External wall RSJ - Amount of brickwork required

[cam1989]

Morning all.

Just a quick one; we've had a couple of quotes for the installation of 2No. RSJ's to an external wall. This particular corner of the house is almost an L shape, with the RSJ's being inserted in the vertical part of the L. Presuming the length of this vertical part is 2300mm, how much brickwork will need to remain for the RSJ's to sit on?

Hope this makes sense. If not I can post an CAD drawing to make things more clear.

Edit to clarify: it'll be one opening, but two steels will be required as it's a cavity wall.

 

[tony1851]

how much brickwork will need to remain for the RSJ's to sit on?

That should be on your engineer's calculation sheet.

 

[cam1989]

how much brickwork will need to remain for the RSJ's to sit on?

That should be on your engineer's calculation sheet.

I don't have that, as theyre only quotes. As it is I'm trying to do a 2D layout of what the room (kitchen/diner) will look like once it's done, to make best use of the space.

 

[tony1851]

Why not post a sketch plan? Whether or not you need a pier depends on floor spans etc.

 

[cam1989]

Why not post a sketch plan? Whether or not you need a pier depends on floor spans etc.

If you need any more detail let me know. Not afraid to admit that structural engineering is outside of my comfort zone.

The 9" wall is the exterior wall of the house. Ground floor joists run top-bottom; first floor run left-right.

 

[cam1989]

Anyone?

I've been looking at Part A which suggests a minimum return of 665mm. Granted I'm reading it on a 4" screen and I've probably missed something, is this the amount of brickwork I'd be looking at?

 

[tony1851]

The 665 dimension is a rule-of-thumb measurement, which will be accepted by the BCO.

You can go smaller than this, but the BCO is then at liberty to ask for structural calculations to prove compliance with Part A.

This is not just to do with the strength of the wall, but also involves lateral stability of the extension or house as a whole.

If stability is raised as an issue, it is necessary to consider a plan of the whole house, not just a small part of it.

 

[themiddleagedun]

Tony, It only looks a small extension, if the room had originally been built to the proposed new size. Presumably there wouldn't be any returns then, so why the need for any now?.. Just curious

 

[cam1989]

Tony, It only looks a small extension, if the room had originally been built to the proposed new size. Presumably there wouldn't be any returns then, so why the need for any now?.. Just curious

Above the proposed rsj is the external brickwork for the first floor of the house.

I've decided to get a structural engineer on board. None of the builders we've had quotes from have mentioned it, however I'm keen to avoid any problems when it comes to selling.

Thanks for the advice!