steel beam

10 Jan 2007
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United Kingdom
I've fitted a steelbeam which is a 6mm steel box section 150wide x 250 high with a 10mm plate 250mm wide welded to the bottom over my bi fold doors at a rear lean to extension.The beam is 5m long and i've sat it on a padstone at each end ,the beam is parallel with the wall so the box section sits on the padstone and the front of the 10mm plate sits on the brickwork outside.I've sat the beam on the padstones with a bearing of 150mm is that enough?
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Engineers drawing just said 5m span which is what the opening is and all the workings out nothing about length of beam.Theres 1.5m of blockwork both sides of doors and the padstones are sitting on 2 engineering bricks and then blockwork below that.The beam is carrying wallplate, trusses and roof tiles.Just need to put my mind at rest really.BCO came out the other day and he never said anything about it.Maybe i'm worrying over nothing.
99% of the time 150mm is adequate (I don't recall a job where it wasn't) I recall (the odd times I've actually glanced at the calcs) there will be reference to the bearing in the calcs somewhere. If you're that worried ring your SE.
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I have seen a steel beam carrying two individual floor loads, laid on no more than 50mm of friable block, with no ill effects.
The house went up in the late '50s , so has had chance to 'settle' somewhat.:cool:

150mm seems like acres in comparison.
The padstone is 440x215x100 and the beam is sitting in line with the 440 length so it is sitting on 150 and there is 290 of the padstone remaining.
I'd bet a year's money you will never have a problem with this, as people have said.
Yes you are worrying about nothing! Now stop it :mrgreen:
150mm could be adequate however if you want me to confirm more detail is needed;-

1) sounds like the beam is supporting a single storey roof. What span are the trusses which are supported by the beam

2) Is there any masonry supported or is wallplate fixed to top of ox section? How many courses of brick outer leaf are supported?

3) What is compressive strength of concrete blocks (2.8N)?

4) What mortar mix has been used


150mm bearing is definitely enough, as you will be bearing onto something like 20N/mm ² concrete minimum. No doubt about it.

Whether or not the 450mm padstone is large enough to spread the load onto the masonry below is another matter. I'd guess that it is, but there's no way of knowing as you haven't given us the information that we need to work out the bearing pressures and capacity.
The span of the trusses is 3.8m and the top of the box section has got the wallplate hiltied to it.The outer plate just has the soffit sitting on it,the blockwork is durox 3.6n supabloc and the mortar is the readymix 6:1:1.
Thanks guys.

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