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Moment connection not as clear as shear one though, should have illustrated moment connection as end connection too

This is a brilliant video explanation of the how to deal with the horizontal thrust in a vaulted ceiling, explained in simple lay-mans terms. Well done Robin, great video. (from Chartered Structural Engineer +20 years exp).

should we use a hellicopter to get hieght

I work in Engineering, and if I had to build my own roof trusses, I built them out of steel box section, with welded mitre corners that are also gusseted. But then, that would be overkill.

Crazy, funny, useless video :D. If you're building a house from sticks and shit, then it's ok. First of all, before starting to build a roof, you have to build a tied up monolithic (reinforced concrete) ring all over the perimeter of walls, which will resist the expansion of walls on loads. All configurations of roofs have a right to live, but which one is good for you - only qualified engineers can calculate. In general, if one edge of a roof is not longer than 6m - it's enough A configuration. If more than 6m (A+Y or A+H), everything bigger than 10m (1/2 roof) - has to be calculated... p.s. how can you tie both ends of a roof if distance between them 14, 16, 18m? That piece of wood would bend from it's own weight....and take your roof down with it :D

Engineered "scissor" trusses. Two different pitches, one outside, one inside.

Great use of sketchup

In the case of a shear connection, when a gusset plate is provided below the beam for bracing, will that gusset plate act like a haunch for the beam?

Excellent explanation, I actually understood it first time which makes this video unique, thanks.

Its awfull that you need a structural engineer even though hes just going to look at joist span table... yet you can build a whole house no structural engineer.... WTF 🤣😂

In one rough cut garage from 60+ years ago, it's a regular wood framed wall studs, and as you showed with plywood, it was done with boards. 1x8" boards. Both sides. Rows and rows of wood. I'm amazed at the strength of a beam, created with nails, and wood, where it's boards nailed to studs.

Sorry but i cannot see how a steel ridge beam would have any affect on the load spreading action at the top plate of the walls. It would just add weight.

The software used to illustrate the points in this video looks really nice. What is it called?

Steel is the only thing that they can use in uk to support a roof😂😂

Good job demonstrating the steel ridge beam!! lol. Back up what you’re saying . All that to tell us what you recommend and not show us the proof

Cheapest solution: Ships ladder or spiral stair case... What I would do: I'd add 4 Dormers to the attic to make the room more usable, one at the stair top

Z = b*d^2/4. What you have used is S. Its safer as it assume a triangular distribution of stress. But in that particular concept, Z is the right choice.

Please what software do you use for your 3d modelling? I like the presentation of the models, it looks hand drawn.

Are you using factored loads?

Ridiculous

Hi Robin, should purlin supports mirrored / symmetrical? Wondering if it's feasible to have both purlin supports positioned opposite eachother, but slightly off of the structural mid point? Thank you for all the great content you upload !

My 100 year-old house wasn't thrown-together with bird's mouth's on the rafters. It has hand-cut WOODEN "tie-plates" on each side of them and about a dozen 22 or 24 penny nails to the DOUBLED full 2x4 inch headers. It's 100% framed in termite-proof loblolly pine (harder than 7500 psi concrete now) and wasn't even 1000 sq. ft. It wouldn't do for me to build (or contract) for a house. No "Big-Box" store "whitewood" framing and other crap for me! I'd probably get a metal building put-up and "prettied" into looking like a house. We have tornadoes har' in Okra-Homer...

The winder at the top is dangerous and it doesn't meet code in Canada. A landing is safer and will require more space. Another solution would be a dormer in the roof to get more headroom at top of stairs, of course a lot more work. Also could put the stairs on the outside to not loose space in the house. Plan ahead and build safe!

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???

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

The collar tie does work however you failed to demonstrate it correctly in order for a collar tie to be set 2 3rds up from wall plate then the timber will also need to be 2 3rds deeper or closer to the higher stock size ie if the rafter meets requirements at 2x4 you'll need to use 2x6 minimum to use a collar tie personally I over kill and double the required stick so would use 2x8 in this example, point been conduct your tests accurately and not in a way that proves your own narrative, only shop bought sheds use 1.5x1.5 scat timbers which is what your using

You simply use larger trusses and perlins, depending on the span of the rafters will determine the number of perlins, size of trusses etc. Large truss and perlins look beautiful with vaulted ceilings inbetween Another option is if doing an attic conversion, the new floor becomes the tie, tieing the walls together. Simple stuff, but always best to get a structural engineer to calculate timber dimensions that are needed

That's what collar ties are for,obviously he's not a framer,or c.j.'s ,whatever,like I said collar ties,

Is there a reason for taking the purlin out? I'm currently doing my own loft conversion, and was looking at leaving the purlin in and then putting a glulam beneath to take the new floor

Triangulation it’s called

Nice walk though, what software are you using? I love the flexibility it offers.

Amazing videos! Would you be able to do a video on how sinking steels for dormer work? With reverse firrings to add height?

you have to cross your ceiling joist to the opposite side of the ridge you go from the top of the right side rafter down to the left side plate and opposite the other side and fasten the rafters to the ceiling joist top and bottom and the roof and walls are locked out with no steel needed. It is like a scissor truss.

Scissor trusses are another option if you don't need a completely full vaulted ceiling.

Wait how does the beam you suggested at the end fix this? I assume that beam must be supported at both ends then? So the the majority of the load is basically hanging on that beam?

So the brown beam is a steel beam?

You are the MAN. I am going to do this myself.

The problem is that the steel beam won't hover either.

Throw on a full roof and shingles. Doesn’t anyone understand triangles are rigid?

And u know charts for imperial units

Thank you Robin

This is often screwed up by carpenters, especially in garages (all in usa). our. Garage was retrofitted with a large beam to halt the roofcollapse.

Or, use engineered trusses. The bottom won’t be quite as vaulted but will still give that effect.

Thanks for the detailed video! Can't fault your structural work :) However I do have some questions about the insulation, please. Modern building regs require a U-Value of 0.16 in England and Wales and Northern Ireland (for retrofit, it's higher for new build and in Scotland), so if the floor of the loft is insulated, then you need to leave space for that. The most common mineral wool (k value of 0.044) would require a depth of 270mm, plus the BBA recommends an air-gap of 50mm above that to allow air to flow from eave-to-eave, to prevent condensation forming on the bottom of the boards. So, just as a suggestion, perhaps either your calculator tool should have a minimum height of 220mm, or if someone wants less than that, there could be a warning flag up to say that a higher grade of insulation is required or that under-rafter insulation should be used instead, to make it a warm loft with the eaves sealed? What do you think? Cheers :)

When you have to watch a bunch of other videos just to understand half of what this video said 😂

Great video. If you could answer to some of my queries, it would be of great help. Should the plan bracings and vertical bracings be in the same bay? If there are no gable columns, how the plan and vertical bracing is done? Can we provide eaves beam in place of vertical bracings? Thanks.

Triangles are the strongest shape in construction.

Yes it was 25.5kN/m, I see you picked that up after, that would have changed your beam size then!? Your notations help!!

I can't believe what I see

What if the purlin is supported by a stack of bricks?