RSJ or Reinforced concrete? What sizes?

[thesapper72]

Am in the process of pricing up knocking a ground floor wall down in my house. The wall is part of the original external cavity wall, width 250mm.

The new opening will span 3.5m. Would reinforced concrete lintels be sufficient for this or would you advise an RSJ. Roughly what sizes would they need to be?

I will be getting calculations done for this, but just want to know rough sizes required so that I can start to see how much things will cost.

 

[noseall]

P.C.C. lintels' suitability are limited to certain applications and locations and are rarely chosen for large load-bearing spans.

It is likely that you will need a pair of steels bolted together along with the relevant calculations in order to satisfy building control.

 

[themiddleagedun]

Two steel beams. Concrete ones, at a sufficient depth would be very heavy
As for size 200x100ish.

 

[Architexeter]

It would be a steel I should think.

I'm assuming it is holding up the wall above, first floor and also the roof.

Let us know some more info and someone should be able to give you a better idea of size but as a guestimate I should think it would be a pair of approx 200mm high x 100 wide steels.

Hope that helps.

 

[thesapper72]

Thanks for the quick replies.

Had been thinking it would have to be steel. Yes it will be supporting the wall above and the roof.

The upstairs floor joists are currently built into the exiting external wall so these will be adding to the load across the new opening.

 

[Static]

Concrete would be inappropriate.. as said above a couple of steel beams in the region of 200mm deep..

Course that will get firmed up when you get the calcs & drawings for Building Regs done.