RSJ for 75mm Cavity Wall

[AndrewPerry]

I'm building an extension at the moment and need a RSJ that will suppor

a 278mm (75mm cavity) wall above my garage. Is it possible to get the this size, or would it be better to have two, one supporting each wall If the latter, what goes in the gap between the two? For info, th span in 2.7m.

Thanks

-- AndrewPerry

[Set Square]

I would have thought that 2 would be better - one for each skin. A single one would be a bit heavy! Is it over the garage door? If so, stick some plasterboard on the underside with gripfill (after fitting the door frame) to close the gap.

Having said that, can't you get a Catnic lintel which would do the job?

[dg]

The first question is what does the spec say - this is controlled work so what has been calculated and approved?

Without knowing the loadings, it is impossible to say what sized section is required.

Generally you will use two steels, which are bolted together, but kept apart with steel tube to form the cavity.

Don't forget the padstones.

dg

[kdband]

Sounds to me like a heavy-duty lintel is what you want, e.g. :-

't forget you will need to allow for the end-bearing (probably minimum 150mm at each end). If you're not sure what you need then maybe you should check with a structural engineer or run your thoughts past the building inspector at the very least.