Deflection Head under Steel Beam

[MortarThePoint]

I have a 3.6m opening under a steel beam which is to have metal frame (M.F.) added to make two door openings (each French doors). I am supposed to have a deflection head to avoid the M.F. accidentally becoming load bearing and so buckling. The M.F. is to be flush with one surface of the dressed beam and have a small reveal on the other side. On the side that is flush, I am struggling to work out how to have something that will plaster well. I expect the deflection head shouldn't be subject to movement, but is there just in case. Does anyone have any good thoughts as to what I can do?

 

 

The beam is dressing in fire proof plasterboard which stands a bit forward of the blockwork, but HardWall can plumb that up. I have included plenty of battens on the underside of the beam during the beam dressing to allow the MF to be attached to the beam. The image above shows a gap above the MF whereas in reality it is normally achieved by using deep track and a c-stud cut short within it.

[nod]

It’s so small that I wouldn’t worry 

Fix a strip of PB to the track and fix through it It will never become load baring whilst it’s sat on the bw 

[saveasteading]

If the beam is simply supporting a wall and perhaps a floor onto the wall, then most of the load is already on it and it has already deflected. Only a bit more might result from people jumping on the floor, severe wind, snow if its a flat roof.

The deflection head is still sensible but i woudn't fret over a few mm reduction if it helps, then fill with mastic or painters mait.

[MortarThePoint]

34 minutes ago, nod said:

It’s so small that I wouldn’t worry 

Fix a strip of PB to the track and fix through it It will never become load baring whilst it’s sat on the bw 

 

Hi nod, the gap is all the way along the length of the beam. are you saying to run the plasterboard up to the beam?

[MortarThePoint]

20 minutes ago, saveasteading said:

If the beam is simply supporting a wall and perhaps a floor onto the wall, then most of the load is already on it and it has already deflected. Only a bit more might result from people jumping on the floor, severe wind, snow if its a flat roof.

The deflection head is still sensible but i woudn't fret over a few mm reduction if it helps, then fill with mastic or painters mait.

 

I did ponder that but became slightly concerned about thermal movement

[saveasteading]

1 hour ago, MortarThePoint said:

slightly concerned about thermal movement

You're right  and a bit of cracking is likely whatever you do. 

If you build this with the 10mm gap I'm sure a solution will present itself as it's a tiny gap to bridge with an oversailing board or trim.

[MortarThePoint]

Just now, saveasteading said:

You're right  and a bit of cracking is likely whatever you do. 

If you build this with the 10mm gap I'm sure a solution will present itself as it's a tiny gap to bridge with an oversailing board or trim.

 

I've already boarded the beam so the board over the MF on the flush side needs to come up to the board already on the beam. That means I either close the 10mm gap with the board or leave a gap that skim won't be able to bridge surely?

[saveasteading]

If you board to 10mm short and fit an L shape or quadrant over the gap but fixed above, it will form a sliding joint.

[nod]

3 hours ago, MortarThePoint said:

 

Hi nod, the gap is all the way along the length of the beam. are you saying to run the plasterboard up to the beam?

Yes 

normally screw it to the flat of the track Then shot fire it to the beam 

That way it prevents the track being fixed directly to the beam