Cantilevered joists of an I beam question

[George_engineer]

It's not a great detail.

Can you elaborate more on this bit

Due to my design requirements I need the top frame of the S door to be higher than the beam.

Could this be better addressed by using a shallower beam

 

[TimB100]

These are the issues I have to deal with

1 The extension limits the height of the structure to 3mtrs. The original kitchen is stepped down to so I want to raise the floor. Add that to the level of the ground out the back being again lower I am very limited in ceiling height head room. I cannot just lower the ceiling.
2 Its a cold roof and the beam is calculated already. At 225 tall is not really big
3 To get the frameless look the sliding door frame needs to be mounted ~60-100mm higher than the ceiling level see image

I'm pretty sure now that the bolting of 200mm of timber to the frame is the solution. The timber will be also supported at each end by the wall. This will reduce greatly any twisting motion

 

[blup]

Could you fix through the deck which would have a cantilever support effect in addition to any brackets in the web

 

[TimB100]

blup

The design is now such there there is not much cantilevering. What there is is being taken up by the bolts which I may add to higher in the beam web. If need be I can add a strap across the from the joist to the blocks. I also have to factor in a hidden gutter system.
Personally I would not use the decking to counter the leverage forces.
I'm going to make a comprehensive file of all the building subtleties with my own drawings that I'm not sure about and get the building inspector round to go over them and say yay or nay and what he/she will wants.

Tim

 

[robinbanks]

All this to achieve a recess of what.. 2 inches?

When you're done with the structural finagling, you'll need to switch to considering how you'll insulate that beam..

What size opening is it spanning?

 

[TimB100]

"All this to achieve a recess of what.. 2 inches?"
60-100mm is more like 3-4 inches

If I mount the frame to the beam whats the R value and how do you insulate it?? I'm pretty sure steel and wood is less insulating than just wood. You know like all the other joists.

Opening is 5mtrs

 

[George_engineer]

These are the issues I have to deal with

1 The extension limits the height of the structure to 3mtrs. The original kitchen is stepped down to so I want to raise the floor. Add that to the level of the ground out the back being again lower I am very limited in ceiling height head room. I cannot just lower the ceiling.
2 Its a cold roof and the beam is calculated already. At 225 tall is not really big
3 To get the frameless look the sliding door frame needs to be mounted ~60-100mm higher than the ceiling level see image

I'm pretty sure now that the bolting of 200mm of timber to the frame is the solution. The timber will be also supported at each end by the wall. This will reduce greatly any twisting motion

View attachment 332631

Might be worth checking is a 152x152 UC can work. That would get you 75mm back.

 

[catlad]

Warm or cold roof? Can you not get your timber firings to help with the cantilevering bit?
say finish with a 2x2"

 

[TimB100]

The design has moved on now the claterlivering is now just about done. I have all the design now sorted including the guttering behind the facia

 

[robinbanks]

Could probably do away with the steel now you've got 5 glulams compounded together over the doors; the roof structure doesn't appear to be particularly heavy
Also reduces the thermal bridge problem the steel introduces

If you're keeping the steel, insulate the top flange as best you can

 

[noseall]

The design has moved on now the claterlivering is now just about done. I have all the design now sorted including the guttering behind the facia

View attachment 332736View attachment 332737

What are you building? A garge forecourt?