RSJ span

[kevin_robson]

I am removing some french doors and blocking up with a stud wall - see another post for details.
The doors are not original and an RSJ has been put in to support the wall above.

When I removed the plaster last night the RSJ only overlaps the bricks at the edge of the doors by approx 5 inches. The distance between the outer walls and the french doors is probably 18 inches, so I was expecting the RSJ to reach almost to the walls. As it is the upper wall above the RSJ is being supported by the RSJ which is only really being supported by one brick at either side.

Is this OK, or should a longer RSJ have been used? Note that this was probably done years ago, so doesn't need to adhere to building regs as such, just be safe.

 

[Richard C]

Current regs state 150mm (6”) but as you rightly state, if it was done some years ago you do not have to change them retrospectively. The reason why the min overhang was introduced is to prevent diagonal sheerline cracks appearing outwards & upwards from the corners of the lintel; windows also now have to be a certain distance from the corners! Yours is not that far adrift & if it’s been up there a while & there is no evidence of cracking I’d leave well alone.

I have cast-in-situ concrete lintels in the 60’s property I’m renovating, some with only a 4” overlap; & many have sheerline cracks on the internal blockwork but the evidence is that it’s not recent movement. Having had to remove 2 of these bu**ers for some other work, I can confirm they are well stuck in there & weigh a bl** y ton so I’m certainly not ripping them all out; I’m raking back to block, making repairs & re-rendering/plastering using steel reinforcing mesh.

 

[kevin_robson]

Thanks a lot. That has put my mind at rest. As you say, there are no visible cracks or anything, I just expected (in my inexpereinced view) that a bit more of an overlap would have been required for this sort of thing.

I've enough work as it is without making any more for myself, so I'll leave it well alone.