Steel Beam wider than Cavity Wall - Extension

[dc25]

Hi

Currently have a builder doing an extension on my home and it requires a 305 steel being installed on posts.
My aim/instruction was to 'hide' the beam but putting it higher in the property and the floor joists will then run into it.
We have a 305mm steel beam but the cavity wall is 1980s and approx 250mm wide so there will be an overlap or bulkhead somewhere.
I want this to be external for obvious reasons but now I think there will be an awkward detail/bulkhead in the new extension (especially with a vaulted ceiling)

How would this detail work in reality? Any ideas on how to cover this/hide it?

I can share current plans etc if needed.

Thanks

 

[freddiemercurystwin]

305 is typical for a height not a width of a steel beam, are you sure it's 305 wide? That would be an absolute monster for a domestic installation.

 

[dc25]

 

[dc25]

305 is typical for a height not a width of a steel beam, are you sure it's 305 wide? That would be an absolute monster for a domestic installation.

This is the steel size proposed

 

[freddiemercurystwin]

Image no worky.

 

[dc25]

Image no worky.

 

[freddiemercurystwin]

Holy Cow! How big is the span, is your engineer on drugs? Did he not know how wide your wall was? Often two smaller beams can be used which saves the builder some stress too.

 

[dc25]

Holy Cow! How big is the span, is your engineer on drugs? Did he not know how wide your wall was? Often two smaller beams can be used which saves the builder some stress too.

I spoke to the structural engineers and the clear opening width would need to be reduced to 5100mm (Currently 5480mm) in order to get it to work as 2No 254 UBs. I didn't want a pier to reduce the opening to 5100mm. The width of the wall wasn't confirmed (Architect wasn't very good) and now we're left with this awkward detail.

 

[tony1851]

A 305 x 305 on that span was ridiculous.
There is the smaller option of a 254 x 254 which would have done, or even a 203 x 203 with a 250 x 6 plate tack-welded on top to pick up the cavity wall.
To specify a 305 x 305 for domestic loading on that span is not engineering, its just lazyness.
But what's done is done.
As it overhangs the wall on the extension-side, can you batten out the wall above and plasterboard it to make it flush? Ditto on the internal side?

 

[kp00110]

If the opening is over 5m wide, I doubt much wall must be left either side if the opening? If the issue is the 50mm or so step, can't you just pack out the rest of the wall below the steel beam 50mm say with insulated plasterboard etc or stud etc to bring wall out to face of steel beam? I imagine posts are the same width as beam so wall would also run nicely and hide posts then

 

[jeds]

You see some ridiculous beams specified, but this takes the biscuit. In fact, a full packet of chocolate hobnobs. I would seriously consider going to another engineer for a sensible beam calculation.

Edit; post the calculation details. I'd love to see them.

 

[Benway]

Had the same issue. Well we had 2 steels when butted against each other were wider than the wall.
I assume it's a cavity wall? Ask them to design with 2 steels. And give them the existing wall dimensions and state needs to fit with these measurements. Good luck. I ended up using an online calculator to spec the steels.

 

[dc25]

You see some ridiculous beams specified, but this takes the biscuit. In fact, a full packet of chocolate hobnobs. I would seriously consider going to another engineer for a sensible beam calculation.

Edit; post the calculation details. I'd love to see them.

Had the same issue. Well we had 2 steels when butted against each other were wider than the wall.
I assume it's a cavity wall? Ask them to design with 2 steels. And give them the existing wall dimensions and state needs to fit with these measurements. Good luck. I ended up using an online calculator to spec the steels.

Do you have a detail or drawing of how this looked?

 

[Benway]

Had a thread here https://www.diynot.com/diy/threads/steel-bean-cavity-wall-sizes.478881/

Ended up using narrower, taller steels

Beam Details Beam Span Length = 5.76m Steel Beam Selected = 305 x 127 x 48 UB S275

Which is a little over the 100mm brick width, but only (127-100/2) 13.5mm either side so is easily accomdated.

Ouside view

Inside view