Bolting a steel beam to another steel beam.

[vincentianpinner]

The first beam has been in a while it's got a plate welded with the holes for the bolts. Then needs another one attached to form a T shape. The first one is nice and plumb and I assume the second one will be square and true but it occurred to me that once it's screwed tight it might be off slightly and not giving a perfect 90 degrees.
My question is, is there any way of adjusting it slightly if that's the case? Possible where the washers go?

 

[stevie888]

Always best to fit all steels at the same time if you can to avoid this worry.

You may need to add some shims between the plates if you have a misalignment. Unless you have a really bad fabricator and or installer of first beam you'll only need very thin sheet: maybe cut up a baked bean tin.

 

[noseall]

The first beam has been in a while it's got a plate welded with the holes for the bolts. Then needs another one attached to form a T shape. The first one is nice and plumb and I assume the second one will be square and true but it occurred to me that once it's screwed tight it might be off slightly and not giving a perfect 90 degrees.
My question is, is there any way of adjusting it slightly if that's the case? Possible where the washers go?

Is the new beam dictating where the wall goes or is it being aligned under an existing wall?

 

[vincentianpinner]

Is the new beam dictating where the wall goes or is it being aligned under an existing wall?

Under existing unfortunately.

 

[vincentianpinner]

Always best to fit all steels at the same time if you can to avoid this worry.

You may need to add some shims between the plates if you have a misalignment. Unless you have a really bad fabricator and or installer of first beam you'll only need very thin sheet: maybe cut up a baked bean tin.

Something that can crush you mean?

 

[stevie888]

Something that can crush you mean?

No I mean something thin but solid so you can pull the bolts up tight. Your bolts are likely 100mm or so apart laterally so if you pack 1 side by 1mm you will see 30mm movement 3m along the beam

 

[noseall]

Under existing unfortunately.

Put your beam in under the wall. Bolt it up but don't tighten the nuts too much. Mortar it all up and remove the props. Tighten the bolts (with any necessary shims) once the wall above has 'settled'.

 

[stevie888]

Put your beam in under the wall. Bolt it up but don't tighten the nuts too much. Mortar it all up and remove the props. Tighten the bolts (with any necessary shims) once the wall above has 'settled'.

Sorry but that is a bad idea: you want the support as rigid as possible before letting the load ac fully: any movement can lead to cracking.

 

[noseall]

Sorry but that is a bad idea: you want the support as rigid as possible before letting the load ac fully: any movement can lead to cracking.

I'm talking about applying a modest pressure to the nuts without spraining the beam and then fully tighten them afterwards. What do you think might happen, lol?

 

[Dereekoo]

Put your beam in under the wall. Bolt it up but don't tighten the nuts too much. Mortar it all up and remove the props. Tighten the bolts (with any necessary shims) once the wall above has 'settled'.

Will not the settling lead to cracking of the supported wall ?

 

[noseall]

Will not the settling lead to cracking of the supported wall ?

Probably used the wrong term there. Loaded or load transfer was probably the right word or some such, i.e. when the beam takes up the weight from above.
We did something similar as we were faced with a similar scenario to the OP...

shazzabeam10.jpg

• noseall
• 31 Mar 2025

shazbeam1.jpg

• noseall
• 31 Mar 2025