Steel beam calculations

Discussion in 'Engineers' Talk' started by chodaboy1979, Jan 18, 2021.

  1. chodaboy1979

    chodaboy1979 Member

    Hi there. Can anyone advise what a fairly simple steel beam calculation should cost? Looking to remove chimney breast and supporting wall between dining room and kitchen. The chimney breast above has already been removed but the wall is supporting joists and wall on first floor. Posted the job on mybuilder and received 2 quotes, both of which over 500 quid! Now call me tight but I think that's a bit excessive so had a look at going with one of the online firms, who charge a much more pocket friendly £50. But the maximum span they will do is 4m. I need just shy of 5m.
    I know decent professionals don't come cheap, I used to be a joiner by trade, but surely 500 notes for maybe a couple of hours work is taking the p*** a bit? Or am I wrong?
     
  2. chodaboy1979

    chodaboy1979 Member

    I should clarify, the job I posted on mybuilder was purely for the calculations from an SE
     
  3. Jord86

    Jord86 Screwfix Select

    Try some more SE's, if they're all around £500 then that's the going rate, though personally I would have expected around £3-400.
     
  4. chodaboy1979

    chodaboy1979 Member

    Thank you, that is still more than I expected but if that's the going rate I guess that's what I will have to pay. What are your thoughts on the the online calculations? How are they able to do them so cheaply?
     
  5. rogerk101

    rogerk101 Screwfix Select

    Because it's a case of looking it up in a table ... they're not calculating anything.
    Even you can look the same stuff up in the same tables, and it would cost you nothing other than your time.
    My SE designed an entire double pitched roof for me for £500 so whoever you contacted is just taking the pi88.
     
  6. stevie22

    stevie22 Screwfix Select

    Designing a beam is so simple a monkey could do it because we use software to do the job. Some stuff comes from tables: joists, rafters etc but usually beams are designed individually.

    The difficulty is in deciding the loads we are going to design for: this entails looking at the whole structure of the house and tracing load paths. On line calcs are going to be based on your input: wrong input, wrong output, your problem.

    £500 does seem a bit strong but if he is coming out to measure up, do a drawing to submit to BC with the calcs, submit the application all covered by PI maybe not as bad as you think.
     
  7. Rob_bv

    Rob_bv Active Member

    I've paid anywhere from £100 to £600 for calcs, depending on the complexity of the job; bear in mind, you're not just paying for their time, you're also paying the costs for their indemnity insurance. The cheap £50 online ones, you're unlikely to be covered in case of their errors.

    My most recent charge was £300 for beam design for knocking through a load-bearing wall in a ground floor flat, complete with site visit to measure up, drawings and full spec.
     
  8. JasonCSmith

    JasonCSmith Member


    As above. Any decent SE will be able to assess loads and make judgements from experience, including the need for any lateral resistance in beams such as ridge beams. You get what you pay for. Lots of annoymous online engineers around just banging out simple calcs without due regard for risks or accuracy. I bet they just up the steel size to give extra protection.
     
  9. chodaboy1979

    chodaboy1979 Member

    Thanks for the replies chaps. All I asked for was the calcs, no more involved than that so I do think perhaps a bit pricey. I'll try contacting some other firms, see if I can get the price down a bit.
     
  10. Severntrent

    Severntrent Screwfix Select

    Give me the loads on the beam and I'll work something out, I'm a civil engineer with a smattering of structural design knowledge, I don't have any PI but it will be mates rates or whatever you think is appropriate, I've got so much time on my hands I need things to do ;-)
     
    Jord86 and rogerk101 like this.
  11. chodaboy1979

    chodaboy1979 Member

    Mate, that's jolly nice of you. Unfortunately I didn't see your reply until this morning and I'd been in contact with an SE yesterday and agreed for them to go ahead. I will keep you in mind though if that doesn't work out for some reason. Would your calculations satisfy building control?
     
  12. Severntrent

    Severntrent Screwfix Select

    Don't see why not, perhaps Frutbun can comment
     
  13. rogerk101

    rogerk101 Screwfix Select

    Building Control is far more concerned to see that the factors that went into the 'calculations' were realistic than who entered them. I've done my own calcs before when I chose to use oak beams rather than steels and BC was fine with the calcs that I showed them. (I'm a mere electrical engineer, but BC didn't know that.)
     
  14. Severntrent

    Severntrent Screwfix Select

    Ok just to keep the grey cells ticking over I'll do some calcs. I'll base my calcs on a clear span of 5m, I'll assume that the wall that is being taken out supports the floor joists of the floor/ceiling above and the bedrooms either side of the wall are 4m wide, I'll assume the wall dividing the bed rooms is a 1/2 brick thick wall 2.4m high and this wall supports the ceiling rafters of the 2nr 4m wide bedrooms and there is no further loading from the roof structure above i.e. support struts. OP can you confirm/spec the foregoing and come judgement day we can compare my results with your SEs.
     
  15. Frutbunn

    Frutbunn Active Member

    Should be OK, if there are any doubts with the calcs we would get them checked either with our in house engineer (larger authority) or external consultants (smaller authority). I used to use the in house engineer who used to do them as guvvy jobs for my guvvy jobs as did a couple of the other lads, there used to be a lot of passing around of plain envelopes under the nose of my old boss!!! Last one was about £130 but it was a few years ago as I haven't done many drawings the last few years, unfortunately he's retired, I need to fine someone else as I'm getting back on the drawing board.
     
  16. chodaboy1979

    chodaboy1979 Member

    You're not far off. The bedrooms either side are 3300 and 3200. The roof space has been converted into a bedroom and i believe the 1st floor wall is supporting some of the floor joists in the loft room.
     
  17. Severntrent

    Severntrent Screwfix Select

    The plot thickens ;-), and thats why you need the SE to actually look at the loadings as flagged up by Stevie22
     
  18. chodaboy1979

    chodaboy1979 Member

    All in hand. I think Severntrent is just going to do some calcs to keep himself busy
     
  19. stevie22

    stevie22 Screwfix Select

    You beat me to the punch old chap!
     
  20. Severntrent

    Severntrent Screwfix Select

    Herewith calcs based on wide ranging loading assumptions
    Could be fine tuned by using Effective Length of beam, reduce actual deflection by basing on just Live Loads, BM due to buckling calculated instead of using conservative table figures, etc. etc.
    Pretty basic, no doubt when people are charging they can pretty them up with all sorts of cross reference's and clauses to the current BS's
    Be interesting to know what your SE comes up with and the actual loadings used
     

    Attached Files:

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