Steel beam size question

[Inspector]

So that would be eves hight max 2.5m and ridge max 4m right? so 2.5m away from a border. My garden is only 11m wide and im planning on putting another building side by side so mine is only 40cm away from a boarder. However i love this roof type and dont want to go down the flat roof option

I was wondering why build two structures side by side? To my little mind it would make more sense to make one larger building, divided down the middle so the need for a ridge beam is eliminated entirely because all the rafters can sit on top of the middle wall. Construction is simplified. Less materials needed since you are not duplicating walls. You don't have the issues of putting siding up between them assuming they are close together. Your porch would be wider if desired.

Pete

 

[deema]

I’m with @Inspector, my build is 1500 sq feet externally all within permitted development rules.

 

[Fergie 307]

I was wondering why build two structures side by side? To my little mind it would make more sense to make one larger building, divided down the middle so the need for a ridge beam is eliminated entirely because all the rafters can sit on top of the middle wall. Construction is simplified. Less materials needed since you are not duplicating walls. You don't have the issues of putting siding up between them assuming they are close together. Your porch would be wider if desired.

Pete

I did exactly what Pete described some years ago. In my case the constraint being money, or a lack of it!
I built one half as a pent roof, then later added the other half so ended up with a large span shallow pitch with the joists supported on the centre wall.

 

[Dave Moore]

Hi,
Why not have a flat roof , osb and rubber covering with a warm roof. Simpler and rubber guaranteed 30 yrs.
Regards,
Dave

 

[TomGW]

Like this?
View attachment 176728

Yes. Now you've got more strength in the ridge and the supporting lintel.

 

[TomGW]

Like this?
View attachment 176699

Need a way now to achieve the clean roof line now like this =/
View attachment 176700

Yes, that's what I had in mind. Also glue the ridge beam (& lintel) sandwiches together for added strength - think glulam beams.

 

[TomGW]

An alternative approach would be to span directly from side to side with deep joists, tapered off on both sides to form a low pitch and ridge. If you cut the taper triangle from the outer quarters they can be reversed as furring pieces on the middle to create your pitch.
This will dispense with the ridge beam altogether and place no load at all on top of your door opening. It will also totally remove the potential for the roof structure to splay the walls, as it's tied directly through.
You could continue this or build a 'verge ladder' for the overhang at the front.

 

[Sheptonphil]

So that would be eves hight max 2.5m and ridge max 4m right? so 2.5m away from a border. My garden is only 11m wide and im planning on putting another building side by side so mine is only 40cm away from a boarder. However i love this roof type and dont want to go down the flat roof option

Just apply for planning, it’s not expensive or onerous for a small outbuilding. I did with my worship and had a decent pitch and 4m height. Sub 1m from boundary.

 

[MF1000]

You could consider using a wood I beam for the roof ….much lighter and with good strength

https://elliotts.uk/ideas-and-advice/i-joist-faqs

 

[yacobwood]

To answer a few questions. Im doing two buildings as the second will come a number of years later due to cost contraints.
I have now upped the slope on the apex roof to 10 degress with collar ties in the top 3rd and a flitch plate beam over the doorway. This should hopefully eliviate the potential for splaying

 

[Agent_zed]

if you are worried about splay but want to keep a more open look inside, you could always add some hi-tensile cables across to hold the 2 sides together. would be a fraction of the size of a wooden joist and arguably better suited, as wood is better in compression than tension.

My inlaws-to-be have an old farmhouse and the attic room is big old timbers and to be able to remove the cross members to allow an open room steel rods (about 1inch dia) criss cross the span to prevent the roof splaying out. That is a huge heavy tiled roof that is 20ft+ across

Edit - weird when you mention something and then by chance see that exact thing. Stumbled across this on a completely unrelated website. You can see how few ties are required for a huge roof.

 

[Ozcabs]

Like this?
View attachment 176728

If you don’t mind me asking, what software are you using?
X-battening is the correct way to clad vertical timber - not only to aid air flow but also reduce the smallest amount of water being drawn into the building (as it’ll sit on a horizontal batten).
Studs, rafters and floor all good.
As someone else said, based on 2m opening you’ll be fine IMO. A structural engineer will always spec up unless you know them

 

[yacobwood]

If you don’t mind me asking, what software are you using?
X-battening is the correct way to clad vertical timber - not only to aid air flow but also reduce the smallest amount of water being drawn into the building (as it’ll sit on a horizontal batten).
Studs, rafters and floor all good.
As someone else said, based on 2m opening you’ll be fine IMO. A structural engineer will always spec up unless you know them

Im just using Sketchup for the 3D modeling. Ill look into x-battening

 

[MikeJhn]

IMO it would be beneficial to construct the door frame as a separate structure, supported off pads on the ground, this way the roof loading will not impact on the doors.

Don't like those joist hangers, they rely on the shear value of the nails to support the joists, much better to use wrap over joist hangers and the correct twisted square grip nails.

 

[yacobwood]

IMO it would be beneficial to construct the door frame as a separate structure, supported off pads on the ground, this way the roof loading will not impact on the doors.

Don't like those joist hangers, they rely on the shear value of the nails to support the joists, much better to use wrap over joist hangers and the correct twisted square grip nails.

Good call. Ive changed them to these; https://www.tcfixings.co.uk/product/simpson-jha45075-long-leg-joist-hanger-75mm/2648

 

[MikeJhn]

Good call. Ive changed them to these; https://www.tcfixings.co.uk/product/simpson-jha45075-long-leg-joist-hanger-75mm/2648

Much better, do get the correct square twisted nails to fix them as well.

Give some thought to the independent door frame, could save a lot of hassle in the long run.