Is it acceptable to double-up on padstones?

[JackRusselll]

Our builder is removing the external wall between our kitchen and garage. Two bolted steels are going across the opening (spanning around 2.2m). This is the corner of the house, so there is a steel post specified on the outside corner wall and on the other side it requires a padstone.

The measurements of the padstone is specified as: 150 x 270 x 150.

The builder installed a padstone measuring 105 x 275 x 215. This was rejected by building control. Fair enough, spec wasn't followed (I don't know why). But now looking into it, maybe I do know why, it seems very hard to find a padstone of the specified dimensions, or even one bigger that can be cut down.

The builder suggested laying one padstone on top of another to get over the required dimensions. Do you think this would be acceptable? I can check with the structural engineer, but would like to get a gauge on if this is a stupid idea before I ask. Please see rough drawing below!

 

[tony1851]

How wide is the cavity; and would the steel beams sit vertically over the brick skins?
If the beams are only spanning 2.2m they wont be carrying much load so presumably you wouldnt need such large padstones.
It isn't necessary to bridge the cavity either - why not have 2 separate padstones, one on each skin.?

 

[JackRusselll]

How wide is the cavity; and would the steel beams sit vertically over the brick skins?
If the beams are only spanning 2.2m they wont be carrying much load so presumably you wouldnt need such large padstones.
It isn't necessary to bridge the cavity either - why not have 2 separate padstones, one on each skin.?

The cavity is about 90mm. The beams will sit on the padstone like this:

That sounds like a sensible option, I would need to check it with the structural engineer.

 

[noseall]

The cavity is about 90mm. The beams will sit on the padstone like this:

View attachment 379087
That sounds like a sensible option, I would need to check it with the structural engineer.

Your SE need to change his software sketch-up model. I've never seen U-beams with flange edges like that.

 

[noseall]

Our builder is removing the external wall between our kitchen and garage. Two bolted steels are going across the opening (spanning around 2.2m). This is the corner of the house, so there is a steel post specified on the outside corner wall and on the other side it requires a padstone.

The measurements of the padstone is specified as: 150 x 270 x 150.

The builder installed a padstone measuring 105 x 275 x 215. This was rejected by building control. Fair enough, spec wasn't followed (I don't know why). But now looking into it, maybe I do know why, it seems very hard to find a padstone of the specified dimensions, or even one bigger that can be cut down.

The builder suggested laying one padstone on top of another to get over the required dimensions. Do you think this would be acceptable? I can check with the structural engineer, but would like to get a gauge on if this is a stupid idea before I ask. Please see rough drawing below!

View attachment 379065

Looks ok to me and a stable load area.

 

[JackRusselll]

Your SE need to change his software sketch-up model. I've never seen U-beams with flange edges like that.

I hope he doesn't insist on the decorative flange! That might be my breaking point...

 

[tony1851]

Why do the majority of SEs bolt the beams together?
Its a waste of time and money and pointless.

 

[JackRusselll]

How wide is the cavity; and would the steel beams sit vertically over the brick skins?
If the beams are only spanning 2.2m they wont be carrying much load so presumably you wouldnt need such large padstones.
It isn't necessary to bridge the cavity either - why not have 2 separate padstones, one on each skin.?

Just to update, having consulted the engineer, this was deemed not suitable. It needs to span span both beams apparently .

Looks ok to me and a stable load area.

This was also deemed unsuitable as a solution.

This padstone is acceptable, meaning 10mm is lost in one of the dimensions. Bit frustrating as it's only 40mm more than the one that's currently in place...

 

[tony1851]

Has the se told you what the actual loading is on the beams, and why it is absolutely, unquestionably imperative that the padstone bridges the cavity?? He should at least explain to you why.
2.2m is a very short span and its hard to see how such a span could be loaded - in a domestic setting - to the point where separate padstones are not acceptable.
Can you upload a copy of the figures (with names and addresses cut out of course!)

 

[JackRusselll]

Has the se told you what the actual loading is on the beams, and why it is absolutely, unquestionably imperative that the padstone bridges the cavity?? He should at least explain to you why.
2.2m is a very short span and its hard to see how such a span could be loaded - in a domestic setting - to the point where separate padstones are not acceptable.
Can you upload a copy of the figures (with names and addresses cut out of course!)

On the notes it says 43.2kN total load

 

[tony1851]

Frankly, this is complete nonsense.
The load at each end of the beam is only 21.6 kN. If you've got normal brickwork, a 215 x 100 padstone on each skin would be more than adequate.
In fact, if you had a 150 bearing length, and the brickwork was ordinary commons, you wouldn't need a padstone at all because the bearing stress would be so low.
Ask your se for his calcs for the padstone size and why it is necessary to bridge the cavity.

 

[JackRusselll]

Frankly, this is complete nonsense.
The load at each end of the beam is only 21.6 kN. If you've got normal brickwork, a 215 x 100 padstone on each skin would be more than adequate.
In fact, if you had a 150 bearing length, and the brickwork was ordinary commons, you wouldn't need a padstone at all because the bearing stress would be so low.
Ask your se for his calcs for the padstone size and why it is necessary to bridge the cavity.

I don't deny anything that you've said, but at this point for an easy life we've just ordered the slightly larger padstone. Builder will be cutting out the existing teeny-tiny-40mm-short padstone, knocking a few more bricks out and replacing today.

This is just one element of a 'simple' build which keeps getting bogged down in bureaucracy and red tape.

 

[stevie888]

You can't blame the BCO for insisting on what's shown on the drawings, particularly engineers' drawings: that's his job, I'm sure you'd grizzle if something failed because the builder had undersized it and BC had not picked it up.

However in this instance I don't think you employed an SE just a chancer. The beams are way over sized by his own calcs and as Tony points out, the need for a padstone at all is marginal.

He's used Superbeam which always spits out the standard note for bolting beams together but his standard detail is probably 40 years out of date as it apears to show RSJs rather than UBs

FWIW in a double leaf situation like this the loadings will be different between the 2 beams so my approach is always to design the critical beam and then double up. Each beam is singly able to carry the applied load. If the loads beam to beam are markedly different then differential deflection may become an issue which is where the bolts may have some effect but it can only be very minor as you typically have only a section of 50mm tube as a spacer.

For big discrepancies it would be more usual to run some weld along the bottom flanges

 

[blup]

Is he a fully qualified SE?