How to calculate a ridge beam for a vaulted roof

Get instant results with this quick and easy method to calculate a ridge beam size using simple maths and the FREE download here: geni.us/timbercalculation
You might think that it would be difficult to do your own ridge beam calculation. But after years as a practicing structural engineer I have devised easy methods for beam calculations that you're going to be totally amazed by. You won't believe how easy it is after a couple of practice tries.
A ridge beam is needed to support a vaulted or cathederal roof.
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This video is for entertainment purposes only. Get a structural engineer involved if you are building or altering loadbearing structure.

[@RobindeJongh]

💥Get my free timber calculation reference tables: geni.us/timbercalculation

[@EmYyM87]

I have been a Civil Engineer Collage Student 10 years ago but the way he said it was so fine, sounded so familiar, had a lot to learn because I was always having some struggles when to calculate the strength of materials.and with the momentum same thing, his explanation was so good..and if I want to go forward with this I need to learn more from people like him. Many thanks and God bless.

[@asif530]

Hey Robin. This is absolutely great. You have indeed made it much easier. Much appreciated

[@zachtobin1136]

I'm no mathematician but could follow along easily with your clear instructions. Thanks a million.

[@RobindeJongh]

Thanks Zach, that's what I like to hear! 👍

[@Eamonnmhac]

really helpful and easy to follow , thanks Robin

[@Pratibhinbh]

Excellent. have been looking for this. Thanks

[@PaulGrosvenor1]

Another great video. Thanks!

[@martinlouden9005]

Thanks Robin. Great info.The download will come in very handy.

[@RobindeJongh]

Thanks Martin!

[@jamesjosephkerry7079]

Wonderful stuff ! Good on you buddy

[@midlandlongroad]

thank you an excellent explanation.

[@RobindeJongh]

You are welcome!

[@johnw614]

Robin Nice job at the beginning of a calculation for a beam. Please add a comment about checking for shear in addition to deflection, along with bearing area, lateral bracing, and end restraints for twisting of the beam as well. Viewing the comments here, many DIYers are taking this as, this is all there is to a beam calculation, when it is only just the beginning.

[@mrmechanical3423]

Hi Robin, another great video! I'd love to see a similar video but for a hip member!

[@timothyjunior8574]

Thank you

[@Jazzfinga]

Really informative, cool , thanks , I struggling with the maths a little and wondered if I can use the charts for a span of 11m ? for a timber laminated ridge beam?

[@Michael-T-G-ps110]

Thanks for these videos they are brilliant! Quick question in regards to this how do you work out the ridge beam size when putting on a dormer say for instance?

[@leem6906]

Great video Robin, clear and concise explanation. Any chance doing a video for steel box frames and/or steel goal posts calculations i.e. for removing existing ground floor rear walls/for installation of bi-fold doors from party wall to party wall. Thanks

[@RobindeJongh]

Hi Lee - yes, try this video kzbin.info/www/bejne/j2iaaaebZtZsotE and this video kzbin.info/www/bejne/kIqUq4h5br1oeLs

[@Domaso111]

Hi Robin, any chance for Z(required) values of LVL (laminated veneer lumber)? C24 is great, but for longer than spans, it becomes too massive...

[@ltet1980]

Good video. Any chance of doing one for the ridge beam on a large dormer loft conversion? Trying to plan a 7m dormer and struggling to find videos like this for that project.

[@paulbishop2161]

Thanks for the excellent video and resources! I just wish the table included 300mm or more beams, any chance of an update?

[@martywillms3838]

Hi Robin, thanks, I really enjoy your videos. I live in the US but while I was at school there was a push to switch from English Units to SI. Quick question: How do you deal with thrust component of roof rafter in tributary portion going to walls? Would you need to design the ridge to support full width of roof to avoid out of plane forces in wall? Thanks again!

[@ComeWhatThey]

Hi, thanks for the videos. I assume this calculation would only apply to a simple pitched roof where the forces are equal on each side, and would not work if there was a dormer on one side?

[@morosmith8710]

Hi Robin, can you do calculations for a couple of truss elements please

[@BackyardMechCon]

Great video. Does the 2kn/m2 loading cover all roof type materials commonly used in the UK? Would the differences between each type be negligible in this overall figure? Ie natural slate vs manufactured slate or tiles, thickness of rafters, battons, etc.

[@RobindeJongh]

Great question! Yes, it's a pretty safe and conservative loading figure for most cases in the UK. Generally you would do a detailed loading calculation first, and then you would be able to reduce this fugure if you needed to.

[@MarkBloodsport]

Great video. Very helpful. Are these calculations for a vaulted ceiling? Although your sketches show a vaulted ceiling you never said so but you made no mention of joists or collar ties in this video either, so I just wanted to be sure! Sorry if that sounds pedantic, I was wondering if these beam calculations would be sufficient to stop my walls from splaying out! Thanks again for a great bit of information.

[@RobindeJongh]

Correct - see kzbin.info/www/bejne/eKXWi55mirdle6s

[@dazhornblower5719]

Hi mate, thanks for the calculations and the tables. I wonder if you can help me though…I am tying to calculate a roof that’s 6.5 wide with the centre being 4.5 long. I have done the sums and I am getting a figure for Z being around 90. I have worked out that I would need quite a substantial flitch beam from another of your videos. I have decided that a box profiled beam is my best and i think that I have worked out that a 160x80x6.3 is sufficient but cannot find a definitive F value. Do you have a video that you can point me in the direction of please?

[@thequietroom3991]

Hi Robin, have you got any info on fixing either end if the beam to the existing building and new gable end. Would BI need to see a pad stone on tbe gable end? Is the existing end fixed to diagonal wall plates in some way?

[@RobindeJongh]

Ridge beams (if steel) typically go onto padstones. Timber beams usually don't need padstones. It's checked with a bearing calculation.

[@ubermenschen3636]

@12:44, you need to calculate the Z using allowable compression and tension stress values as these two are not the same. Then use the larger Z value to select the dimensional lumber.

[@usstotts]

Hi, I have had a look at your course and will be buying this as a refresher from when I did simply supported beams at college. Do you intend to do a course including post, foundations, small frames. I have my our architectural business (one man band) but qualified as a building surveyor. I do do simple beam calcs but would like the reassurance from your course but would eventually like to do calculations for small frames. Hope you intend to expand to include this. Andy

[@RobindeJongh]

Hi Andy. If there's demand for this first course I will certainly look at further courses covering columns, foundations and steel frames, as others have asked for these topics as well. Look forward to seeing you inside the Steel Beam Beginner's Guide course!

[@jlynch442]

Great video! Does the roof pitch matter in these calculations?

[@RobindeJongh]

Hi James. You're correct, it does. The dead load increases the larger the pitch. That's worked out when you decide on the loadings.

[@shelbyalexander6446]

Hi Robin, Thanks for the video very useful and informative. Ive done some calculations for a roof which I'm planning myself which is 6.6m from wall plate to wall plate and 5m in length from building to gable end so 5m ridge length. Moment is 20.625 KNM and 6.6kn/m UDL so I've calculated a Z req of 2746 x 10power3 . It seems the tables would require a huge beam in timber would it be more achievable using steel ? Do you have a steel beam calculator ?

[@DSkimRS]

my guess from extrapolating with figures provided in tables would be 2pcs of 350x100 i.e. 350x200 for z value approx 3k

[@RobindeJongh]

Hi Shelby. Try the free video here kzbin.info/www/bejne/g4fNpo17fJKVhpY or for in depth training, my steel beam course: structural.thinkific.com/courses/steel-beam-calculations

[@thepeginator2556]

Does this still apply in an instance where you aren’t using rafters? E.g. a roof using SIPs / insulated box profile where the panels themselves provide the structure between the ridge and the wall plate? I assume it’s still possible but the loadings might be calculated differently. In my case I want to build a 6x4.2m workshop using SIPs for the walls and insulated box profile for the roof covering, just wondering what size of ridge beam I’d need if I wanted to avoid using trusses. I’m guessing a pretty big one as 6m is a fair old span.

[@RobindeJongh]

It's the same principle with SIPS or box profile. For a 6m span you would need a steel beam.

[@joethomas2794]

Thanks for this, really useful. I'm planning a vaulted roof, 5m span, 7m length. The Zreq I get is 4093,333 (4093). Nothing like that on the table you mention, would it be a combination of several (eg 4x 250x100)? Or, any other advice/suggestions for that length/span? Glulam? Larger single beam?

[@RobindeJongh]

Hi Joe. I can probably suggest a beam size for you. I do ask for a small donation when dealing with larger questions like this as it takes a little more time: geni.us/askrobin

[@christopherpalmer4243]

I'm building a 8x8 metre flat roof casa. I want to add a thacketed hip roof. It's a SIP panel house. Can I just build it straight on the roof?

[@dancingfrogsxb1276]

If a calculate my rafters then my purlins, do I then calculate the ridge beam from the ridge to the first purlin? Or is it more elaborate than that?

[@RobindeJongh]

In theory, the purlins and ridge beam should all take the same amount of load. In practice, if the purlins are more flexible, more load will be attracted to the ridge beam and wallplate.

[@judegraham463]

dear Robin. Are these calculations possible on a computer keyboard. I cant figure out what the your calculators 'shift' symbol is on my computer keyboard. I've tried doing this simple calculation but to no avail., My 'moment' is '64, and x by 10 power of 6, dividing by 7.5, and I get -6.2. I have tried many variations on my keyboard but cant find the right key to press. Please help. Thanks robin.

[@RobindeJongh]

Hi Jude. You can multiply by 1,000,000 as this will do the same thing.

[@Burritosarebetterthantacos]

This made me think twice about adding a faux beam to my vaulted ceiling ridge😮

[@vikingqc4045]

When do you have to double a LVL for a R beam

[@phrdcstl]

Great video.. but how does the timber chart convert to steel? 🤔

[@fitzgm1]

Hey Robin, I've the same question, you don't have a version of that chart for steel ridge perlin?

[@dugbert9]

I felt like a genius as I followed along then got stuck when my calculations didn't work. My room is 6.5m long and 4m wide but maybe I'll just build it 3m x 3m so I can use your example

[@obscuredvisionary]

I'm confused, shouldn't it be 1.5m x 3m = 4.5m^2 x 2kn/m^2 = 4.5N UDL (m^2 cancels out leaving w in Newtons)

[@dugbert9]

not sure what voodoo yoru calculator is doing but I cannot get the same result as you with the same inputs. I'm using a scientific calculator on my iphone but cannot get the same result. When you input a 6 after the 10* do you add it, multiply it???

[@RobindeJongh]

Hi. Doing ten to the power of six is the same as multiplying by 1000000, i.e. 1 and 6 zeros. Iphone calculators has a funny way of doing it - not sure I would rely on that!

[@kylecampbell586]

More importantly than simplifying the math the code can change from state to state county to county and the same for Canada where we have province county and village so if your going to provide a video ether provide where the video is from or where it's applicable by law as building codes very widely

[@samuelochieng6247]

please do a complete design for a vaulted roof, from loading to all member sizing.

[@RobindeJongh]

Hi Samuel. Thanks for your suggestion 👍

[@codyabel4766]

at 5:45you say it is equal to 3. why is it equal to 3? you have chosen 3x3 and 3 meters load. there are 3 different 3's and you've not explained which one you are using here. i can't transfer this to my own numbers bc i dont know what to substitute from my own project; length, width or one side of effective load area. gonna look for another video but thank you for the intro

[@RobindeJongh]

Hi Cody. Because the sum 1.5 * 2 = 3

[@brittofc5388]

Hi Robin, Can we pay for the course with PayPal? Thanks

[@RobindeJongh]

Yes you can pay by paypal or any credit or debit card.

[@brittofc5388]

@@RobindeJongh That's great thanks, Will you be doing a retaining wall course like this as well?

[@RobindeJongh]

@@brittofc5388 Sure, if there's demand for it - what kind of retaining wall are you thinking of?

[@brittofc5388]

@@RobindeJongh Any really, Gabion, masonry, Cantilever, gravity, steel reinforced?

[@codyabel4766]

love the video but WHY did you choose 3 for everything. might as well choose x to represent multiple different values!!!

[@RobindeJongh]

Hi Cody. I see your point! If you look at what units I'm using, you can see whether each "3" is a load or dimension.

[@jstephan03]

Is there ever a need for a safety factor?

[@RobindeJongh]

Yes. With timber design to British Standards, the "allowable stress" already has a factor of safety in it.

[@steveksi]

Did I miss it, but hasn't the roof pitch got anything to do with it.

[@AfricanSouthernCross]

Very very complicated method of explanation, you can get a far easier method on other channels.