Can you join a steel beam for a roof?

Discussion in 'Builders' Talk' started by Des1984, Sep 16, 2019.

  1. Des1984

    Des1984 Member

    Hi, I'm having some work done on an extension on my house that's falling down. Basically the roofer has said the steel beam for the new roof will come in sections and he will bolt them together yet today my bricklayer has said there's no way he should be doing that for the main beam of a roof unless he welds it as well as bolting it as it will collapse over time. I've just spoken again to the roofer and he's said it's fine to just bolt them together.
    I'm just wondering who's right? The beam is 16ft in total. Any help will be greatly appreciated! Thanks
     
  2. stevie22

    stevie22 Screwfix Select

    The roofer is correct BUT the joint needs to be properly designed and assembled
     
    Des1984 likes this.
  3. Severntrent

    Severntrent Screwfix Select

    Forth railway bridge has stood the test of time with no welding as has the Eiffel tower
     
  4. Des1984

    Des1984 Member

    Thanks for the reply. I've spoken to the roofer and found out he was just going to join the ends together but I've looked into it and apparently you have to splice it together? Anyway I've managed to get him to agree on a full beam.
     
  5. Des1984

    Des1984 Member

    Thanks for the reply. He's now told me he's going to use a full beam but he keeps on telling me that he always joins beams together. I get the impression he's not too happy I've questioned his work!
    Anyway hes told me he was going to join the beam in 4 sections using end plate connections with 6 bolts on each joint as he always does this but I'm concerned if he should be doing this? It doesn't seem like a very good way of making a load bearing roof beam strong to me. Just thought I'd ask your opinion. Thanks
     
  6. Dam0n

    Dam0n Screwfix Select

    I'm not surprised. A 16ft beam makes it alot harder to handle and transport etc. Turns the job from hard work to a real PITA.

    Don't see anything wrong with a beam being bolted. Many are and the loads they can hold are enormous.
     
    WillyEckerslike likes this.
  7. Richard_

    Richard_ Screwfix Select

    Splicing beams is very common. First of all you'd need a crane to move a 16ft beam compared to 5ft sections that can be moved with trolleys and pulley blocks. Also most domestic works have limited space so it's hard to get the thing in place in one go.

    As for the number of bolts, steel fabricators use the "green book" which gives details for beam connections, it's all very standard stuff.

    It is true that on some jobs with high stresses and limited beam depth it is necessary to use welding but that's unlikely for a domestic roof.

    Finally I'm amused by the bricklayer's suggestion of welding and bolting. The two techniques work quite differently and are not cumulative. The brickie will have seen bolts used to hold the connection still while it is welded. The bolts are redundant once the weld is in place.
     
    Des1984 likes this.
  8. Richard_

    Richard_ Screwfix Select

    Rivets.

    Lots of bolts used on this roof:

    upload_2019-9-17_10-25-30.jpeg
     
    Des1984 likes this.
  9. WillyEckerslike

    WillyEckerslike Screwfix Select

    Surely it's down to wh
    Despite the bricky's advice.....
     
  10. Chippy mick

    Chippy mick Member

    Anything like this would need to be designed by a structural engineer not a roofer or bricky. But bolting timbers together is a structural join.
     
    Des1984 likes this.
  11. Des1984

    Des1984 Member

    Thanks for all the replies. We had a structural engineer who said it needs to be a complete piece so I don't know why the roofer wanted to use sections. Think we are finally sorted out now and having a complete peice fitted but he keeps on making up excuses to not start the work. Who knows when i'll get my new roof fitted!
     
  12. DannyDoLittle

    DannyDoLittle Active Member

    When I had my extension done almost 2 years ago, the structural engineer stated that it had to be one piece.... The piece you see in the picture is 8 meters wide.. I had to have 2 of them welded together AND through bolts.. I kicked up a fuss with my SE do to the amount of steel he "calculated" because my house is a dormer bungalow... the upstairs part is within the high pitch roof and is all timber.. no brick so it's lighter but the SE was having non of it..
     

    Attached Files:

    Des1984 likes this.
  13. Richard_

    Richard_ Screwfix Select

    I'd be concerned about a contractor deliberately ignoring the SE design.

    I agree it is OK to question and ask for a connection as there are many ways to skin a cat, but it is important to check and not assume with stuff like that.

    For future ref, the joint would look something like the image below.

    Note that they join at the third point where the stresses aren't as great as at the midspan.

    https://rsjsteelbeamsonline.co.uk/c...ms-steel-fabrication-services-t-good-sons-ltd
    upload_2019-9-19_11-31-2.jpeg
     
    Jitender likes this.
  14. Des1984

    Des1984 Member

    DSC_0489.jpg Hi guys, different question. We are re-using all the slate off the roof.
    The Scaffolding has gone up today and I've just been out having a look at it with the bricky and he said there's no way that's strong enough to take all the weight of the roof tiles when the roofer takes them off. He said the legs should come out way further than they do. I had a pull on the Scaffold and I can pull it away from the building with little arm power! I'm concerned that when the roofer does turn up to start he will say its not strong enough. Any ideas?
    Picture attached
     
  15. Dam0n

    Dam0n Screwfix Select

    This bricky seems to know everything about everything...

    It'll be fine
     
    Squashrobinson likes this.
  16. Jitender

    Jitender Screwfix Select

    The beams can be spliced and end to end is a common way of getting them.

    I've just done something similar and the SE did it in 4 sections.

    They used large M20 bolts, 8 to each joint.

    My span is around 7.2m, so can't see much problem. But the steel sizes will go up in size. and all needs to be calculated by and SE.

    Maybe get another SE on the job.
     
  17. Richard_

    Richard_ Screwfix Select

    Are you contracting each trade individually? The scaffolder should be contracted by the roofer so it is set up how he wants it, and he can't blame you for delays if it's not how he wants it, you don't have to pay if the roofer says it needs to change.
     
  18. Des1984

    Des1984 Member

    Yeah we are. The roofer organised the scaffold but he couldn't get the company he usually uses. They didn't have a clue when they got here, the gaffer turned up and asked me how it was going up.
     
  19. Richard_

    Richard_ Screwfix Select

    Just be careful about being helpful, because your helpful comment can be interpreted as an instruction which can come back and bite you when you are billed for instructing extra work or delays.

    A good scaffolder always asks how you want it arranged. Different workers prefer different arrangements such as ladder location, do you need an arm for a pulley block, will there be a waste shute, where's the skip going.

    There's not really a standard level for the decks either as it depends on what refurb is a happening, eg do you need to leave windows clear to work on them. I see you don't have a middle deck, so does that mean you're not going to do any work to that wall? There's also a worrying lack of toe boards on the top deck.

    Much better to ask than have to come back to change it. I suspect you're being exposed to the normal conversations that take place between trades, the sort of stuff a main contractor/builder would take care of.
     
    Last edited: Sep 19, 2019
  20. sospan

    sospan Screwfix Select

    I would also be concerned because of the proximity of the road. There is no barrier to keep the public away from the work especially since there is no pavement and pedestrians could wander close to the work
     

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