Packing between steel beam and brickwork

[padstar]

I have my steel beams being installed this week and just wanted to check what the procedure is for packing between the steel and brickwork above.

Others will be doing the work I just want to know how it should be done to ensure it is done correctly.

Asuming a 10-20mm gap between top of steel and underside of brickwork. Is a dry ish strong sand cement mixture just packed into the gap and left a few days before removing the props?

 

[oldbutnotdead]

You get the steel level and as close to the bricks as possible. You pack any gaps usually with slate then point up with a bit of mortar.

 

[wessex101]

I have my steel beams being installed this week and just wanted to check what the procedure is for packing between the steel and brickwork above.

Others will be doing the work I just want to know how it should be done to ensure it is done correctly.

Asuming a 10-20mm gap between top of steel and underside of brickwork. Is a dry ish strong sand cement mixture just packed into the gap and left a few days before removing the props?

Generally this is correct. I tend to follow the BRE guidance which states leave a gap between the top of the beam and the brickwork, pack it with slate or shims and make sure the gap is well filled using well compacted dry packing. This is just a dry mortar mix rammed in to the gap to make sure the gap is totally filled and the mortar well compressed, it doesn't need to be especially strong just dry so you don't get the usual shrinkage with wet mortar.

If the gap is too small it is almost impossible to get any kind of tool in the gap to ram the mortar to compress it. That is why you often get those initial settlement cracks when a new beam is installed, inadequate dry pack.

 

[^woody^]

Mortar on the beam, push the beam up, no need to mess about packing

 

[conny]

Mortar on the beam, push the beam up, no need to mess about packing

This sounds like are suggesting the mortar will act as a glue between the beam and the brickwork above. This is not so. If you jack the beam up to the brickwork you will still need to fit packers under the beam on top of the support pedestals.

 

[^woody^]

This sounds like are suggesting the mortar will act as a glue between the beam and the brickwork above. This is not so. If you jack the beam up to the brickwork you will still need to fit packers under the beam on top of the support pedestals.

No im suggesting that the mortar acts like every other mortar joint in every wall.

And if the bricklayer knows what he's going, he will then install the bearings likewise.

 

[wessex101]

No im suggesting that the mortar acts like every other mortar joint in every wall.

But it doesn't. If you are building the wall from scratch it is loaded gradually and and the entire wall will go through the same shrinkage.

With the insertion of a beam the bed joint and bearings take the full load the second the props are removed with potentially some of those loads being concentrated over a small area, especially at the bearings. In addition only the bed joint above the beam and the bearings will have any shrinkage which could potentially lead to some minor movement.

I appreciate that buttering the top of the beam and jacking it into place is quite common but I have not seen that method supported by any official technical guidance. It also depends on your attitude to shrinkage cracks and possible minor settlement cracks.

 

[^woody^]

But it doesn't

But it does.

And obv's you don't remove the props until the mortar has gone off

And where is this official technical guidance that you speak of? Does any exist? Who publishes the guidance to knocking out a wall and putting in a beam?

And shrinkage occurs (if it is even going to occur if you use the right mix) along the bed length, not the 10mm height.

And settlement cracks in a single joint? Please.

 

[wessex101]

And where is this official technical guidance that you speak of? Does any exist? Who publishes the guidance to knocking out a wall and putting in a beam?

As I said in my original comment, BRE (GBG 20). Please feel free to share the guidance advocating your method?

 

[^woody^]

Lol. The GBG or nothing. . Like following the instructions on a bottle of Fairy liquid or you're not washing up properly.

The method I use - I don't claim it as mine as it predates me and that guide, is above .... as are all the beams fitted using it still above, and not below.

 

[padstar]

So I have the back wall opened up and the nearest course above the steel looks like it will leave a 50-60mm gap from top of beam to underside of brickwork. I assume this needs more than just dry pack.

What is the method here? Cut 30mm slips and bed them in on the steel then dry pack above?

 

[^woody^]

30mm slips and 30mm packing?

Brick on edge, or push the steel up.

 

[padstar]

sorry woody i am confused.

The steel is going to be limited as to how far up it can be pushed as it links to other steels on either side. If it can be pushed up then i will.

If not how does it work as a brick on side is likely to be too big. Sorry if i am being thick but want to get it all filled in as soon as the steel goes in.

If it was 50mm can i cut 30mm concrete slabs to the correct width and brick them in?

 

[cdbe]

I cut up some 50mm concrete slabs when faced with a similar situation. They are flat so can sit on the steel without a bed.

 

[^woody^]

sorry woody i am confused.

If not how does it work as a brick on side is likely to be too big. Sorry if i am being thick but want to get it all filled in as soon as the steel goes in.

You take one course off, and put a brick on edge back in