Understanding Beam Calcs / Padstone Support


26 Apr 2013
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United Kingdom

Hoping someone can help decipher these calcs for me.
This is purely for the 'Beam Design' portions. Not the 'Chimney' stuff.

My query relates to the supporting the beam on the existing walls. Ive included the entire thing incase. But the chimney has been done.

I understand the padstones are to be 300x100.
Via email engineer said the following

  • Beam to support wall to be 203x102x23.UB OR 152x152x23.UC (+300x100 padstones)
  • 450 pier to remain at external wall bearing
Hes made no mention of the internal wall supporting the other end though. So im taking that to mean it will sit on the current wall, which is solid brick, running 90 degrees opposite way. There is no pier to leave, as the wall is flat, doesnt have a 'T' section where the beam will go.

So the padstone would sit entirely on the brickwork, 300mm across, 100mm deep. This would mean making good / replastering the other side of the wall once finished. As its only a single brick, so will go through this other side.

The pier end, should it sit entirely on the pier, or should it be pocketed into external brick work?

Its solid brick wall, no cavity. I understand the beam will be a thermal bridge if its in the external wall? But not sure it can sit on just the pier, even though thats tied into external wall. I think the padstone needs to be 300mm wide 100mm deep? Rather than fitted 100mm wide 300mm deep if that makes sense?

Ive tried to contact him, but no joy so far. These were done a few years ago, which is why the chimney is already done.

House is 1930s solid brick external walls. Brick internals, upper floor walls are literally built on top of the floorboards (original). Suspended timber floor downstairs, internal walls down to concrete.


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Padstone would be 300mm long, 100mm wide and 100mm deep (/high).

From your description this is what I think it should look like in elevation:
  • Thanks
Reactions: Rom
Thanks for the reply. Your picture is pretty much what I have.

Only issue the 'return' isnt 300 wide. Its a single brick. Excuse the awful drawing, im on my phone.

Black is current walls, red is beam, yellow is padstones.
I cant fit the one on the pier width ways as a single brick. But im not sure it can fit how ive drawn it either!
Ive not taken '450 pier' to mean build one? There is a window on one side, so would lose that, which wasn't part of the plan.

Also only finding padstones in 300x140x100.

Last edited:

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