be determined by the use of a calculator/ rafter table paperback. Find its length with our online rafter length calculator. For example, if the clear distance between supports is 3m and the beam has a minimum end bearing length of 0. I’m trying to find information on how to size a rafter. 302 = Common Rafter Length ( 96") ( 125") To find the hip rafter length, multiply the Common Rafter Run by the Hip Length Factor that is given for a 10 /12 pitch. It include items such as wall partitions and services. Amazon's Choice for rafter calculator Calculated Industries 4065 Construction Master Pro Advanced Construction Math Feet-inch-Fraction Calculator for Contractors, Estimators, Builders, Framers, Remodelers, Renovators and Carpenters. "Effective Run" is the Run (Span/2) minus the ridge deduction (usually the Ridge board/2), and is the dim used to calculate the Rafter length. In case you need them, here are the Trig Triangle Formula Tables, the Triangle Angle Calculator is also available for angle only calculations. If you're building rafters and aren't sure where to start when determining the length of your lumber, you're in the right place. The length of a given jack rafter is found by first finding the x location, and then finding the length at that point. Calculating the actual length for the roof rafters can be accomplished in several ways by doing the math or by using a modern calculator designed to do this for you. Residential property for sale in Portales,NM (MLS #20192227). Requirements for future 3-season porches or screen porches: a. Select a bearing length with a maximum reaction that meets or exceeds your calculated value. When in doubt, build a double 2x12 header sandwich like we explain next. Purlin: A purlin is a horizontal piece of timber or metal which supports the roof’s rafters or decking and helps to prevent your roof from sagging. The width of the house, the height from the beginning to the roof ridge and the width of the overhang is the length of rafter calculation, the distance to the groove. A free Calculator is provided at the bottom. Commercial Lumber Sizes Chart Table. All we do now is use a calculator to multiply 1. (See figure 5 for various eave constructions. As an example, assume both F1 and F2 is 300 kilograms:. The most basic thing a roof cutter needs to know and understand is a rafter length is simply the Hypotenuse of a right triangle, and the “ER” is the base of the triangle. Measure the rise of your roof. Width squared + rise squared = rafter length squared. All prices exclude VAT at current rate and are subject to change and withdrawal without prior notice. Also for: 4080, 44080, 4065 v3. Typical Roof Truss Design Spans General Notes: 1) Spans shown in charts are in feet. I recently had a woodworking project with compound angles. For a good straight fascia, add an extra inch or 2 to the tails of all your rafters (total length). Purlin: A purlin is a horizontal piece of timber or metal which supports the roof’s rafters or decking and helps to prevent your roof from sagging. Maximum 7 rafter bars to the corner. This Dormer Shed Roof Rafter calculator will return the roof framing trigonometry & geometry details for: Dormer Shed Roof Rafter Length Dormer Shed Roof Miter Angle (Rake Cut Angle). Beam Span Calculator. IRC has no definitions for any of them. This assumes you have a rafter square Look for this table on the square's body " Length of common rafter per foot of run " For 6 in 12 pitch , look under the 6 The value is 13. Calculating the actual length for the roof rafters can be accomplished in several ways by doing the math or by using a modern calculator designed to do this for you. This is especially the case if you are going to do it yourself and try to manage it all on your own. ) Roof Base Width (in ft. What size rafters do I need for a cathedral ceiling, with a 25 foot ridge and 16' width? - Answered by a verified Structural Engineer. First Method: The theoretic length of a rafter is indicated by the center lines in Figs. The run of the rafter. How To Calculate Your Rafter Length! For many people, working out the roof’s rafter length can be a bit of a nightmare. With this Roof Pitch Calculator, you can quickly calculate the length of your gable (length of the rafters). This is the fifth video of my estimating series. ridge beam simple span example no. To get results you need to provide roof base dimensions (length and width) and roof pitch (we assume it is identical for all sides). When I was a carpenter I followed an old rule I was taught: Make the ridge and valley one size larger then the rafter; example if the rafters are 2x8 make the ridge and valley 2x10. Since the jack rafters fan out inside the main rafter at an angle, each end must be beveled in order to fit properly. You can enter dead and live loads applied to the full length of the center. Use it to calculate your gazebo layout. In case you need them, here are the Trig Triangle Formula Tables, the Triangle Angle Calculator is also available for angle only calculations. Ridge length 200mm greater than lean-to section. Residential property for sale in Portales,NM (MLS #20192227). 302 = Common Rafter Length ( 96") ( 125") To find the hip rafter length, multiply the Common Rafter Run by the Hip Length Factor that is given for a 10 /12 pitch. Use this top cord truss calculator to estimate your rake length for your next projects roof sheathing requirements. JRN 1 is the first rafter after the last full rafter, 2 is the next, etc. Excel Spreadsheet Design for Engineering Calculations I adore creating Excel spreadsheets. [Click to enlarge any image] The rafter tables allow you to calculate the length of a rafter by choosing a "full scale" number that matches the unit rise (slope or angle) of the roof. Minimum 400mm return from Victorian to lean-to. I am trying to decide on the size of the rafters and spacing and I am looking for feedback from people who have experience with their buildings. The size formula is not the same as the "regular" or traditional birdsmouth. Unlike rafters for flat roofs, rafters for pitched gable and hip roofs rise at an angle from the outside walls and meet at a ridge. Resistance to lateral and vertical actions is provided by the rigidity of the connections and the bending stiffness of the members, which is increased by a suitable haunch or deepening of the rafter sections. Again, this right triangle calculator works when you fill in 2 fields in the triangle angles, or the triangle sides. 1(1) through (8). First Method: The theoretic length of a rafter is indicated by the center lines in Figs. Select slope factor for given slope in table. Bookshop: Eurocode 5 span tables. What number times itself = 160? If you have a calculator that gives. The only way that I could imagine using a rafter cut like this is if I was making up my own roof trusses, all bolted together with bottom chords that the trusses would sit on. The roof. To calculate the length of a hip rafter, multiply the unit length by the number of feet in the total run of a common rafter. The rafters are going to span the distance of the lentils, and they're the pieces that will create the shade. Calculations to BS 5268-2: 2002 & BS 5268-7. The Length of roof sheets are manufactured to your requirements. This how-to will guide you through the steps of calculating your roof rafter correctly. Jib Crane A cantilevered or suspended beam with hoist and trolley. How To Calculate Your Rafter Length! For many people, working out the roof's rafter length can be a bit of a nightmare. 340 metre s and for an eaves width of 0. If you're using a roofing calculator, it will use the information you've already input (run measurement and pitch) to calculate the length for each rafter. 3 does say to size as beams but do builders? Usually not. com Use our online Rafter Length Calculator to quickly compute the length of the shed roof rafter by entering the measurements of overhead, length of roof span, pitch or angle. As the trusses come with a web of triangles inside the main frame. This is the fifth video of my estimating series. The ICC 1&2 Family Dwelling Code requires: That ridges, and hip and valley rafters be sized as beams ONLY for pitches of 3:12 or less. To get overall plumb to plumb length add overhang horizontal length to horizontal span. ” For example, the unit length for a unit rise of 8" is 18. While every effort has been made to insure the accuracy of the information presented, and special effort has been made to assure that the information reflects the state-of-the-art, neither the West Coast Lumber Inspection Bureau, the American Wood Council nor its members assume any responsibility for any particular design prepared from this Online Span Calculator. Determining Length Of Hip Or Valley Rafter. Curve Appeal. x 12' = 4' rise. Rafter length (along slope) = Rafter length (on the flat) x Secant of pitch where Secant = the inverse Cosine (1/Cosine) or more simply Rafter length (along slope) = Rafter length (on the flat) / Cosine of pitch. Determining the slope and skew angles related to hip and valley beams can be a challenge made even more difficult when the roof slopes on each side if the hip or valley are different. Roof slope calculator - example of use. It can seem intimidating at first, but with a roofing calculator, you can make quick work of the mathematical portion of the job. The ridge in this example would be 1. What would be the length of the roof rafters on a 16x20 shed? If you had a 4/12 pitch and the ridge was running the 20' direction and you were planning on a 12" overhang, your 2x6 rafters would be. Now that we know the formulas for finding rafter length, we need to know what angle to cut them on. He will bolt the joist to the wall or may used Long screws may be head size 12's and 4"inch length screw. 4065 Calculator pdf manual download. HIP RIDGE Rafters – Do You Know How to Calculate Them? In this computer aided age, our brain really needs some exercise – at least every once in a while. It include items such as wall partitions and services. Our rafter stock size calculator shows you how long your rafters should be, so you'll know what you need in terms of framing lumber, dimensional lumber, studs and more. EXAMPLE C1. 5m and the breadth of plan plus overhang is 9m. Snow loads must be considered for rafters, and attic storage must be taken into account for ceiling joists. tiles, battens, felt, syklights etc). When I was a carpenter I followed an old rule I was taught: Make the ridge and valley one size larger then the rafter; example if the rafters are 2x8 make the ridge and valley 2x10. 5m and the breadth of plan plus overhang is 9m. It's best to calculate heating and cooling loads with Manual J. Some buildings are long enough to require more than one piece of ridge material. 3) Top chord designed assuming structural sheathing offers lateral restraint. And by getting the prices of wood from your local home improvement store, you will know the exact cost of your roof project. Download Rafter Length Calculator apk 2. In this article I will try to show you how to design a simple "Hip Roof Garage Building" and "Standard Gable Roof Garage Building" and try to show the component parts that make up a "equal pitch hip roof" structure using the "double cheek cut hip rafter method" used by most framers today. All the figures are based on roofing tiles or slates laid on timber laths over sarking felt. Minimum 400mm return from Victorian to lean-to. You can also visit the contractor's desk at most any lumberyard and ask them to size the framing members based on your blueprints or drawings. CALCULATE VERTICAL LOADS. Click the button to calculate the stock size needed for this job. Unlike rafters for flat roofs, rafters for pitched gable and hip roofs rise at an angle from the outside walls and meet at a ridge. Includes result for hip/valley factor, slope factor and the roof angle in degrees If using a ridge board subtract half its width from the rafter length. Enter the length of the main beam span.