RSJ end bearing and padstones

[azreal]

I have been been running into so much trouble regarding taking down a wall and replacing with an RSJ.

The plans show my RSJ 254 x 102 x 28 UB grade s275 length 2.9m

or 152 x 152 x 30 UB grade s275

Both have been approved. the first was far to tall for us and would hang down a mile, so we got the shorter one drawn up.

Problem is he has specified 150mm thick padstones.
The UB was going to rest on the inner skin of the wall. however that only 100mm. We dont really want a part of the wall 50mm still remaining.

Do you think I could get away with 100mm padstone at one side? Or have it resting on the outer skin too, and put back 1/2 bricks to seal it in?

FYI the Mmax he calculated was 34.6 kNm

Cheers for the advice.

 

[noseall]

You must have read it wrong.

A structural engineer would not specify a padstone 150mm thick that sits upon 100mm of masonry as there is no point to the extra 50mm.

Are you sure it was not 150mm deep i.e. a 2 course pad-stone?

 

[azreal]

You must have read it wrong.

A structural engineer would not specify a padstone 150mm thick that sits upon 100mm of masonry as there is no point to the extra 50mm.

Are you sure it was not 150mm deep i.e. a 2 course pad-stone?

He has specified 150mm deep padstones for one calculation and for the other 150 thick.

What does that mean

 

[noseall]

He has specified 150mm deep padstones for one calculation and for the other 150 thick.

What does that mean

It means you have read it wrong. Probably.

 

[azreal]

He has specified 150mm deep padstones for one calculation and for the other 150 thick.

What does that mean

It means you have read it wrong. Probably.

OK but my plans state end bearing 150mm.

Thats fairly clear.

Could the architect have made a mistake?

 

[noseall]

Maybe your plans are reiterating a generic measurement, or that your designer has assumed an in-line end bearing.
What ever the outcome, a 100mm thick wall can only support a 100mm wide pad-stone.

Phone your SE.

 

[mnemonix]

OK but my plans state end bearing 150mm.

An 'end bearing of 150' means the lintel must project 150mm either side of the opening and sit on padstones over this length. It's a standard detail.

Neither the lintel nor the padstones should be wider than the wall however, that makes no sense.

 

[azreal]

OK but my plans state end bearing 150mm.

An 'end bearing of 150' means the lintel must project 150mm either side of the opening and sit on padstones over this length. It's a standard detail.

Neither the lintel nor the padstones should be wider than the wall however, that makes no sense.

so if the wall is 100mm then end bearing of 150mm is wrong?

 

[^woody^]

If he has calculated the beam based on 150 bearings, then you need to get him to confirm the beam size again and the padstones

But, just use a 440x100x215 padstone and be done with it .... one that is the same size as a block. Building control wont normally argue with that

 

[mnemonix]

so if the wall is 100mm then end bearing of 150mm is wrong?

NO! the end bearing has nothing to do with the thickness of the wall. it's the distance the lintel extends beyond the opening and bears on the padstone!

http://www.atspeed.co.uk/cavity_wall_install.html

 

[azreal]

so if the wall is 100mm then end bearing of 150mm is wrong?

NO! the end bearing has nothing to do with the thickness of the wall. it's the distance the lintel extends beyond the opening and bears on the padstone!

http://www.atspeed.co.uk/cavity_wall_install.html

OK but how can you go 150mm past the opening when the wall is 200mm thick.
you would have to go into the outer skin which I have been told is a nono.

Am i wrong or am I missing something.

 

[^woody^]

so if the wall is 100mm then end bearing of 150mm is wrong?

NO! the end bearing has nothing to do with the thickness of the wall. it's the distance the lintel extends beyond the opening and bears on the padstone!

http://www.atspeed.co.uk/cavity_wall_install.html

Of course it is correct

If OP's inner skin is only 100mm wide, then how can he have a 150mm bearing. So it has everything to do with it

However the OP's wall seems to be a solid wall so there is scope for a 150mm bearing . That is why he needs to confirm with the designer if a 150mm bearing has been designed/is required

 

[mnemonix]

Ok, you're not missing anything, I didn't appreciate you only had the wall thickness to bear on As others have said consult your architect or SE to check, but 150 bearing is usually just cited as a standard detail unless it's been specifically designed differently.

 

[azreal]

it is a solid wall not a cavity call.

I have asked the designer still waiting to hear back.

I have read in some places a 100mm end bearing could be ok.

Lets hope so.

 

[Static]

100mm end bearing should be fine.. your SE just needs to adjust calcs to a reduced bearing and will probably increase the length/depth of padstone to compensate..