Padstones

[pritch]

Hi

I'm not really sure what kind of pad stone I need for this rsj that is roughly 7m long and weighs around 650kg. 

The brickie said it's a standard concrete block size padstone I need? 

Thanks 

 

Edited May 19, 2019 by pritch

[Oz07]

I might be missing it but can't see padstone size specced on there. Usually it is detailed. Ask SE

[nod]

As above 

 

I simply used 100 x 150 concrete lintels As I had a lot of them and the cost can soon rack up 

BC was absolutely fine with me cutting lintels into 400 lengths 

[PeterW]

SE would need to spec this as there is too much missing info. For example, what’s the bearing material (dense block, lightweight block, brick..?) and what is the available end bearing ..?

 

Given that is quite a chunky steel, you’ll be looking at Naylor 440x215x100 pad stones as a minimum I would expect. 

 

Have they specified any restraint method such as bolting ..??

[Temp]

+1 

 

You need to know the load on the beam (in Newton's) and the load bearing capability of the blocks in the wall (Newton's per square mm).

 

Divide one by the other and you get the minimum area of the pad stones (in square mm).

 

At least that's the theory. In practice it's more complicated. Calculating the load for example isn't simple. It's not just the weight of the beam! It's everything above it and some. Wind and possibly snow loading as well. There are also safety factors to be included. It's a job for your structural engineer.

 

We have some narrow pillars between windows and our  SE recommend denser blocks in those area because there was a limit on how big the padstone could be.

 

[pritch]

Hi

I've just got back and looked at the email from the engineer.

He said to lay it on a standard block size padstones on the single block course with the front plate resting on the face brick.  

I'm surprised to see the over hang of the steel is just 150mm each end.  It doesn't seem a lot for  a 7m rsj. 

Is this normal? 

Thanks 

Ps. That block with the cross on it above the steel.  Would this be a cut down block or a timber wall plate? 

Edited May 25, 2019 by pritch

[Brickie]

43 minutes ago, pritch said:

Would this be a cut down block or a timber wall plate? 

That’s a wall plate. 

[pritch]

Ok thanks 

Would this be fixed some how or just bedded on ? 

 

[PeterW]

30 minutes ago, pritch said:

Ok thanks 

Would this be fixed some how or just bedded on ? 

 

 

Tek screws to hold that onto the RHS. Is that a flat roof above the steel..??

[pritch]

On 25/05/2019 at 22:25, PeterW said:

 

Tek screws to hold that onto the RHS. Is that a flat roof above the steel..??

Yes it's a flat roof. 

[PeterW]

Just now, pritch said:

Yes it's a flat roof. 

 

Ok makes sense ..! Was wondering how you’ve managed to get a 7m span with such a small steel ..!!

[pritch]

I'm still wondering if the 150mm minimum bearing should be increased ??

It doesn't seem alot for a 7m metre beam.  

[PeterW]

You can make it as long as you want however you’ll have an issue with the flange showing through the front brick course if you’re not careful.  It may also alter your padstone sizing. 

[pritch]

Just took delivery of the padstones. 

They have a raised edge ..... not sure if I should grind this off? 

Does the rsj really sit on a bed of compo ? 

This is what the builder said, though I can't really see it doing alot with 700kg on top.  

[PeterW]

19 minutes ago, pritch said:

Just took delivery of the padstones. 

They have a raised edge ..... not sure if I should grind this off? 

Does the rsj really sit on a bed of compo ? 

 

 

 

Don’t need to grind that off 

 

and yes, compo and slate to pack it level

[Oz07]

Will be more of a smearing of compo than a full bed. If it helps you to think of it like that. 

[bassanclan]

19 hours ago, PeterW said:

 

Don’t need to grind that off 

 

and yes, compo and slate to pack it level

You're not supposed to use slate packers now. If you have some scraps of plate steel use them instead.