Fixing 6m 8" x 2" joist trimmer to solid wall.

Discussion in 'Getting Started FAQ' started by SGM18, Aug 16, 2020.

  1. SGM18

    SGM18 New Member

    Hi all, I'm new to this, so go lightly on me haha.

    Im wanting to fix a 6M 8x2 joist to the wall, (some call it a wallplate, others a trimmer?) will then hang joists of this. also, the fixed 6m joist will be picked up either end by inner blockwork too.

    ive never used kemfix before so therefor unsure! I was think M14/M16 threaded rod. but at what depth in the wall? 6inches?

    also, what would be wrong with the old metal anchors?

    if anybody could point me in the right direction, and some sort of instructions with depths, bolt centres etc.

    thanks in advance
     
  2. Jord86

    Jord86 Screwfix Select

    There's lots of names but let's settle on ledger plate. Use 120mm length, at roughly 600mm centres, at M14 gauge.
     
  3. SGM18

    SGM18 New Member

    @Jord86 when you say, use 120mm length, is that the depth of wall? Or entire rod? Just doesn’t seem a lot if it’s entire rod that will lose 2inches through the ledger. Or does it not need much anchor in the wall, I was thinking 4-6inches in the wall?

    also I can’t see M14 rod on SF they do 12 or 16, or would it need to be 14?

    cheers
     
  4. Jord86

    Jord86 Screwfix Select

    120mm the length of the fixing, I was assuming your wall was a cavity wall so 100mm brick or block would be the face the ledger would be fixed to, it still gives three inches into the wall which is normally plenty. Use 16 then if it's easier to source, but what does it say on your plans, as I assume this is an extension?
     
  5. SGM18

    SGM18 New Member

    @Jord86 yes it’s solid wall, adding two storey extension. Nothing on plans. Architect advised to use this method. Local regs gave me 3 options, this being the ‘easiest’. My builder mate whose helping recons the kemfix is the way forward. Just no one is giving me depths to drill solid wall etc and I’ve never used this stuff before!! I think I’ll go 4” into the wall with M16
     
  6. rogerk101

    rogerk101 Screwfix Select

    I wouldn't feel comfortable attaching a whole lot of floor joists to an 8x2 section wall plate with joist hangers. In fact I've never seen a recent wall plate that's less than 4x3.
    Which 'skin' of the brick wall does your plan show the roof trusses/rafters to be sitting on?
    I'd be attaching a 4x3 wall plate to that skin by bedding it in mortar (to spread the load), and strapping it to the wall to keep it attached.
    Unless there is something unusual about your architect's design, the weight of the joists, trusses/rafters, ridge beam, battens, tiles, etc. will be the main thing holding everything in place, plus the fact that each 'joint' will have at least 3 fixings (100mm nails, 100mm screws or M12 bolts).
    This is really something your architect should be telling you ... not a forum that knows very little about the thinking that went on in your architect's head.
     
  7. Severntrent

    Severntrent Screwfix Select

    Rogerk101 I know its early but - ledger board not wall plate
     
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  8. rogerk101

    rogerk101 Screwfix Select

    Oops. Sorry I skim read the first post and focused in on where he called it a wall plate. I take back all my 'thoughts' and 'opinions'.
    I knew I should have waited until after my coffee!
     
  9. SGM18

    SGM18 New Member

    I think I’ll give building control a ring again! Surely they’d know
     
  10. Severntrent

    Severntrent Screwfix Select

    They would know what? That a 12mm bolt can take a safe shear force of 1 tonnes and therefore 3 bolts could take the entire loading from of a floor spanning 5m over the 6m width of your ledgerboard, but you need them spaced at 600mm as directed by Jord to stop the ledgerboard deflecting. And if a brick is 100mm thick then you only need to insert the bolt to about 75mm so the load is transferred to the brickwork,could actually be less but lets play safe
     
    Jord86 likes this.
  11. Jord86

    Jord86 Screwfix Select


    I've told you how and what to use twice, your builder mate advised you of one way, if you don't, won't or can't take the advice you asked for in the first place why bother to come on here?
     
    Severntrent likes this.
  12. John Dupre

    John Dupre New Member

    Hi I am converting my loft in my mid terrace Victorian house and need to lower the ceiling / put in a structural floor for the loft room would this technique work for this too?
     
  13. SGM18

    SGM18 New Member

    into party wall or your front and back walls?
     
    John Dupre likes this.
  14. John Dupre

    John Dupre New Member

    I'd prefer to fix onto the party walls
     

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