load claculations for RSJ

Discussion in 'Engineers' Talk' started by sherb, Dec 12, 2006.

  1. sherb

    sherb New Member

    Can anyone tell me how to go about calculating the load on an RSJ beam so I can satisfy the building control guys. I have a 7x4 steel spanning a 2.2 opening. All that is sitting on it are floor joists, there is no wall above.
  2. mudhut

    mudhut New Member

    it really is very easy, sherb, but a little pricey. first, pick up a copy of the yellow pages. second, open checkbook wide. third, ring a firm of structural engineers....................

    on a serious note, calculating the loads, deflections etc yourself may be possible, but convincing bc will be another matter.
  3. grubber

    grubber New Member

    is there only 1 set of floor joists sitting on the beam. or is there going to be two seperate floors and joists sitting on the beam. what are the lenghts of the joists that are sitting on the beam. what is the rsj sitting on.i assume it is a single rsj sitting on 100mm wide wall. Brick or lightweight block?
  4. Part P Inspector

    Part P Inspector New Member

    Would it not be cost effective/safer just to install the heaviest duty RSJ for a given span and then your always covered, no?
  5. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    What do you want ? Three days we've been sleeping here, and you have to go and wake us all up!!!!!!!!!!!!!

    Only joking. ;)

    Two and a half days :)

    Mr. HandyAndy - really
  6. danbaile

    danbaile New Member

    I had a similar situation a few years ago. Being a Mechanical Engineer, I was familiar with all beam calculations. A book on dynamics will give you the necessary background. Watch out though. I used a reclaimed RSJ approx 10 x 5 by memory with no load above other than joists spanning 1.5m. The building inspector said that the beam was insufficient. I challenged him and asked to compare calculations consequently resulting a sameday pass. Have confidence in the figures and over egg your loads somewhat. I also proved that it would take a jumbo landing on my floor before the RSJ gave way!
  7. jimmythemap

    jimmythemap New Member

    Structural Engineer should cost about £200
  8. Charlie Far!ey

    Charlie Far!ey New Member

    Holy F*!

    You really dont know how to calc beams do you

    The 'engineer' states 'dynamics' - WTF is he on?

    Statics is for beam calcs - You need to know the loading of the beam is it a point loaded, UDL or two point?
    What its deflection max and the span.

    You need shear forces, Bending moments buckling moments .......... ofi - Get an s/e you have to have more money than brains for something this basic
  9. britishblue

    britishblue New Member

    Why reply now, to a question asked in December? Don't you lot read dates.

  10. daddyP

    daddyP New Member

    Well depends, im an engineer. if you can tell me the amount of floor from each side bearing onto beam i can send you some rough calcs or a program to use!!!
  11. daddyP

    daddyP New Member

    can you tell me the span of floor joists coming on from each side onto the rsj?? i can send you a rough calc.
  12. chippie244

    chippie244 Super Member

    This was posted in Dec and OP hasn't been back since. I doubt he's going to reply.
  13. nick harrison

    nick harrison New Member

    Hi I have a w truss roof wanting to put 2 no rsj to cut out the w section it's 4.1 m wide and I'm going to brace the roof back off the steel also the floor is 4.8 m between the two steels I'm told to use 8x3 timbers due to the span but what size rsj is needed please
  14. Jitender

    Jitender Screwfix Select

    You need to contact a structural engineer, is it for a loft conversion?
  15. nick harrison

    nick harrison New Member

    I'm not going through building regs as don't have room for a rigid staircase so wouldn't pass building regs
    I have contacted a se and they tell me I need architect drawings to work off
    But trying to keep cost down as only for storage not a habitual room
  16. Jitender

    Jitender Screwfix Select

    Other factors you need to consider such as a party wall agreement etc, if steels are to be placed on PW, could be a bit stressful if property is terraced etc with adjoining owners.

    Could look at telebeams but would cost about £6000. Need headroom of 2.1m from finished floor level.
  17. Jitender

    Jitender Screwfix Select

    There are narrow stairs available with an alternate treads.


    May be best to speak to an architect to see if other ways round it.
  18. sospan

    sospan Screwfix Select

    So you want to lift into an attic space at least 2 potentially 5m RSJ's for a space that is going to be used for storage !
    Johnst1a likes this.
  19. Mr Rusty

    Mr Rusty Screwfix Select

    With a trussed roof, the trusses don't just take the weight of the roof they also stop it spreading. In this case, I think you need proper input from a SE, otherwise you could run into problems in the future even if nothing actually happens. Any modification to a trussed roof is going to need some calcs and certs.
  20. Doall

    Doall Active Member

    I've just knocked through a side off a house into the garage and used concrete lintels. Opening was 1400mm and I used 1800mm lintels. B/c was happy with that

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice