RSJ into single skin wall

[Stiart]

Hi, couldnt find the answer to this anywhere...please dont answer 'structural engineer' since i can work that one out myself but before i get to (do that i want to know if its even feasible for my planning and hope someone can help since ive been scoring the internet for an hour and i find nothing so perhaps it not possible!

Semi detached house, 1930s heavy duty engineering brick outer and inner ground floor walls. Some form of heavy 120mm breeeze block-like wall in interior walls. Rear of house shown below has two rooms (not shown) separated by a 120mm interior 'wall' of around 1.6m and a space of 0.8m on the left thus totally the 2.4m. Joist run side to side (ie up down in diagram) . The wall thus kind-of supports right hand side joist and above it is a block wall on the first story. That wall is not a contiuaiton of the lower one since it sits on floor boards, which sits on the joists which sit on the 1.6m wall. Due to whats in rest of house were joists go full width unclear if wall is really supporting but due to block wall above it it might be (probably not even possible now). Anyway i want to knock down that wall and put an RSJ where it says 2.4 Span. Assume in all this the walls are strong

The problem...at both ends of the wall the RSJ would only go perpendicular into either the left or right walls which are only 120mm wide where as you are supposed to need 150mm. Regardless of that its only 30mm difference i want to know if this is possible and anything i could do to mitigate this - eg stick concrete llintels of length X under them perpendicular to beam, some plates welded on underside of beam perpendicular to it, make a nib at top of wall like churches do for supporting arches. NB an option is not to provide extra steel supports at either end. I worked out the RSJ i need is 127*76 - 13 if that helps

Any help appreciated and i hope answers would help others

 

[tony1851]

That would not be a problem, as long as you have a decent-length spreader set on each wall, at right-angles to the beam.
The precise length of the spreader would depend on the load the beam was carrying, and the compressive strength of the masonry.
But assuming the wall was something of the strength of lightweight concrete block, as an off-the-top-of-the-head guess, I should think something like a 300 long x 100 wide by 140 high concrete spreader would be fine.

 

[frutbunn]

As above, but speak to your BCO most, but not all, will accept this on a concrete pad and confirm an acceptable size without a SE. Easiest way is to cut a couple of pieces off a concrete lintol. or use a steel spreader plate, unfortunately my uncle retired and sold his business so I no longer have access to free steel offcuts!!