Joists over span tables

Discussion in 'Carpenters' Talk' started by Rods, Jan 14, 2014.

  1. Rods

    Rods New Member

    Hi all,

    A couple of questions for you all,

    I want to put in a floor that is walk-on-able in my loft. Maybe even put in a few bits of furniture up there.

    The current ceiling joists run at 5.6m and 5.2m and are only 100mm x 50mm. The span table books say i can use 220 x 75 C24 for the 5.2m span but the table runs out just after that 5.43 and that is with minimal load.

    Does that mean I need to split the span for the room by using some Steel or something ?

    If I don't need to split the span, then when I run the new joists along side the old ones, I have ceiling binders (I think they are called) which run over the old joists. I will need to remove them, so then do I just fix the new joists using screws or something to the old joists so the ceiling doesnt sag ?

    Ideally I don't want to go over the old joists as that would mean losing some head room and there isnt a lot up there as it is, also if i go over the old joists as the wall attaches to my neighbour there is no supporting wall to rest the ends of the joists on.

    Attached if a layout of the walls. Red lines are current joists and blue dot is neighbour.

    Any help appreciated.

    Rod
     

    Attached Files:

  2. Phil the Paver

    Phil the Paver Screwfix Select

    reading this makes me think that you don't have planning permission for this, if you did im sure the drawing would not have any new joists connected to the old joists, all new joists would be built into/hung off the external walls or hung of new steels.
     
  3. Sean_ork

    Sean_ork Screwfix Select

    the works, as described don't require PP as it's almost certainly PD but it does sound as if due regard to building regulations is not being given

    my advise would be to get this project properly designed by someone qualified and insured, leave it to them to specify timbers and/or steels
     
  4. wiggy

    wiggy Screwfix Select

    On the longer span (extra 400mm) I would just close up the centres and throw another couple of joists up there.

    But tbh, you need to take the advice of phil and sean above. Its a massive job for someone asking for this sort of advice.

    Its really not a diy job

    You will have to open up the roof to get them up there, thats some lump of timber. You're not getting that lot through the hatch.

    For all the work involved get someone to spec it up properly.
     

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