Fitting an RSJ into a shared wall...

[stevecol]

Just a swift one really before we call the BCO out ot look at our house: we live in a fairly standard '30s semi-detached with two reception rooms and are looking to knock the supporting wall down between them to create one room. We'd therefore install an RSJ etc.

My question is: the wall between us and our neighbours is two standard bricks thick (ie. around 180mm + mortar) and I assume we're allowed to embed the RSJ halfway (ie. 90mm), in case they want to do the same one day on their side. Is this enough, because it doesn't seem an awful lot to rest a steel beam on that's going to support the wall above? Also, would this use a spreader installed in the wall to spread the load? I've heard that a pillar can be built with padstones, but we really want to avoid this as this would encroach into the hall space. The span is around 3.5 to 4 metres. Any light anyone could shed would be massively appreciated.

Cheers!

 

[^woody^]

The wall will be 230mm (if solid) or 270mm (if cavity) plus plaster, and the beam will have 110mm to sit on, and it will normally sit on a concrete padstone or similar.

Also do a search, as there are quite a few posts on here with this query and the implication of knocking the plaster, paintings and plates off the neighbours wall when you start knocking. Also search on party wall act

 

[Bowness72]

Obviously I dont know what the beam is supporting but the fact that it only has 90mm bearing isnt such a big deal (depending on the quality of the masonry and workmanship when it was laid etc.)
Normally you would install a concrete padstone below the end of the beam (eg. precast concrete lintel cut to length), the length and depth of which would depend on the amount of weight being carried by the beam. Also a standard brick wall of that age I would expect to be approx. 230mm wide so not sure what the exact construction is you describe.

You may also want to refer to the party wall act regarding installing the beam half way into the wall, which basically will mean you notifying your neighbours (in writing + plans etc.) what you are doing, and take it from there. Others on here will probably be able to advise better regarding details of the party wall act but guidance is available on line also.

 

[stevecol]

Excellent, thanks both.