Concrete pad for steel supporting pillars adjacent to external wall

[Jeffers_S13]

Planning to re-roof a building I own. I want structural ridge beam to support the roof thus achieving vaulted ceiling so gaining lots of lovely open space. Architect has employed engineer to design a goal post steel type arrangement. The ridge beam being supported on two vertical steels at each side against existing walls.

The engineer has simply drawn 750x750x600 square pads centered on the vertical steels. This mean the pads need to somehow overlap into the existing walls.

It's an old building on corbelled footings, 9" thick solid wall, no cavity. The pad would extend beyond the outer face of the wall and just about touches the upper course of the four course corbelling.

Simple question, how do I construct such an arrangement?

 

[Paulg31]

Ask your Structural Engineer, they should have considered buildability.

 

[tony1851]

The ground area covered will be 0.56 m². Ask the SE if you can do a narrower but longer pad of equivalent ground-bearing area.
Depends on the shape of the base plate; too narrow a pad will compromise the fixings.
As above, your SE should really be advising you on this - that's what you pay them for.

 

[Jeffers_S13]

Exactly what I thought, SE says it's not his problem he wouldn't get involved. I should ask a builder how they'd put it in. His job is to do calcs to support a roof and that's it he said!

 

[cdbe]

Presumably you'd just go under the wall? No propping required for 750mm. If it's an old solid wall then probably not much under the brickwork that can't be got out. If the pad is too high up the external wall can't it be installed lower with a slightly longer post?

 

[^woody^]

It's an engineering solution related to the frame he has designed, so it is his problem.

 

[Jeffers_S13]

So I should excavate all the way to the underside of the corbelling and put the pad under the bottom of it? I will need to remove some of the bricks on the inside corbelling to allow the steel to sit flush against the wall?

 

[cdbe]

Maybe your engineer will be able to do something, maybe an offset pad, cranked post or something that sits away from the wall with packers/brackets to fasten it to the wall, all way beyond me and sounds far more complicated than a bit of digging and bashing out a few bricks - but I like digging and bashing out bricks!